[top]
000
FXUS66 KPDT 232318 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
320 PM PST MON NOV 23 2009
UPDATED AVIATION DISCUSSION
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT. LOW PRESSURE ENTERING
THE PACNW WILL CONTINUE TO SPREAD CLOUDS INTO THE AREA TONIGHT.
SHOWERS WILL ALSO DEVELOP ALONG THE EAST SLOPES OF THE WASHINGTON
CASCADES AND THEN SPREAD EAST INTO PORTIONS OF THE WASHINGTON
COLUMBIA BASIN AND NORTHERN BLUE MOUNTAINS OVERNIGHT. THE PCPN
SHOULD BE MOSTLY LIQUID BUT ACROSS THE HIGHER ELEVATIONS THIS COULD
BE SOME SNOW AS WELL. AS THE SYSTEM SAGS SOUTH AND EAST THE PCPN
WILL MIGRATE INTO THE OREGON PORTIONS OF THE BASIN AND BLUE MTNS AND
SURROUNDING AREA OVERNIGHT. MOISTURE LINGERS OVER THE BLUE/WALLOWA
MTNS AND ALONG THE EAST SLOPES OF THE WA CASCADES TOMORROW WITH
SHOWERS CONTINUING. WITH THE CLEARING SKIES SOME FOG MAY DEVELOP
OVER THE LOWER COLUMBIA BASIN TUESDAY NIGHT. A RIDGE OF HIGH
PRESSURE MOVES INTO THE REGION WEDNESDAY SHOVING ANOTHER STORM
SYSTEM NORTH AND AWAY FROM OUR AREA. HOWEVER ENOUGH MOISTURE WILL
SKIRT THE FAR NW AND SOME SHOWERS WILL DEVELOP OVER THE EAST SLOPES
OF THE WA CASCADES WEDNESDAY AND WEDNESDAY NIGHT. FURTHER EAST FOG
SHOULD DEVELOP AND EXPAND IN COVERAGE TO NOT ONLY INCLUDE THE LOWER
COLUMBIA BASIN BUT ALSO INTO PORTIONS OF THE BLUE MTN FOOTHILLS AND
PERHAPS THE GORGE AS WELL WEDNESDAY NIGHT.
.LONG TERM...THURSDAY THROUGH MONDAY...AN UPPER LEVEL RIDGE WILL
MOVE EAST OF THE AREA THURSDAY. LINGERING EFFECTS OF THE RIDGE WILL
KEEP PATCHY FOG IN THE LOWER COLUMBIA BASIN. A SPLITTING UPPER LEVEL
LOW AND FRONT WILL APPROACH THE CASCADES THURSDAY AFTERNOON...AND
MOVE OVER EASTERN WASHINGTON AND OREGON THURSDAY NIGHT AND FRIDAY.
THIS SYSTEM WILL BRING SOME PRECIPITATION AND WINDS TO THE AREA.
SATURDAY THE ENSEMBLES START TO DIVERGE INDICATING MORE UNCERTAINTY
IN THE FORECAST. BOTH THE GFS AND ECMWF INDICATE A BUILDING RIDGE
SATURDAY NIGHT...BUT THIS PATTERN DOES NOT HAVE ANY RUN TO RUN
CONSISTENCY. TRENDED FORECAST TO DRIER RIDGE-LIKE PATTERN...BUT DID
KEEP SOME LOW POPS IN THE MOUNTAINS DUE TO LOW CONFIDENCE. ADDED
FOG/FREEZING FOG TO THE LOWER COLUMBIA BASIN SATURDAY NIGHT THROUGH
MONDAY NIGHT WITH SPREADING PATTERN THROUGH TIME. COONFIELD
&&
.AVIATION...0Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH TONIGHT
WITH INCREASING MID AND HIGH CLOUDS. ANOTHER WEATHER DISTURBANCE
WILL MOVE INTO THE AREA OVERNIGHT WITH ANOTHER CHANCE OF RAIN AND
MOUNTAIN SNOW. KRDM IN CENTRAL OREGON WILL LIKELY NOT SEE ANY
PRECIPITATION FROM THIS SYSTEM. THERE MAY BE BRIEF PERIODS OF MVFR
OVERNIGHT IN RAIN/SNOW SHOWERS...ESPECIALLY AT KDLS AND KYKM...AND
TO A LESSER DEGREE AT KPDT AND KALW. WINDS MAINLY LESS THAN 15
KTS...BUT PERHAPS 10 TO 20 KTS AT TIMES NEAR SHOWERS. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 35 48 33 44 / 30 20 0 0
ALW 37 47 35 41 / 30 20 0 0
PSC 34 50 32 46 / 30 10 0 0
YKM 31 48 30 45 / 40 20 0 0
HRI 33 48 31 45 / 30 10 0 0
ELN 31 47 31 44 / 40 20 10 0
RDM 28 52 25 50 / 10 10 0 0
LGD 29 44 27 43 / 20 30 10 0
GCD 28 47 27 52 / 10 10 0 0
DLS 36 51 37 52 / 40 20 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TUESDAY : GREEN
WEDNESDAY : GREEN
THURSDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97/76/76
[top]
000
FXUS66 KPQR 232251 CCA
AFDPQR
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PORTLAND OR
250 PM PST MON NOV 23 2009
.SYNOPSIS...A WEAK COLD FRONT WILL SAG SE INTO NW OREGON TONIGHT.
THE FRONT WILL STALL LATE TONIGHT...THEN LIFT NE AS A WARM FRONT ON
TUE. THE NEXT FRONTAL SYSTEM IS NOT EXPECTED TO MOVE IN UNTIL LATE
THURSDAY.
&&
.SHORT TERM...NOT MUCH TO TALK ABOUT THROUGH WEDNESDAY. A WEAK FRONT
OFFSHORE WILL BE THE MAIN THREAT FOR RAIN TONIGHT MAINLY OVER
THE NW PART OF THE FORECAST AREA...WHERE ISENTROPIC LIFT IS BEST
AHEAD OF THE WARM FRONT OFFSHORE.
MODELS INDICATE A COLD FRONT SAGGING DOWN INTO THE REGION TONIGHT.
WILL NEED TO INCLUDE POPS MOST NORTHERN AREAS TONIGHT AND
EARLY TUE WITH BAROCLINIC ZONE OVER THE AREA...BUT WITH WEAK DYNAMICS
POPS WILL BE LIMITED TO CHANCE. FRONT LIFTS BACK TO THE N LATE TUE
AND TUE NIGHT WITH THE UPPER RIDGE REBOUNDING...RESULTING IN
DIMINISHING POPS BY TUE NIGHT...AND A DRY DAY WED. WHICH WILL SET THE
STAGE FOR SOME FOG IN THE VALLEYS WEDNESDAY MORNING. WOLFE
.LONG TERM...THE MODELS SHOW A SYSTEM MOVING THROUGH THURSDAY NIGHT
AND FRIDAY THAT SHOWS SOME SIGNS OF SPLITTING WITH SOME OF THE
ENERGY DIGGING INTO NORTHERN CALIFORNIA...SO AM NOT GOING QUITE AS
CONSOLIDATED AS THE LATEST 12Z GFS MODEL. A TRAILING SHORT WAVE FROM
THE NORTHWEST KEEPS A BIT OF PRECIPITATION GOING FRIDAY NIGHT INTO
SATURDAY. THEN THE MODELS SHOW SOME RIDGING OVER THE PACIFIC
NORTHWEST DUE TO A DIGGING/DEVELOPING SYSTEM OUT 140W. THIS SHOULD
BRING DRYING WITH THE INCREASED POSSIBILITY OF VALLEY FOG. THE
MODELS DIVERGE FOR EARLY NEXT WEEK WITH THE LAST COUPLE OF ECMWF
RUNS WHILE THE GFS IS DRY STILL. HOWEVER...THE GFS ENSEMBLES HAVE A
VERY LARGE SPREAD AT THAT POINT. FOR NOW HAVE GONE WITH SOME POP FOR
MONDAY BUT BELOW CLIMO TO ACCOUNT FOR THE ECMWF AND THE ENSEMBLE
SPREAD. TOLLESON
&&
.AVIATION...A SLOW MOVING WARM FRONT ARRIVES AT THE PACIFIC NW COAST
THIS AFTERNOON...BRINGING MVFR CONDITIONS AND AREAS OF LIGHT RAIN TO
THE COAST THROUGH THE EVENING. INLAND VISIBILITIES REMAIN AT VFR
EXCEPT SOME AREAS MAY FLIRT WITH MVFR THIS EVENING AS AREAS OF LIGHT
RAIN MOVE INLAND...POSSIBLY AS EARLY AS 06Z. MVFR CIGS/VSBYS MAY
LINGER WELL INTO THE DAY TUE...DUE TO ABUNDANT LOW LEVEL MOISTURE
AND THE LACK OF SIGNIFICANT WIND TO MIX THE LOWER LAYERS.
KPDX AND APPROACHES...VFR CONDITIONS TO REMAIN THROUGH 06Z TONIGHT.
SOME LOCAL MVFR DEVELOPING LATER THIS EVENING AS AREAS OF LIGHT RAIN
DEVELOP. AREAS MVFR MAY LINGER WELL INTO THE DAY TUE...BUT MAINLY
OUTSIDE OF THE CITY. WEAGLE/LRAMIREZ
&&
.MARINE...LOW PRESSURE IS MOVING INTO BRITISH COLUMBIA TODAY...
PUSHING A WARM FRONT INTO WASHINGTON AND OREGON. ASSOCIATED COLD
FRONT EXTENDS SW FROM LOW AND WILL NOT DIRECTLY MOVE THROUGH WATERS
UNTIL MIDWEEK. WINDS THUS FAR ASSOCIATED WITH THE FRONTAL SYSTEM
HAVE REMAINED BELOW GALE...WITH MOST GUSTS AROUND 25 KNOTS. AS THE
MAIN LOW TRAVELS FURTHER INLAND INTO CANADA...WINDS ASSOCIATED WITH
THE FRONT WILL EASE BELOW SCA CRITERIA OVERNIGHT. SEAS APPEAR TO BE
BRIEFLY FALLING BELOW 10 FT THIS AFTERNOON AT SOME LOCATIONS...BUT
EXPECT WEST SWELL ASSOCIATED WITH THE LOW PRESSURE SYSTEM TO PUSH
SEAS BACK UP ABOVE 10 FT THIS EVENING. THUS WILL LEAVE SCA FOR HAZ
SEAS IN EFFECT THROUGH TUE. THE RATHER LONG PERIOD SWELL IMPACTING
THE BAR WILL CONTINUE ROUGH BAR CONDITIONS THROUGH TUE DESPITE THE
WEAK EBBS. GENERALLY TRANQUIL WEATHER THEN EXPECTED INTO WED...THEN
THE COLD FRONT WILL FINALLY SLIDE ACROSS THE COASTAL WATERS WED
NIGHT/THU. SOME MODELS SHOW THE POSSIBILITY OF A STRONG LOW
DEVELOPING ALONG THIS FRONT OFF THE OREGON COAST WED NIGHT OR EARLY
THU...WILL NEED TO MONITOR THIS FOR POTENTIAL GALES DURING THAT TIME
PERIOD. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO
FLORENCE OUT 0-60 NM THROUGH TUE.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR THROUGH
TUE AFTERNOON.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KPDT 232237 CCA
AFDPDT
AREA FORECAST DISCUSSION...COR
NATIONAL WEATHER SERVICE PENDLETON OR
230 PM PST MON NOV 23 2009
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT. LOW PRESSURE ENTERING
THE PACNW WILL CONTINUE TO SPREAD CLOUDS INTO THE AREA TONIGHT.
SHOWERS WILL ALSO DEVELOP ALONG THE EAST SLOPES OF THE WASHINGTON
CASCADES AND THEN SPREAD EAST INTO PORTIONS OF THE WASHINGTON
COLUMBIA BASIN AND NORTHERN BLUE MOUNTAINS OVERNIGHT. THE PCPN
SHOULD BE MOSTLY LIQUID BUT ACROSS THE HIGHER ELEVATIONS THIS COULD
BE SOME SNOW AS WELL. AS THE SYSTEM SAGS SOUTH AND EAST THE PCPN
WILL MIGRATE INTO THE OREGON PORTIONS OF THE BASIN AND BLUE MTNS AND
SURROUNDING AREA OVERNIGHT. MOISTURE LINGERS OVER THE BLUE/WALLOWA
MTNS AND ALONG THE EAST SLOPES OF THE WA CASCADES TOMORROW WITH
SHOWERS CONTINUING. WITH THE CLEARING SKIES SOME FOG MAY DEVELOP
OVER THE LOWER COLUMBIA BASIN TUESDAY NIGHT. A RIDGE OF HIGH
PRESSURE MOVES INTO THE REGION WEDNESDAY SHOVING ANOTHER STORM
SYSTEM NORTH AND AWAY FROM OUR AREA. HOWEVER ENOUGH MOISTURE WILL
SKIRT THE FAR NW AND SOME SHOWERS WILL DEVELOP OVER THE EAST SLOPES
OF THE WA CASCADES WEDNESDAY AND WEDNESDAY NIGHT. FURTHER EAST FOG
SHOULD DEVELOP AND EXPAND IN COVERAGE TO NOT ONLY INCLUDE THE LOWER
COLUMBIA BASIN BUT ALSO INTO PORTIONS OF THE BLUE MTN FOOTHILLS AND
PERHAPS THE GORGE AS WELL WEDNESDAY NIGHT.
.LONG TERM...THURSDAY THROUGH MONDAY...AN UPPER LEVEL RIDGE WILL
MOVE EAST OF THE AREA THURSDAY. LINGERING EFFECTS OF THE RIDGE WILL
KEEP PATCHY FOG IN THE LOWER COLUMBIA BASIN. A SPLITTING UPPER LEVEL
LOW AND FRONT WILL APPROACH THE CASCADES THURSDAY AFTERNOON...AND
MOVE OVER EASTERN WASHINGTON AND OREGON THURSDAY NIGHT AND FRIDAY.
THIS SYSTEM WILL BRING SOME PRECIPITATION AND WINDS TO THE AREA.
SATURDAY THE ENSEMBLES START TO DIVERGE INDICATING MORE UNCERTAINTY
IN THE FORECAST. BOTH THE GFS AND ECMWF INDICATE A BUILDING RIDGE
SATURDAY NIGHT...BUT THIS PATTERN DOES NOT HAVE ANY RUN TO RUN
CONSISTENCY. TRENDED FORECAST TO DRIER RIDGE-LIKE PATTERN...BUT DID
KEEP SOME LOW POPS IN THE MOUNTAINS DUE TO LOW CONFIDENCE. ADDED
FOG/FREEZING FOG TO THE LOWER COLUMBIA BASIN SATURDAY NIGHT THROUGH
MONDAY NIGHT WITH SPREADING PATTERN THROUGH TIME. COONFIELD
&&
.AVIATION...18Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE DAY
TODAY WITH INCREASING MID AND HIGH CLOUDS THIS AFTERNOON. ANOTHER
WEATHER DISTURBANCE WILL MOVE INTO THE AREA OVERNIGHT TONIGHT WITH
ANOTHER CHANCE OF RAIN AND MOUNTAIN SNOW. KRDM IN CENTRAL OREGON
WILL LIKELY NOT SEE ANY PRECIPITATION FROM THIS SYSTEM. THERE MAY BE
BRIEF PERIODS OF MVFR TONIGHT IN RAIN/SNOW SHOWERS...ESPECIALLY AT
KDLS...KYKM AND KPSC...AND TO A LESSER DEGREE AT KPDT AND KALW.
WINDS MAINLY LESS THAN 15 KTS...BUT PERHAPS 15 TO 20 KTS AT TIMES
NEAR SHOWERS. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 35 48 33 44 / 30 20 0 0
ALW 37 47 35 41 / 30 20 0 0
PSC 34 50 32 46 / 30 10 0 0
YKM 31 48 30 45 / 40 20 0 0
HRI 33 48 31 45 / 30 10 0 0
ELN 31 47 31 44 / 40 20 10 0
RDM 28 52 25 50 / 10 10 0 0
LGD 29 44 27 43 / 20 30 10 0
GCD 28 47 27 52 / 10 10 0 0
DLS 36 51 37 52 / 40 20 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TUESDAY : GREEN
WEDNESDAY : GREEN
THURSDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97/76/76
000
FXUS66 KPDT 232230
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
230 PM PST MON NOV 23 2009
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT. LOW PRESSURE ENTERING
THE PACNW WILL CONTINUE TO SPREAD CLOUDS INTO THE AREA TONIGHT.
SHOWERS WILL ALSO DEVELOP ALONG THE EAST SLOPES OF THE WASHINGTON
CASCADES AND THEN SPREAD EAST INTO PORTIONS OF THE WASHINGTON
COLUMIA BASIN AND NORTHERN BLUE MOUNTAINS OVERNIGHT. THE PCPN SHOULD
BE MOSTLY LIQUID BUT ACROSS THE HIGHER ELEVATIONS THIS COULD BE SOME
SNOW AS WELL. AS THE SYSTEM SAGS SOUTH AND EAST THE PCPN WILL
MIGRATE INTO THE OREGON PORTIONS OF THE BASIN AND BLUE MTNS AND
SURROUNDING AREA. MOISTURE LINGERS OVER THE BLUE/WALLOWA MTNS AND
ALONG THE EAST SLOPES OF THE WA CASCADES TOMORROW WITH SHOWERS
CONTINUING. WITH THE CLEARING SKIES SOME FOG MAY DEVELOP OVER THE
LOWER COLUMBIA BASIN TUESDAY NIGHT. A RIDGE OF HIGH PRESSURE MOVES
INTO THE REGION WEDNESDAY SHOVING ANOTHER STORM SYSTEM NORTH AND
AWAY FROM OUR AREA. HOWEVER ENOUGH MOISTURE WILL SKIRT THE FAR NW
AND SOME SHOWERS WILL DEVELOP OVER THE EAST SLOPES OF THE WA
CASCADES WEDNESDAY AND WEDNESDAY NIGHT. FURTHER EAST FOG SHOULD
DEVLOP AND EXPAND IN COVERAGE TO NOT ONLY INCLUDE THE LOWER COLUMBIA
BASIN BUT ALSO INTO PORTIONS OF THE BLUE MTN FOOTHILLS AND PERHAPS
THE GORGE AS WELL.
.LONG TERM...THURSDAY THROUGH MONDAY...AN UPPER LEVEL RIDGE WILL
MOVE EAST OF THE AREA THURSDAY. LINGERING EFFECTS OF THE RIDGE WILL
KEEP PATCHY FOG IN THE LOWER COLUMBIA BASIN. A SPLITTING UPPER LEVEL
LOW AND FRONT WILL APPROACH THE CASCADES THURSDAY AFTERNOON...AND
MOVE OVER EASTERN WASHINGTON AND OREGON THURSDAY NIGHT AND FRIDAY.
THIS SYSTEM WILL BRING SOME PRECIPITATION AND WINDS TO THE AREA.
SATURDAY THE ENSEMBLES START TO DIVERGE INDICATING MORE UNCERTAINTY
IN THE FORECAST. BOTH THE GFS AND ECMWF INDICATE A BUILDING RIDGE
SATURDAY NIGHT...BUT THIS PATTERN DOES NOT HAVE ANY RUN TO RUN
CONSISTENCY. TRENDED FORECAST TO DRIER RIDGE-LIKE PATTERN...BUT DID
KEEP SOME LOW POPS IN THE MOUNTAINS DUE TO LOW CONFIDENCE. ADDED
FOG/FREEZING FOG TO THE LOWER COLUMBIA BASIN SATURDAY NIGHT THROUGH
MONDAY NIGHT WITH SPREADING PATTERN THROUGH TIME. COONFIELD
&&
.AVIATION...18Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE DAY
TODAY WITH INCREASING MID AND HIGH CLOUDS THIS AFTERNOON. ANOTHER
WEATHER DISTURBANCE WILL MOVE INTO THE AREA OVERNIGHT TONIGHT WITH
ANOTHER CHANCE OF RAIN AND MOUNTAIN SNOW. KRDM IN CENTRAL OREGON
WILL LIKELY NOT SEE ANY PRECIPITATION FROM THIS SYSTEM. THERE MAY BE
BRIEF PERIODS OF MVFR TONIGHT IN RAIN/SNOW SHOWERS...ESPECIALLY AT
KDLS...KYKM AND KPSC...AND TO A LESSER DEGREE AT KPDT AND KALW.
WINDS MAINLY LESS THAN 15 KTS...BUT PERHAPS 15 TO 20 KTS AT TIMES
NEAR SHOWERS. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 35 48 33 44 / 30 20 0 0
ALW 37 47 35 41 / 30 20 0 0
PSC 34 50 32 46 / 30 10 0 0
YKM 31 48 30 45 / 40 20 0 0
HRI 33 48 31 45 / 30 10 0 0
ELN 31 47 31 44 / 40 20 10 0
RDM 28 52 25 50 / 10 10 0 0
LGD 29 44 27 43 / 20 30 10 0
GCD 28 47 27 52 / 10 10 0 0
DLS 36 51 37 52 / 40 20 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TUESDAY : GREEN
WEDNESDAY : GREEN
THURSDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97/76/76
000
FXUS66 KPQR 232222
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
221 PM PST MON NOV 23 2009
.SYNOPSIS...A WEAK COLD FRONT WILL SAG SE INTO NW OREGON TONIGHT.
THE FRONT WILL STALL LATE TONIGHT...THEN LIFT NE AS A WARM FRONT ON
TUE. THE NEXT FRONTAL SYSTEM IS NOT EXPECTED TO MOVE IN UNTIL LATE
THURSDAY.
&&
.SHORT TERM...NOT MUCH TO TALK ABOUT THROUGH WEDNESDAY. A WEAK FRONT
OFFSHORE WILL BE THE MAIN THREAT FOR RAIN TONIGHT MAINLY OVER
THE NW PART OF THE FORECAST AREA...WHERE ISENTROPIC LIFT IS BEST
AHEAD OF THE WARM FRONT OFFSHORE.
MODELS INDICATE A COLD FRONT SAGGING DOWN INTO THE REGION TONIGHT.
WILL NEED TO INCLUDE POPS MOST NORTHERN AREAS TONIGHT AND
EARLY TUE WITH BAROCLINIC ZONE OVER THE AREA...BUT WITH WEAK DYNAMICS
POPS WILL BE LIMITED TO CHANCE. FRONT LIFTS BACK TO THE N LATE TUE
AND TUE NIGHT WITH THE UPPER RIDGE REBOUNDING...RESULTING IN
DIMINISHING POPS BY TUE NIGHT...AND A DRY DAY WED. WHICH WILL SET THE
STAGE FOR SOME FOG IN THE VALLEYS WEDNESDAY MORNING. WOLFE
.LONG TERM...THE MODELS SHOW A SYSTEM MOVING THROUGH THURSDAY NIGHT
AND FRIDAY THAT SHOWS SOME SIGNS OF SPLITTING WITH SOME OF THE
ENERGY DIGGING INTO NORTHERN CALIFORNIA...SO AM NOT GOING QUITE AS
CONSOLIDATED AS THE LATEST 12Z GFS MODEL. A TRAILING SHORT WAVE FROM
THE NORTHWEST KEEPS A BIT OF PRECIPITATION GOING FRIDAY NIGHT INTO
SATURDAY. THEN THE MODELS SHOW SOME RIDGING OVER THE PACIFIC
NORTHWEST DUE TO A DIGGING/DEVELOPING SYSTEM OUT 140W. THIS SHOULD
BRING DRYING WITH THE INCREASED POSSIBILITY OF VALLEY FOG. THE
MODELS DIVERGE FOR EARLY NEXT WEEK WITH THE LAST COUPLE OF ECMWF
RUNS WHILE THE GFS IS DRY STILL. HOWEVER...THE GFS ENSEMBLES HAVE A
VERY LARGE SPREAD AT THAT POINT. FOR NOW HAVE GONE WITH SOME POP FOR
MONDAY BUT BELOW CLIMO TO ACCOUNT FOR THE ECMWF AND THE ENSEMBLE
SPREAD. TOLLESON
&&
.AVIATION...MUCH MORE TRANQUIL TODAY. PRIMARILY VFR CONDITIONS
ACROSS THE REGION. A WARM FRONT APPROACHING FROM THE WEST WILL
SPREAD AREAS OF MVFR WITH OCCASIONAL RA ALONG THE COAST AROUND 20Z.
MAY SEE SOME SPRINKLES INLAND AS THE WARM FRONT PASSES THROUGH...BUT
REMAINING GENERALLY DRY WITH VFR THROUGH 02Z.
KPDX AND APPROACHES...NO ADVERSE WEATHER IMPACTS EXPECTED. VFR
CONDITIONS TO REMAIN THROUGH 06Z TONIGHT.
&&
.MARINE...LOW PRESSURE IS MOVING INTO BRITISH COLUMBIA TODAY...
PUSHING A WARM FRONT INTO WASHINGTON AND OREGON. ASSOCIATED COLD
FRONT EXTENDS SW FROM LOW AND WILL NOT DIRECTLY MOVE THROUGH WATERS
UNTIL MIDWEEK. WINDS THUS FAR ASSOCIATED WITH THE FRONTAL SYSTEM
HAVE REMAINED BELOW GALE...WITH MOST GUSTS AROUND 25 KNOTS. AS THE
MAIN LOW TRAVELS FURTHER INLAND INTO CANADA...WINDS ASSOCIATED WITH
THE FRONT WILL EASE BELOW SCA CRITERIA OVERNIGHT. SEAS APPEAR TO BE
BRIEFLY FALLING BELOW 10 FT THIS AFTERNOON AT SOME LOCATIONS...BUT
EXPECT WEST SWELL ASSOCIATED WITH THE LOW PRESSURE SYSTEM TO PUSH
SEAS BACK UP ABOVE 10 FT THIS EVENING. THUS WILL LEAVE SCA FOR HAZ
SEAS IN EFFECT THROUGH TUE. THE RATHER LONG PERIOD SWELL IMPACTING
THE BAR WILL CONTINUE ROUGH BAR CONDITIONS THROUGH TUE DESPITE THE
WEAK EBBS. GENERALLY TRANQUIL WEATHER THEN EXPECTED INTO WED...THEN
THE COLD FRONT WILL FINALLY SLIDE ACROSS THE COASTAL WATERS WED
NIGHT/THU. SOME MODELS SHOW THE POSSIBILITY OF A STRONG LOW
DEVELOPING ALONG THIS FRONT OFF THE OREGON COAST WED NIGHT OR EARLY
THU...WILL NEED TO MONITOR THIS FOR POTENTIAL GALES DURING THAT TIME
PERIOD. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO
FLORENCE OUT 0-60 NM THROUGH TUE.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR THROUGH
TUE AFTERNOON.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
[top]
000
FXUS66 KMFR 232207
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
205 PM PST MON NOV 23 2009
.SHORT TERM...DRY WEATHER IS IN STORE AS WEAK HIGH PRESSURE OVER THE
REGION WILL GRADUALLY STRENGTHEN THROUGH WEDNESDAY. EXPECT AREAS OF
FOG TO DEVELOP IN THE VALLEYS OF SOUTHWEST OREGON AND WESTERN
SISKIYOU COUNTY CALIFORNIA LATE TONIGHT OR EARLY TUESDAY MORNING.
MOST LOCATIONS SHOULD CLEAR OUT BY EARLY AFTERNOON. VALLEY FOG WILL
LIKELY DEVELOP AGAIN LATE TUESDAY NIGHT OR EARLY WEDNESDAY MORNING.
HIGH PRESSURE WILL WEAKEN WEDNESDAY NIGHT AS A COLD FRONT SLOWLY
APPROACHES THE COAST. THE LATEST TIMING BRINGS THE FRONT TO THE
COAST THURSDAY AFTERNOON THEN INLAND DURING THE EVENING. SOUTHERLY
WINDS IN ADVANCE OF THE FRONT WILL INCREASE ALONG THE COAST BUT ARE
EXPECTED TO REMAIN BELOW WARNING CRITERIA. AS FAR AS RAINFALL TOTALS
WITH THIS SYSTEM...NOT THAT IMPRESSIVE FOR THIS TIME OF YEAR.
PORTIONS OF THE COAST COULD GET BETWEEN ONE AND TWO INCHES...THEN
DROPPING OFF THE FURTHER INLAND YOU GO. SNOW LEVELS WILL LOWER TO
AROUND PASS LEVEL BY LATE THURSDAY NIGHT WITH THE POTENTIAL OF 3 TO
6 INCHES OF SNOW ACCUMULATION IN THE CASCADES AND SISKIYOUS. HOLTZ
.LONG TERM...AFTER THE LOW PRESSURE SYSTEM EXITS THE AREA FRIDAY
MORNING...BOTH THE GFS AND ECMWF DO NOT WASTE ANY TIME BRINGING IN
ANOTHER SHORTWAVE TROUGH THROUGH FRIDAY NIGHT INTO SATURDAY. RAIN
AND SNOW AMOUNTS WILL LIKELY BE LIGHT TO MODERATE WITH THIS
FEATURE...BUT RUN TO RUN CONSISTENCY IS NOT GOOD...AND THERE IS LOW
CONFIDENCE IN THE MODEL SOLUTIONS. SNOW LEVELS REMAIN AROUND 4000
FEET THROUGH SATURDAY MORNING AND THEN BEGIN TO RISE SUNDAY THROUGH
TUESDAY WITH UPPER RIDGING BUILDING ACROSS THE AREA. ANOTHER FAIRLY
DRY PERIOD WITH MORNING VALLEY FOG AND AFTERNOON SUN IS LIKELY
SUNDAY THROUGH EARLY TUESDAY. RECENT MODEL TRENDS TEND TO DEEPEN
THE TROUGHS EARLY NEXT WEEK OVER THE CENTRAL PLAINS AND AROUND 140W
OVER THE EPAC WATERS...WHICH SHOULD YIELD DRY AND WARMER WEATHER
OVER CALIFORNIA AND OREGON. CPC 6-10 DAY OUTLOOK REFLECTS THIS
IDEA. MP/NK
&&
.AVIATION...INTERIOR VALLEY FOG WILL DEVELOP LATE TONIGHT FOR AREAS
OF IFR CONDITIONS...OTHERWISE EXPECT VFR CONDITIONS AROUND THE
REGION OVERNIGHT.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS
UNTIL 10 PM PST TUESDAY FOR PZZ350-PZZ356-PZZ370-PZZ376.
$$
RH/MP/NK
[top]
000
FXUS65 KBOI 232204
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
304 PM MST MON NOV 23 2009
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...OTHER THAN A PASSING
MAINLY DRY COLD FRONT TUESDAY LOOK FOR A WEAK INVERSION TONIGHT
AND STRONGER AND MORE MOIST INVERSION TUESDAY NIGHT INTO THE LONG
TERM. AFTERNOON EROSION OF THE INVERSION AND ACCOMPANYING
STRATUS/FOG IS EXPECTED WITH THE POSSIBLE EXCEPTION OF THE AREA
FROM VALE TO WEST OF MIDDLETON IDAHO WEDNESDAY. TEMPERATURES
GENERALLY ON TRACKOR SLIGHT WARMER THAN GUIDANCE WITH SOME
CHANGES MADE FOR INVERSION WEST OF BOISE AND AT JEROME. LIGHT WINDS
OF LESS THAN 5 KTS AVERAGE AND LOW MIXING LEVEL OF 2000 FT AGL OR
LESS LOOK TO REMAIN OVER THE LOWER TREASURE VALLEY UNTIL TUESDAY
AFTERNOON.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...INVERSION HOLDS ON
INTO THURSDAY. EXPECT FOG/STRATUS TO RETURN TO THE LOWER TREASURE
VALLEY AND IN VICINITY OF THE SNAKE RIVER EARLY THURSDAY MORNING.
SURFACE WINDS AND WINDS ALOFT INCREASE THROUGH THE DAY WHICH WILL
HELP MIX OUT ALL BUT THE LOWEST ELEVATIONS ALONG THE SNAKE RIVER. A
STORM SYSTEM IS STILL TIMED FOR FRIDAY INCREASING THE CHANCE OF
VALLEY RAIN AND MTN SNOW. A SECOND SYSTEM DROPS INTO THE
INTERMOUNTAIN WEST EARLY SATURDAY CONTINUING THE CHANCE OF PRECIP.
AMOUNTS WITH THESE SYSTEMS WILL BE FAIRLY LIGHT AS BAND OF HIGHER PW
VALUES REMAIN SOUTH AND WEST OF THE REGION. UPPER RIDGE WITH WARM
AIR ALOFT REDEVELOPS OVER THE AREA FOR SUN/MON BRINGING RETURN TO AN
INVERSION PATTERN.
&&
.AVIATION...ISOLATED IFR IN SNOW SHOWERS TONIGHT OVER THE MTNS NORTH
OF KBKE-KMYL LINE. LOCAL IFR IN FOG DEVELOPING IN LOWER TREASURE
VALLEY WITH POSSIBLE IFR STRATUS OVER THE WESTERN MAGIC VALLEY EARLY
TUESDAY MORNING. FOG AND STRATUS INCREASES IN COVERAGE TUESDAY NIGHT
AND WEDNESDAY.
KBOI WILL LIKELY DEVELOP MVFR-IFR CONDITIONS BY EARLY WEDNESDAY
MORNING. IF FOG DEVELOPS BEFORE THE LOW STRATUS WE COULD BE CLOSE TO
MINIMUMS WEDNESDAY MORNING. DOES LOOK HOPEFUL THAT CONDITIONS CLEAR
WEDNESDAY AFTERNOON BEFORE REDEVELOPING WEDNESDAY NIGHT.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
SHORT TERM...VM
LONG TERM....DG/DD
AVIATION.....DG
000
FXUS66 KPDT 231731 AAB
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
930 AM PST MON NOV 23 2009
UPDATED AVIATION DISCUSSION
.SHORT TERM...HIGH PRESSURE THAT IS PROVIDING A MOSTLY SUNNY
BEGINNING WILL GIVE WAY TO A DISTURBANCE MOVG INTO THE PACNW THIS
AFTERNOON. THIS SHOULD SPREAD CLOUDS INTO PORTIONS OF THE AREA
ESPECIALLY OVER THE WA CASCADES WHERE A FEW SHOWERS MAY DEVELOP LATE
THIS AFTERNOON AND THEN SPREAD EAST LATER ON. OTHERWISE HIGH TEMPS
SEEM TO BE IN THE BALLPARK AND THE SHORT TERM FORECAST APPEARS ON
TRACK FOR NOW.
&&
.AVIATION DISCUSSION...18Z TAFS...VFR CONDITIONS WILL PREVAIL
THROUGH THE DAY TODAY WITH INCREASING MID AND HIGH CLOUDS THIS
AFTERNOON. ANOTHER WEATHER DISTURBANCE WILL MOVE INTO THE AREA
OVERNIGHT TONIGHT WITH ANOTHER CHANCE OF RAIN AND MOUNTAIN SNOW.
KRDM IN CENTRAL OREGON WILL LIKELY NOT SEE ANY PRECIPITATION FROM
THIS SYSTEM. THERE MAY BE BRIEF PERIODS OF MVFR TONIGHT IN RAIN/SNOW
SHOWERS...ESPECIALLY AT KDLS...KYKM AND KPSC...AND TO A LESSER
DEGREE AT KPDT AND KALW. WINDS MAINLY LESS THAN 15 KTS...BUT PERHAPS
15 TO 20 KTS AT TIMES NEAR SHOWERS. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 47 34 48 33 / 0 20 20 0
ALW 47 36 47 35 / 0 20 20 0
PSC 48 34 47 32 / 10 20 10 0
YKM 44 28 46 30 / 10 30 20 0
HRI 49 32 48 31 / 0 20 10 0
ELN 43 30 45 31 / 10 30 20 10
RDM 46 26 50 25 / 0 10 10 0
LGD 40 29 44 27 / 0 20 20 0
GCD 43 27 47 27 / 0 10 10 0
DLS 46 35 48 37 / 10 30 20 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TODAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97
000
FXUS65 KBOI 231726
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1026 AM MST MON NOV 23 2009
.DISCUSSION...NO UPDATES SO FAR. VERY COLD START WILL CHALLENGE HIGH
TEMPERATURES FOR TODAY. SOUNDING GIVES 42 WHICH LOOKS ON TARGET. MAY
NEED AN UPDATE AROUND NOON DEPENDING ON HOW FAST/SLOW SURFACE
INVERSION ERODES. LOOK FOR THE SUBSIDENCE INVERSION /DUE TO
SINKING AND WARMING ALOFT/ TO STRENGTHEN WED/THURS AFTER A WEAK
SYSTEM CROSSES NORTH TUESDAY. THIS COMBINED WITH SNOW MELT LOOKS
TO LEAD TO A MOIST INVERSION THROUGH THANKSGIVING. THERE ARE TWO
MAIN AREAS OF CONCERN SO FAR. EXPECT STRATUS AND FOG DEVELOPING
IN THE UPPER SNAKE PLAIN TO DRIFT WWD INTO THE NW MAGIC VALLEY.
SECOND IS AREAS OF STRATUS AND FOG WHICH ARE EXPECTED TO FORM IN
THE LOWEST ELEVATION OF THE LOWER TREASURE VALLEY. WEDNESDAY LOOKS
TO BE THE MOST INVERTED /GREATEST STRATUS COVERAGE/ DAY AND
STRATUS COULD PERSIST IN THE VALE OREGON TO BLACK CANYON IDAHO
REGION PAST NOON OR EVEN ALL DAY. BY THURSDAY AFTERNOON SE WINDS
SHOULD PICK UP AHEAD OF A COLD FRONT FOR EARLIER BREAKUP.
OF COURSE...ANY STRATUS/FOG HAS NOT FORMED YET AND THAT BRINGS
MUCH MORE THAN NORMAL UNCERTAINTY TO THE SHORTER TERM FORECAST
PERIODS FOR THE TREASURE AND MAGIC VALLEY FORECASTS THROUGH
THURSDAY NIGHT AT LEAST.
MODELS STILL AGREE THAT A FRONT IS DUE ACROSS BOISE AROUND
SUNRISE FRIDAY. HIGH PRESSURE SFC/ALF IS LIKELY TO REBUILD BEHIND
THE FRONT FOR THE REST OF THE UPCOMING THANKSGIVING WEEKEND FOR
INVERTED CONDITIONS. EVEN MORE UNCERTAINTY ON MOIST VS. DRY
INVERSION NEXT WEEKEND DUE TO QUESTIONS ABOUT LOW LEVEL MOISTURE
SOURCES SUCH AS ANY PRECIP WITH FRONT AND LOW/MID ELEVATION SNOW
MELT. WILL IT BE MOIST WITH STRATUS AND FOG OR WILL IT BE DRY WITH
INCREASING HAZE AND DECREASING AIR QUALITY? TOUGH FORECAST
DILEMMA FOR TEMPERATURES BUT MUCH BELOW NORMAL POPS ARE CALLED FOR
EITHER WAY SAT/SUN/MON AS IN CURRENT PACKAGE.
&&
.AVIATION...VFR FOR SW IDAHO AND SE OREGON TODAY. INCREASING
MID-LEVEL CEILINGS TONIGHT OVER THE WEST CENTRAL AND BAKER COUNTY
MTNS WITH WIDELY SCATTERED SNOW SHOWERS AND IFR CONDITIONS ON
TUESDAY. EXPECT LOWER CONDITIONS TO REMAIN NORTH OF KBKE-KMYL LINE.
OTHER STORY WILL BE DEVELOPING INVERSION. EXPECT LOCAL IFR
CONDITIONS TO DEVELOP IN THE LOWER TREASURE VALLEY AND POSSIBLY THE
WESTERN MAGIC VALLEY TUESDAY MORNING. COVERAGE OF IFR CONDITIONS
WILL INCREASE WEDNESDAY MORNING TO POSSIBLY INCLUDE THE BOISE
TERMINAL.
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH TUESDAY...HIGH PRESSURE BUILDING OVER
THE FORECAST AREA FOR BENIGN WEATHER THE NEXT TWO DAYS. HOWEVER...A
WEAK DISTURBANCE IS FORECAST TO SLIDE SOUTHWARD LATE TONIGHT FROM
THE PACIFIC NORTHWEST...EVENTUALLY WASHING OUT OVER CENTRAL IDAHO
WITHIN THE BUILDING UPPER RIDGE. MODELS HANDLING THIS FEATURE
SLIGHTLY DIFFERENTLY WITH THE NAM MORE AGGRESSIVE SHOWING A MORE
SOUTHERLY POSITION AND LIMITED POPS...WHILE THE GFS KEEPS THE
FEATURE NORTH OF OUR FORECAST AREA IN CENTRAL IDAHO ACROSS THE
SALMON RIVER AND POINTS NORTH. HAVE CHOSEN A COMPROMISE BETWEEN THE
TWO AND ALLOWED A SMATTERING OF SLIGHT CHANCE POPS ACROSS BAKER
COUNTY OREGON AND VALLEY COUNTY IDAHO LATE TONIGHT AND TUESDAY.
OTHERWISE...WITH THE ABOVE MENTIONED RIDGE TAKING HOLD...WEATHER
REMAINS QUIET WITH A GOOD AMOUNT OF SUNSHINE TODAY AND PARTLY TO
MOSTLY CLOUDY SKIES TUESDAY. TEMPERATURES COOL TODAY WITH SURFACE
BASED INVERSION STRENGTHENING...BUT WARMING BECOMING MORE
SIGNIFICANT TUESDAY AS HIGH CENTER DRIFTS OVER EASTERN IDAHO
BRINGING EASTERLY COMPONENT FLOW BACK TO OUR REGION AIDING LOW LEVEL
WARMING.
LONG TERM...TUESDAY NIGHT THROUGH MONDAY...THE PATTERN THROUGH THE
PERIOD IS PROGRESSIVE. MODEL AGREEMENT AND RUN TO RUN CONSISTENCY
ARE QUITE GOOD THROUGH FRIDAY. A RIDGE OVER OUR AREA WEDNESDAY MOVES
EAST OF THE ROCKIES THURSDAY FOLLOWED BY A SHORTWAVE TROUGH CROSSING
THE REGION THURSDAY NIGHT THROUGH FRIDAY NIGHT. OVER THE WEEKEND THE
CANADIAN DIVERGES FROM THE GFS40/GFS ENSEMBLE MEAN/ECMWF BY BRINGING
US A MUCH COLDER PATTERN WITH A RIDGE BUILDING OFFSHORE RATHER THAN
OVER THE WEST COAST STATES. WE ARE STAYING WITH THE MILDER
GUIDANCE...WITH TEMPERATURES 5 TO 10 DEGREES ABOVE NORMAL ON
THANKSGIVING DAY...COOLING TO NEAR NORMAL FOR SATURDAY THROUGH
MONDAY. BEST CHANCES OF PRECIPITATION WILL BE WITH THE TROUGH
PASSAGE THURSDAY NIGHT THROUGH FRIDAY NIGHT. FOR THE REST OF THE
PERIOD POPS WILL BE BELOW NORMAL FOR OUR SOUTHERN ZONES AND NEAR
NORMAL FOR BAKER COUNTY AND THE WEST CENTRAL IDAHO MOUNTAINS.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...VM
AVIATION.....DG
PREV SHORT TERM...GS
PREV LONG TERM....JT/MT
000
FXUS66 KMFR 231653
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
850 AM PST MON NOV 23 2009
.DISCUSSION...A WEAK RIDGE IS LOCATED OVER THE REGION. WESTERLY FLOW
WILL ALLOW VARYING AMOUNTS OF HIGH CLOUDS TO MOVE ACROSS THE AREA.
THE MAJOR VALLEYS IN SOUTHWEST OREGON AND NORTHWEST CALIFORNIA HAVE
FOG THIS MORNING...AND WITH THE AIR MASS GRADUALLY BECOMING MORE
STABLE UNDER BUILDING HIGH PRESSURE...THIS COULD BECOME A PERSISTENT
PROBLEM OVER THE NEXT FEW DAYS.
&&
.AVIATION...AREAS OF IFR CONDITIONS DUE TO FOG INTERIOR
VALLEYS...OTHERWISE VFR TODAY.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS
UNTIL 4 PM PST THIS AFTERNOON FOR PZZ350-PZZ356.
HAZARDOUS SEAS WARNING UNTIL 10 AM PST THIS MORNING FOR PZZ370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST
WEDNESDAY FOR PZZ376.
$$
RH
000
FXUS66 KPQR 231638
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
838 AM PST MON NOV 23 2009
.SYNOPSIS...A WEAK WARM FRONT OFF THE COAST WILL SHIFT NORTHEAST
TODAY...THEN A WEAK COLD FRONT WILL SAG SE INTO NW OREGON TONIGHT.
THE FRONT WILL STALL LATE TONIGHT...THEN LIFT NE AS A WARM FRONT ON
TUE. THE NEXT FRONTAL SYSTEM IS NOT EXPECTED TO MOVE IN UNTIL LATE
THURSDAY.
&&
.SHORT TERM...THE MAIN THREAT FOR RAIN THOUGH TODAY SHOULD BE OVER
THE NW PART OF THE FORECAST AREA...WHERE ISENTROPIC LIFT IS BEST
AHEAD OF THE WARM FRONT OFFSHORE.
MODELS INDICATE A COLD FRONT SAGGING DOWN INTO THE REGION LATE TODAY
AND TONIGHT. WILL NEED TO INCLUDE POPS MOST AREAS BY TONIGHT AND
EARLY TUE WITH BAROCLINIC ZONE OVER THE AREA...BUT WITH WEAK DYNAMICS
POPS WILL BE LIMITED TO CHANCE TO LIKELY CATEGORY. FRONT LIFTS BACK
TO THE N LATE TUE AND TUE NIGHT WITH THE UPPER RIDGE
REBOUNDING...RESULTING IN DIMINISHING POPS BY TUE NIGHT...AND A DRY
DAY WED. WOLFE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MODELS IN SOME AGREEMENT ON BRINGING A FRONTAL SYSTEM AND ITS
ASSOCIATED UPPER LEVEL TROF THROUGH THE REGION THU/THU NIGHT FOR A
RETURN TO WET WEATHER. AFTER THIS SYSTEM MOVES THROUGH...THE WEAK
HIGH PRES RIDGE REASSERTS ITSELF OVER THE FORECAST AREA...KEEPING
MOST ENERGY NORTH OF FORECAST AREA. FOG MAY BE MORE OF A PROBLEM IN
THE EXTENDED.
&&
.AVIATION...MUCH MORE TRANQUIL TODAY. PRIMARILY VFR CONDITIONS
ACROSS THE REGION. A WARM FRONT APPROACHING FROM THE WEST WILL
SPREAD AREAS OF MVFR WITH OCCASIONAL RA ALONG THE COAST AROUND 20Z.
MAY SEE SOME SPRINKLES INLAND AS THE WARM FRONT PASSES THROUGH...BUT
REMAINING GENERALLY DRY WITH VFR THROUGH 02Z.
KPDX AND APPROACHES...NO ADVERSE WEATHER IMPACTS EXPECTED. VFR
CONDITIONS TO REMAIN THROUGH 06Z TONIGHT.
&&
.MARINE...LOW PRESSURE IS MOVING INTO VANCOUVER ISLAND THIS
MORNING...PUSHING A WARM FRONT INTO THE WA/OR COASTAL WATERS.
ASSOCIATED COLD FRONT EXTENDS SW FROM LOW AND WILL NOT DIRECTLY MOVE
THROUGH WATERS UNTIL MIDWEEK. WINDS JUST BEHIND WARM FRONT MAY
APPROACH GALE IN A FEW GUSTS...BUT FOR NOW SCA FOR WINDS/SEAS APPEAR
SUFFICIENT. SEAS WILL REMAIN IN THE 10-13 FT RANGE THROUGH TODAY...
BUT MAY FALL BELOW 10 FEET FOR A TIME TONIGHT AND TUE. GENERALLY
TRANQUIL WEATHER THEN EXPECTED INTO WED...THEN THE COLD FRONT WILL
FINALLY SLIDE ACROSS THE COASTAL WATERS WED NIGHT/THU. SOME MODELS
SHOW THE POSSIBILITY OF A STRONG LOW DEVELOPING ALONG THIS FRONT OFF
THE OREGON COAST WED NIGHT OR EARLY THU...WILL NEED TO MONITOR THIS
FOR POTENTIAL GALES DURING THAT TIME PERIOD. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO
FLORENCE OUT 0-60 NM THROUGH TUE.
SMALL CRAFT ADVISORY FOR WINDS CAPE SHOALWATER TO CASCADE
HEAD OUT 0-60 NM AND CASCADE HEAD TO FLORENCE OUT 20-60
NM TODAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR THROUGH
THIS EVENING.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KPDT 231558 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
755 AM PST MON NOV 23 2009
.SHORT TERM...HIGH PRESSURE THAT IS PROVIDING A MOSTLY SUNNY
BEGINNING WILL GIVE WAY TO A DISTURBANCE MOVG INTO THE PACNW THIS
AFTERNOON. THIS SHOULD SPREAD CLOUDS INTO PORTIONS OF THE AREA
ESPECIALLY OVER THE WA CASCADES WHERE A FEW SHOWERS MAY DEVELOP LATE
THIS AFTERNOON AND THEN SPREAD EAST LATER ON. OTHERWISE HIGH TEMPS
SEEM TO BE IN THE BALLPARK AND THE SHORT TERM FORECAST APPEARS ON
TRACK FOR NOW.
&&
.PREVIOUS AVIATION DISCUSSION...12Z TAFS...VFR CONDITIONS WILL
PREVAIL THROUGH THE DAY TODAY WITH MID AND HIGH CLOUDS. ANOTHER
WEATHER DISTURBANCE WILL MOVE INTO THE AREA OVERNIGHT TONIGHT WITH
ANOTHER CHANCE OF RAIN AND MOUNTAIN SNOW. THIS WILL MAINLY AFFECT
NORTHEAST OREGON AND EASTERN WASHINGTON. TAF KRDM IN CENTRAL OREGON
WILL LIKELY NOT SEE ANY PRECIPITATION FROM THIS SYSTEM. THERE MAY BE
BRIEF PERIODS OF MVFR OR EVEN IFR TONIGHT IN RAIN/SNOW
SHOWERS...ESPECIALLY AT KDLS...KYKM AND KPSC...AND TO A LESSER
DEGREE AT KPDT AND KALW. WINDS OF 10 TO 20 KTS THIS MORNING WILL
GRADUALLY CONTINUE TO DECREASE TODAY. THE WIND IS NOT EXPECTED TO
INCREASE MUCH WITH THIS NEXT SYSTEM... BUT PERHAPS 15 TO 25 KTS AT
TIMES...ESPECIALLY NEAR SHOWERS AND WITH THE COLD FRONT PASSAGE. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 47 34 48 33 / 0 20 20 0
ALW 47 36 47 35 / 0 20 20 0
PSC 48 34 47 32 / 10 20 10 0
YKM 44 28 46 30 / 10 30 20 0
HRI 49 32 48 31 / 0 20 10 0
ELN 43 30 45 31 / 10 30 20 10
RDM 46 26 50 25 / 0 10 10 0
LGD 40 29 44 27 / 0 20 20 0
GCD 43 27 47 27 / 0 10 10 0
DLS 46 35 48 37 / 10 30 20 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TODAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97
000
FXUS66 KPDT 231142
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
345 AM PST MON NOV 23 2009
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...A WEAK UPPER RIDGE WILL
BE OVER THE REGION TODAY. THUS SHOULD SEE MOSTLY DRY CONDITIONS WITH
VARIABLE AMOUNTS OF HIGH CLOUDINESS TODAY. THERE WILL BE FEW SHOWERS
DRIFT OVER INTO THE CENTRAL WASHINGTON CASCADE EAST SLOPES FROM
WESTERN WASHINGTON THIS MORNING. A DISTURBANCE IN THE EASTERN GULF
OF ALASKA WILL MOVE TOWARDS NORTHWEST WASHINGTON THIS AFTERNOON.
THIS SYSTEM SHOULD INCREASE CLOUDINESS AND BRING A BETTER CHANCE OF
LIGHT PRECIP TO THE CENTRAL WASHINGTON CASCADE EAST SLOPES THIS
AFTERNOON. THIS DISTURBANCE WILL MOVE EAST ACROSS NORTHERN
WASHINGTON AND SOUTHERN BRITISH COLUMBIA INTO MONTANA TONIGHT AND
TUESDAY. AS A RESULT THERE SHOULD BE VARYING CHANCES OF MOSTLY LIGHT
PRECIP OVER SOUTHEAST WASHINGTON AND NORTHEAST OREGON TONIGHT INTO
TUESDAY. AT THIS TIME EXPECT OUR CENTRAL OREGON ZONES TO STAY DRY.
BY TUESDAY AFTERNOON PRECIP SHOULD BE LIMITED TO LINGERING MOUNTAIN
SHOWERS. ANOTHER UPPER RIDGE LOOKS TO BUILD TUESDAY AFTERNOON AND
TUESDAY NIGHT. THIS RIDGE WOULD PUSH THE MAIN STORM TRACK NORTHWEST
OF OUR REGION WITH ONLY A SLIGHT CHANCE OF VERY LIGHT PRECIP OVER
THE CENTRAL WASHINGTON CASCADE EAST SLOPES. THIS RIDGE LOOKS TO BE
STRONG ENOUGH TO DEVELOP STRONG LOW LEVEL INVERSIONS OVER THE
COLUMBIA BASIN. AS SUCH WILL KEEP SOME MENTION OF PATCHY FOG AND
FREEZING FOG FOR LATE TUESDAY NIGHT BELOW 900 FEET MSL IN THE BASIN
AND COLUMBIA RIVER GORGE. 90
.LONG TERM...WEDNESDAY THROUGH NEXT SUNDAY...HIGH PRESSURE ALOFT
WILL GRADUALLY BUILD STRONGER OVER THE REGION FOR MOST OF THIS WEEK.
A WEAK COLD FRONT WILL CROSS THE REGION ON TUESDAY BUT WILL BE
PUSHED BACK UP NORTH BY THE STRENGTHENING UPPER RIDGE. THIS WILL
KEEP MOISTURE AND PACIFIC WEATHER SYSTEMS MAINLY THE NORTH OF THE
CWA WITH JUST A FEW MID AND HIGH CLOUDS OVER THE FORECAST AREA. THEN
NEXT WEATHER SYSTEM TO AFFECT THE REGION WILL ARRIVE BY THURSDAY
NIGHT AND CONTINUE UNTIL FRIDAY...FIRST AS A WARM FRONT QUICKLY
FOLLOWED BY A COLD FRONT. THIS FEATURE WILL BRING A SMALL AMOUNT OF
PRECIPITATION TO THE AREA AS IT WILL BE MOVING FAST WITH AN UPPER
JET PUSHING IT EASTWARD QUICKLY AND PERPENDICULAR TO THE COLD FRONT.
THIS WILL BE FOLLOWED BY HIGH PRESSURE OVER THE REGION AGAIN FOR
SATURDAY AND SUNDAY. 88
&&
.AVIATION...12Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE DAY
TODAY WITH MID AND HIGH CLOUDS. ANOTHER WEATHER DISTURBANCE WILL
MOVE INTO THE AREA OVERNIGHT TONIGHT WITH ANOTHER CHANCE OF RAIN AND
MOUNTAIN SNOW. THIS WILL MAINLY AFFECT NORTHEAST OREGON AND EASTERN
WASHINGTON. TAF KRDM IN CENTRAL OREGON WILL LIKELY NOT SEE ANY
PRECIPITATION FROM THIS SYSTEM. THERE MAY BE BRIEF PERIODS OF MVFR
OR EVEN IFR TONIGHT IN RAIN/SNOW SHOWERS...ESPECIALLY AT KDLS...KYKM
AND KPSC...AND TO A LESSER DEGREE AT KPDT AND KALW. WINDS OF 10 TO
20 KTS THIS MORNING WILL GRADUALLY CONTINUE TO DECREASE TODAY. THE
WIND IS NOT EXPECTED TO INCREASE MUCH WITH THIS NEXT SYSTEM... BUT
PERHAPS 15 TO 25 KTS AT TIMES...ESPECIALLY NEAR SHOWERS AND WITH THE
COLD FRONT PASSAGE. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 47 34 48 33 / 0 20 20 0
ALW 47 36 47 35 / 0 20 20 0
PSC 48 34 47 32 / 10 20 10 0
YKM 44 28 46 30 / 10 30 20 0
HRI 49 32 48 31 / 0 20 10 0
ELN 43 30 45 31 / 10 30 20 10
RDM 46 26 50 25 / 0 10 10 0
LGD 40 29 44 27 / 0 20 20 0
GCD 43 27 47 27 / 0 10 10 0
DLS 46 35 48 37 / 10 30 20 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TODAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
90/88/88
000
FXUS66 KMFR 231111
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
311 AM PST MON NOV 23 2009
.DISCUSSION...THERE WERE NO DRAMATIC CHANGES IN THE 00Z RUN OF
MODEL DATA. HIGH PRESSURE WILL BUILD OVER THE CALIFORNIA OFFSHORE
WATERS TODAY INTO WEDNESDAY...PUSHING THE STORM TRACK NORTHWARD.
THE MAIN CHANGES TO THE FORECAST WERE TO ADJUST TEMPERATURES TO
MORE PRECISELY REFLECT THE EFFECTS OF NIGHT AND MORNING VALLEY LOW
CLOUDS AND FOG...WHICH ARE EXPECTED FOR MUCH OF THE NEXT WEEK
UNDER A BUILDING HIGH PRESSURE RIDGE.
THE ONE VERY NOTABLE EXCEPTION IS A WEAK TO MODERATE COLD
FRONT...STILL INDICATED BY BOTH THE GFS AND ECMWF MODELS TO REACH
THE COAST IN THE AFTERNOON ON THANKSGIVING DAY AND MORE RATHER
SLOWLY EAST WITH ANY INLAND IMPACTS TO TRAVEL PRIMARILY LATE
THURSDAY EVENING INTO FRIDAY MORNING. SNOW LEVELS STILL LOOK TO BE
AROUND 5500 TO 6000 FEET WHEN PRECIPITATION IS LIKELY TO BEGIN
THEN GRADUALLY FALL TO 3500 TO 4000 FEET BY SUNRISE ON FRIDAY. THE
ECMWF IS WEAKER/LESS AMPLIFIED WITH THE TROUGH AND WOULD KEEP THE
BULK OF PRECIPITATION FROM SOUTHWEST OREGON NORTHWARD. THE ECMWF
HAS DONE BETTER WITH THE LAST TWO SYSTEMS AND IS FAVORED. BUT...I
WILL STILL INCLUDE A HEDGE TOWARD THE GFS SOLUTION WITH LIKELY
POPS FOR SISKIYOU COUNTY AND A CHANCE OF PRECIPITATION FOR AREAS
EAST OF THE CASCADES. THIS SCENARIO WOULD RESULT IN SNOWFALL
AMOUNTS GENERALLY BETWEEN 1 AND 5 INCHES WITH THE MOST IN THE
VICINITY OF CRATER LAKE. ISOLATED TO SCATTERED SHOWERS ARE
EXPECTED TO GRADUALLY TAPER OFF FRIDAY AFTERNOON INTO THE EVENING.
HIGH PRESSURE IS EXPECTED TO RETURN NEXT WEEKEND AND PERSIST INTO
MONDAY.
&&
.AVIATION...IFR CONDITIONS ARE WIDESPREAD IN THE UMPQUA BASIN AND
PATCHY ELSEWHERE...INCLUDING WESTERN SISKIYOU COUNTY AND MODOC
COUNTY. IFR IS EXPECTED TO DEVELOP SHORTLY IN THE ROGUE VALLEY.
CONDITIONS WILL IMPROVE LATE THIS MORNING. OTHERWISE...VFR
CONDITIONS WILL PREVAIL. VALLEY LOW CLOUDS AND FOG WILL DEVELOP
AGAIN TONIGHT.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS
UNTIL 4 PM PST THIS AFTERNOON FOR PZZ350-PZZ356.
HAZARDOUS SEAS WARNING UNTIL 10 AM PST THIS MORNING FOR PZZ370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST WEDNESDAY
FOR PZZ376.
$$
DW
000
FXUS66 KPDT 231054
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
253 AM PST MON NOV 23 2009
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...A WEAK UPPER RIDGE WILL
BE OVER THE REGION TODAY. THUS SHOULD SEE MOSTLY DRY CONDITIONS WITH
VARIABLE AMOUNTS OF HIGH CLOUDINESS TODAY. THERE WILL BE FEW SHOWERS
DRIFT OVER INTO THE CENTRAL WASHINGTON CASCADE EAST SLOPES FROM
WESTERN WASHINGTON THIS MORNING. A DISTURBANCE IN THE EASTERN GULF
OF ALASKA WILL MOVE TOWARDS NORTHWEST WASHINGTON THIS AFTERNOON.
THIS SYSTEM SHOULD INCREASE CLOUDINESS AND BRING A BETTER CHANCE OF
LIGHT PRECIP TO THE CENTRAL WASHINGTON CASCADE EAST SLOPES THIS
AFTERNOON. THIS DISTURBANCE WILL MOVE EAST ACROSS NORTHERN
WASHINGTON AND SOUTHERN BRITISH COLUMBIA INTO MONTANA TONIGHT AND
TUESDAY. AS A RESULT THERE SHOULD BE VARYING CHANCES OF MOSTLY LIGHT
PRECIP OVER SOUTHEAST WASHINGTON AND NORTHEAST OREGON TONIGHT INTO
TUESDAY. AT THIS TIME EXPECT OUR CENTRAL OREGON ZONES TO STAY DRY.
BY TUESDAY AFTERNOON PRECIP SHOULD BE LIMITED TO LINGERING MOUNTAIN
SHOWERS. ANOTHER UPPER RIDGE LOOKS TO BUILD TUESDAY AFTERNOON AND
TUESDAY NIGHT. THIS RIDGE WOULD PUSH THE MAIN STORM TRACK NORTHWEST
OF OUR REGION WITH ONLY A SLIGHT CHANCE OF VERY LIGHT PRECIP OVER
THE CENTRAL WASHINGTON CASCADE EAST SLOPES. THIS RIDGE LOOKS TO BE
STRONG ENOUGH TO DEVELOP STRONG LOW LEVEL INVERSIONS OVER THE
COLUMBIA BASIN. AS SUCH WILL KEEP SOME MENTION OF PATCHY FOG AND
FREEZING FOG FOR LATE TUESDAY NIGHT BELOW 900 FEET MSL IN THE BASIN
AND COLUMBIA RIVER GORGE. 90
.LONG TERM...WEDNESDAY THROUGH NEXT SUNDAY...HIGH PRESSURE ALOFT
WILL GRADUALLY BUILD STRONGER OVER THE REGION FOR MOST OF THIS WEEK.
A WEAK COLD FRONT WILL CROSS THE REGION ON TUESDAY BUT WILL BE
PUSHED BACK UP NORTH BY THE STRENGTHENING UPPER RIDGE. THIS WILL
KEEP MOISTURE AND PACIFIC WEATHER SYSTEMS MAINLY THE NORTH OF THE
CWA WITH JUST A FEW MID AND HIGH CLOUDS OVER THE FORECAST AREA. THEN
NEXT WEATHER SYSTEM TO AFFECT THE REGION WILL ARRIVE BY THURSDAY
NIGHT AND CONTINUE UNTIL FRIDAY...FIRST AS A WARM FRONT QUICKLY
FOLLOWED BY A COLD FRONT. THIS FEATURE WILL BRING A SMALL AMOUNT OF
PRECIPITATION TO THE AREA AS IT WILL BE MOVING FAST WITH AN UPPER
JET PUSHING IT EASTWARD QUICKLY AND PERPENDICULAR TO THE COLD FRONT.
THIS WILL BE FOLLOWED BY HIGH PRESSURE OVER THE REGION AGAIN FOR
SATURDAY AND SUNDAY. 88
&&
.AVIATION...PREVIOUS DISCUSSION...06Z TAFS...VFR CONDITIONS ARE
EXPECTED FOR THE NEXT 24 HOURS. SKIES WILL REMAIN SCT-BKN ABOVE
7000-10000 FT AGL THROUGH TOMORROW AFTERNOON. THE NEXT WEATHER
SYSTEM WILL APPROACH AFTER 23/20Z AND SKIES WILL BECOME BKN-OVC
ABOVE 5000 FT AGL. A FEW RAIN SHOWERS WILL DEVELOP IN AND NEAR THE
CASCADES AFTER 24/00Z AFFECTING KYKM AND KDLS. SURFACE WINDS AT
KPSC...KALW AND KPDT WILL BE AT 10 TO 20 KTS WITH GUSTS TO 30 KTS
THROUGH 23/12Z THEN DECREASE TO BELOW 15 KTS THROUGH TOMORROW
EVENING. OTHER TAF LOCATIONS WILL REMAIN BELOW 15 KTS THROUGH THE
NEXT 24 HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 47 34 48 33 / 0 20 20 0
ALW 47 36 47 35 / 0 20 20 0
PSC 48 34 47 32 / 10 20 10 0
YKM 44 28 46 30 / 10 30 20 0
HRI 49 32 48 31 / 0 20 10 0
ELN 43 30 45 31 / 10 30 20 10
RDM 46 26 50 25 / 0 10 10 0
LGD 40 29 44 27 / 0 20 20 0
GCD 43 27 47 27 / 0 10 10 0
DLS 46 35 48 37 / 10 30 20 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TODAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
90/88/88
000
FXUS66 KPQR 231032
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
232 AM PST MON NOV 23 2009
.SYNOPSIS...A WEAK WARM FRONT OFF THE COAST WILL SHIFT NORTHEAST
TODAY...THEN A WEAK COLD FRONT WILL SAG SE INTO NW OREGON TONIGHT.
THE FRONT WILL STALL LATE TONIGHT...THEN LIFT NE AS A WARM FRONT ON
TUE. THE NEXT FRONTAL SYSTEM IS NOT EXPECTED TO MOVE IN UNTIL LATE
THURSDAY.
&&
.SHORT TERM...RADAR SHOWS SOME LIGHT PRECIPITATION HAS DEVELOPED
OVER THE S WA FOOTHILLS EARLY THIS MORNING...LIKELY AS THE RESULT OF
LOW LEVEL WARM AIR ADVECTION AND OROGRAPHICS. THE MAIN THREAT FOR
RAIN THOUGH TODAY SHOULD BE OVER THE NW PART OF THE FORECAST AREA
THOUGH...WHERE ISENTROPIC LIFT IS BEST AHEAD OF THE WARM FRONT
OFFSHORE.
WITH A SHORTWAVE CROSSING OVER THE TOP OF THE RIDGE THROUGH SOUTHERN
BC LATE TODAY AND TONIGHT...MODELS INDICATE A COLD FRONT SAGGING
DOWN INTO THE REGION LATE TODAY AND TONIGHT. WILL NEED TO INCLUDE
POPS MOST AREAS BY TONIGHT AND EARLY TUE WITH BAROCLINIC ZONE OVER
THE AREA...BUT WITH WEAK DYNAMICS POPS WILL BE LIMITED TO CHANCE TO
LIKELY CATEGORY. FRONT LIFTS BACK TO THE N LATE TUE AND TUE NIGHT
WITH THE UPPER RIDGE REBOUNDING...RESULTING IN DIMINISHING POPS BY
TUE NIGHT...AND A DRY DAY WED.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MODELS IN SOME AGREEMENT ON BRINGING A FRONTAL SYSTEM AND ITS
ASSOCIATED UPPER LEVEL TROF THROUGH THE REGION THU/THU NIGHT FOR A
RETURN TO WET WEATHER. AFTER THIS SYSTEM MOVES THROUGH...THE WEAK
HIGH PRES RIDGE REASSERTS ITSELF OVER THE FORECAST AREA...KEEPING
MOST ENERGY NORTH OF FORECAST AREA.
&&
.AVIATION...MUCH MORE TRANQUIL THIS AM. VFR CONDITIOSN ACROSS THE
REGION...AND THIS WILL CHANGE LITTLE TODAY. WITH BREAKS IN THE
CIGS...AND LIGHT WINDS...COULD SEE PATCHY FOG SOUTH OF SALEM THROUGH
17Z. A WARM FRONT APPROACHING FROM THE SW WILL SPREAD AREAS OF MVFR
WITH OCCASIONAL RA ALONG THE COAST AFTER 20Z. REMAINING GENERALLY
DRY WITH VFR INLAND THROUGH 02Z.
KPDX AND APPROACHES...NO ADVERSE WEATHER IMPACTS EXPECTED. VFR
CONDITIONS TO REMAIN THROUGH 06Z TONIGHT.
&&
.MARINE...SEAS STILL IN THE 11 TO 14 FT RANGE. BUT THESE WILLL
CONTINUE TO SUBSIDE A BIT TODAY...BUT WILL REMAIN ABOVE 10 FT
THROUGH TUE. BREEZY CONDITIONS EXPECTED TODAY AND TONIGHT AS WARM
FRONT LIFTS ACROSS THE COASTAL WATERS. DONT SEE ENOUGH SUPPORT FOR
GALE FORCE WINDS...SO WILL CANCEL GALE AND JUST KEEP AT SMALL CRAFT
ADVISORY TODAY INTO EARLY EVENING.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO
FLORENCE THROUGH TUE.
SMALL CRAFT ADVISORY FOR WINDS CAPE SHOALWATER TO CASCADE
HEAD TODAY.
SMALL CRAFT ADVISORY FOR WINDS FROM CASCADE HEAD TO FLORENCE
THIS AFTERNOON.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KPQR 231031
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
848 PM PST SUN NOV 22 2009
.SYNOPSIS...A WEAK WARM FRONT OFF THE COAST WILL SHIFT NORTHEAST
TODAY...THEN A WEAK COLD FRONT WILL SAG SE INTO NW OREGON TONIGHT.
THE FRONT WILL STALL LATE TONIGHT...THEN LIFT NE AS A WARM FRONT ON
TUE. THE NEXT FRONTAL SYSTEM IS NOT EXPECTED TO MOVE IN UNTIL LATE
THURSDAY.
&&
.SHORT TERM...RADAR SHOWS SOME LIGHT PRECIPITATION HAS DEVELOPED
OVER THE S WA FOOTHILLS EARLY THIS MORNING...LIKELY AS THE RESULT OF
LOW LEVEL WARM AIR ADVECTION AND OROGRAPHICS. THE MAIN THREAT FOR
RAIN THOUGH TODAY SHOULD BE OVER THE NW PART OF THE FORECAST AREA
THOUGH...WHERE ISENTROPIC LIFT IS BEST AHEAD OF THE WARM FRONT
OFFSHORE.
WITH A SHORTWAVE CROSSING OVER THE TOP OF THE RIDGE THROUGH SOUTHERN
BC LATE TODAY AND TONIGHT...MODELS INDICATE A COLD FRONT SAGGING
DOWN INTO THE REGION LATE TODAY AND TONIGHT. WILL NEED TO INCLUDE
POPS MOST AREAS BY TONIGHT AND EARLY TUE WITH BAROCLINIC ZONE OVER
THE AREA...BUT WITH WEAK DYNAMICS POPS WILL BE LIMITED TO CHANCE TO
LIKELY CATEGORY. FRONT LIFTS BACK TO THE N LATE TUE AND TUE NIGHT
WITH THE UPPER RIDGE REBOUNDING...RESULTING IN DIMINISHING POPS BY
TUE NIGHT...AND A DRY DAY WED.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MODELS IN SOME AGREEMENT ON BRINGING A FRONTAL SYSTEM AND ITS
ASSOCIATED UPPER LEVEL TROF THROUGH THE REGION THU/THU NIGHT FOR A
RETURN TO WET WEATHER. AFTER THIS SYSTEM MOVES THROUGH...THE WEAK
HIGH PRES RIDGE REASSERTS ITSELF OVER THE FORECAST AREA...KEEPING
MOST ENERGY NORTH OF FORECAST AREA.
&&
.AVIATION...MUCH MORE TRANQUIL THIS AM. VFR CONDITIOSN ACROSS THE
REGION...AND THIS WILL CHANGE LITTLE TODAY. WITH BREAKS IN THE
CIGS...AND LIGHT WINDS...COULD SEE PATCHY FOG SOUTH OF SALEM THROUGH
17Z. A WARM FRONT APPROACHING FROM THE SW WILL SPREAD AREAS OF MVFR
WITH OCCASIONAL RA ALONG THE COAST AFTER 20Z. REMAINING GENERALLY
DRY WITH VFR INLAND THROUGH 02Z.
KPDX AND APPROACHES...NO ADVERSE WEATHER IMPACTS EXPECTED. VFR
CONDITIONS TO REMAIN THROUGH 06Z TONIGHT.
&&
.MARINE...SEAS STILL IN THE 11 TO 14 FT RANGE. BUT THESE WILLL
CONTINUE TO SUBSIDE A BIT TODAY...BUT WILL REMAIN ABOVE 10 FT
THROUGH TUE. BREEZY CONDITIONS EXPECTED TODAY AND TONIGHT AS WARM
FRONT LIFTS ACROSS THE COASTAL WATERS. DONT SEE ENOUGH SUPPORT FOR
GALE FORCE WINDS...SO WILL CANCEL GALE AND JUST KEEP AT SMALL CRAFT
ADVISORY TODAY INTO EARLY EVENING.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO
FLORENCE THROUGH TUE.
SMALL CRAFT ADVISORY FOR WINDS CAPE SHOALWATER TO CASCADE
HEAD TODAY.
SMALL CRAFT ADVISORY FOR WINDS FROM CASCADE HEAD TO FLORENCE
THIS AFTERNOON.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS65 KBOI 230949
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
250 AM MST MON NOV 23 2009
.SHORT TERM...TODAY THROUGH TUESDAY...HIGH PRESSURE BUILDING OVER
THE FORECAST AREA FOR BENIGN WEATHER THE NEXT TWO DAYS. HOWEVER...A
WEAK DISTURBANCE IS FORECAST TO SLIDE SOUTHWARD LATE TONIGHT FROM
THE PACIFIC NORTHWEST...EVENTUALLY WASHING OUT OVER CENTRAL IDAHO
WITHIN THE BUILDING UPPER RIDGE. MODELS HANDLING THIS FEATURE
SLIGHTLY DIFFERENTLY WITH THE NAM MORE AGGRESSIVE SHOWING A MORE
SOUTHERLY POSITION AND LIMITED POPS...WHILE THE GFS KEEPS THE
FEATURE NORTH OF OUR FORECAST AREA IN CENTRAL IDAHO ACROSS THE
SALMON RIVER AND POINTS NORTH. HAVE CHOSEN A COMPROMISE BETWEEN THE
TWO AND ALLOWED A SMATTERING OF SLIGHT CHANCE POPS ACROSS BAKER
COUNTY OREGON AND VALLEY COUNTY IDAHO LATE TONIGHT AND TUESDAY.
OTHERWISE...WITH THE ABOVE MENTIONED RIDGE TAKING HOLD...WEATHER
REMAINS QUIET WITH A GOOD AMOUNT OF SUNSHINE TODAY AND PARTLY TO
MOSTLY CLOUDY SKIES TUESDAY. TEMPERATURES COOL TODAY WITH SURFACE
BASED INVERSION STRENGTHENING...BUT WARMING BECOMING MORE
SIGNIFICANT TUESDAY AS HIGH CENTER DRIFTS OVER EASTERN IDAHO
BRINGING EASTERLY COMPONENT FLOW BACK TO OUR REGION AIDING LOW LEVEL
WARMING.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY...THE PATTERN THROUGH THE
PERIOD IS PROGRESSIVE. MODEL AGREEMENT AND RUN TO RUN CONSISTENCY
ARE QUITE GOOD THROUGH FRIDAY. A RIDGE OVER OUR AREA WEDNESDAY MOVES
EAST OF THE ROCKIES THURSDAY FOLLOWED BY A SHORTWAVE TROUGH CROSSING
THE REGION THURSDAY NIGHT THROUGH FRIDAY NIGHT. OVER THE WEEKEND THE
CANADIAN DIVERGES FROM THE GFS40/GFS ENSEMBLE MEAN/ECMWF BY BRINGING
US A MUCH COLDER PATTERN WITH A RIDGE BUILDING OFFSHORE RATHER THAN
OVER THE WEST COAST STATES. WE ARE STAYING WITH THE MILDER
GUIDANCE...WITH TEMPERATURES 5 TO 10 DEGREES ABOVE NORMAL ON
THANKSGIVING DAY...COOLING TO NEAR NORMAL FOR SATURDAY THROUGH
MONDAY. BEST CHANCES OF PRECIPITATION WILL BE WITH THE TROUGH
PASSAGE THURSDAY NIGHT THROUGH FRIDAY NIGHT. FOR THE REST OF THE
PERIOD POPS WILL BE BELOW NORMAL FOR OUR SOUTHERN ZONES AND NEAR
NORMAL FOR BAKER COUNTY AND THE WEST CENTRAL IDAHO MOUNTAINS.
&&
.AVIATION...LOCAL MVFR CEILINGS AND AREAS OF TERRAIN OBSCURATION
WILL PERSIST IN THE WEST CENTRAL IDAHO MOUNTAINS THROUGH THIS
MORNING. OTHERWISE EXPECT VFR CONDITIONS TODAY THROUGH TUESDAY.
WITH AN INVERSION INTENSIFYING TONIGHT THROUGH WEDNESDAY...PATCHY
NIGHT AND MORNING FOG WILL BE POSSIBLE IN MOUNTAIN VALLEYS...
ESPECIALLY LATE TUESDAY NIGHT AND WEDNESDAY MORNING. SURFACE WINDS
WILL BE LIGHT TODAY. WINDS ALOFT WILL BE LIGHT TO MODERATE
NORTHWEST.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
SHORT TERM...GS
LONG TERM....JT/MT
AVIATION.....JT
000
FXUS66 KPDT 230534 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
933 PM PST SUN NOV 22 2009
UPDATED AVIATION DISCUSSION.
.UPDATE...UPPER LEVEL LOW HAS MOVED INTO WESTERN MONTANA THIS
EVENING AND ACTIVE WEATHER HAS BEEN STEADILY WINDING DOWN. RADAR
STILL SHOWS A FEW LIGHT SNOW SHOWERS IN THE EASTERN MOUNTAINS BUT
INTENSITY IS MUCH REDUCED IN THE LAST FEW HOURS. HAVE ALREADY
ALLOWED WINTER STORM WARNING FOR THE NORTHERN BLUE MOUNTAINS TO
EXPIRE ON SCHEDULE. PRESSURE GRADIENTS HAVE RELAXED CONSIDERABLY IN
THE LAST SEVERAL HOURS AND WINDS HAVE ALSO BEEN DYING DOWN. HAVE
ALLOWED WIND ADVISORY FOR THE BLUE MOUNTAIN FOOTHILLS OF OREGON TO
EXPIRE EARLIER THIS EVENING. WINDS ARE GENERALLY IN THE 10 TO 20 MPH
RANGE WITH A FEW GUSTS TO 25 OR 30 MPH. HAVE UPDATED WINDS THE REST
OF THE NIGHT TO REFLECT THE WINDS DROPPING OFF FASTER THAN FORECAST.
HAVE ALSO MADE A FEW ADJUSTMENTS TO POPS. TEMPERATURES LOOK GOOD.
UPDATE OUT SHORTLY. PERRY
&&
AVIATION...06Z TAFS...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24
HOURS. SKIES WILL REMAIN SCT-BKN ABOVE 7000-10000 FT AGL THROUGH
TOMORROW AFTERNOON. THE NEXT WEATHER SYSTEM WILL APPROACH AFTER
23/20Z AND SKIES WILL BECOME BKN-OVC ABOVE 5000 FT AGL. A FEW RAIN
SHOWERS WILL DEVELOP IN AND NEAR THE CASCADES AFTER 24/00Z AFFECTING
KYKM AND KDLS. SURFACE WINDS AT KPSC...KALW AND KPDT WILL BE AT 10
TO 20 KTS WITH GUSTS TO 30 KTS THROUGH 23/12Z THEN DECREASE TO BELOW
15 KTS THROUGH TOMORROW EVENING. OTHER TAF LOCATIONS WILL REMAIN
BELOW 15 KTS THROUGH THE NEXT 24 HOURS. PERRY
&&
.PREV DISCUSSION... /ISSUED 302 PM PST SUN NOV 22 2009/
SHORT TERM...TONIGHT THROUGH TUESDAY...UPPER LEVEL LOW CENTER OVER
NORTHEAST WASHINGTON AT THIS HOUR WITH SURFACE LOW TRAILING SLIGHTLY
BEHIND ACROSS NORTH CENTRAL WASHINGTON. HAVE SEEN WIDESPREAD
ADVISORY WINDS TODAY WITH LOCALLY STRONGER GUSTS NEARING 60 MPH
NOTED JUST TODAY. OTHER STRONG WINDS HAVE BEEN REPORTED ALONG WITH
SOME DOWNED TREES AS WELL. REFER TO LOCAL STORM REPORTS FOR FURTHER
DETAILS. MANY WIND ADVISORIES AND WINTER WEATHER ADVISORIES WILL BE
ALLOWED TO EXPIRE AT 4 PM AS PLANNED WITH THE WIND ADVISORIES ALONG
THE FOOTHILLS AND THE WINTER WEATHER STATEMENTS FOR THE BLUE
MOUNTAINS LIKELY TO CONTINUE THROUGH THEIR PLANNED EXPIRATION OF 7
PM TONIGHT. SINCE THE PAIR OF LOW CIRCULATIONS HAVE PROGRESSED
SLIGHTLY FURTHER NORTH THAN EXPECTED, SNOW AMOUNTS OVER THE BLUE
MOUNTAINS HAVE BEEN ON THE LIGHT SIDE, BUT ACCUMULATION RATES HAVE
PICKED UP OVER THE LAST FEW HOURS, THUS WILL WAIT AND SEE.
WINDS AND PRECIPITATION WILL CONTINUE TO DECREASE ACROSS THE REGION
AS THE SYSTEM MOVES FURTHER EAST. EXPECT SOME LIGHT SNOW SHOWERS
WILL CONTINUE OVERNIGHT NEAR THE CASCADE CREST AND OVER THE
NORTHEASTERN MOUNTAINS BUT ACCUMULATIONS SHOULD BE FAIRLY LIGHT.
MONDAY WILL BE A RELATIVELY CALM DAY AS FLAT HIGH PRESSURE
CROSSES OVER THE REGION. THE SOUTHERN EDGE OF A COLD FRONT WILL CLIP
THE NORTHEASTERN THIRD OF THE CWA MONDAY NIGHT AND TUESDAY POSSIBLY
BRINGING ANOTHER COUPLE INCHES OF SNOW TO THE WASHINGTON CASCADE
EAST SLOPES AND NORTHEASTERN MOUNTAINS. THAT REALLY SEEMS TO BE THE
ONLY IMPACT THOUGH. IT APPEARS MOST OF THE REGION IS UNDER THE
CASCADE SHADOW INFLUENCE AND WILL REMAIN DRY. TEMPERATURES WILL
GENERALLY REMAIN ON THE COOLER SIDE AS WELL. /JBONK
LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...AN UPPER RIDGE WILL
BUILD OVER EASTERN WASHINGTON AND OREGON TUESDAY NIGHT. SUBSIDENCE
FROM THE RIDGE WILL WILL PROVIDE CLEARING SKIES AND LIGHT WINDS
WITH STRONG SURFACE INVERSIONS TUESDAY NIGHT. IN THE LOWER COLUMBIA
BASIN PATCHY FOG AND FREEZING FOG WILL FORM AT NIGHT UNDER THE
INVERSIONS AND KEEP DAYTIME TEMPERATURES WEDNESDAY BELOW NORMAL. THE
FOG WILL FORM MAINLY ALONG THE LARGE RIVERS AND STREAMS AND THEN
GRADUALLY EXPAND IN COVERAGE WEDNESDAY NIGHT AND THURSDAY. AT HIGHER
ELEVATIONS THE SURFACE INVERSIONS WILL BREAK DURING THE DAY AND
WARMER AIR ALOFT ASSOCIATED WITH THE RIDGE WILL REACH THE SURFACE TO
PRODUCE LARGE DIURNAL TEMPERATURE SPREADS. A COLD FRONT WILL MOVE
INLAND THURSDAY AFTERNOON AND BRING ANOTHER ROUND OF PRECIPITATION
TO THE FORECAST AREA THURSDAY NIGHT AND FRIDAY. MORE SYSTEMS WILL
MOVE THROUGH SATURDAY AND SUNDAY. COONFIELD
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 32 46 37 41 / 10 10 20 10
ALW 34 47 36 42 / 10 10 20 10
PSC 29 45 35 45 / 10 10 10 10
YKM 24 42 31 49 / 10 10 20 10
HRI 28 45 32 45 / 10 10 10 10
ELN 27 40 27 40 / 10 10 30 10
RDM 20 46 25 47 / 10 10 10 10
LGD 25 40 30 42 / 20 10 20 20
GCD 21 44 25 52 / 10 10 10 10
DLS 33 45 35 49 / 20 10 40 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
MONDAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/76/83
000
FXUS66 KPQR 230449
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
848 PM PST SUN NOV 22 2009
.SYNOPSIS...ISOLATED SHOWERS WILL CONTINUE TO DECREASE TONIGHT AS
A WEAK UPPER RIDGE SHIFTS INTO OREGON. A WEAK WARM FRONT OFF THE
COAST WILL SHIFT NORTHEAST ON MONDAY...THEN STALL OVER THE REGION ON
TUESDAY. THE FRONT WILL FINALLY LIFT NORTH INTO WASHINGTON ON
WEDNESDAY...BEFORE A COLD FRONT PUSHES SOUTHEAST INTO THE REGION LATE
THURSDAY.
&&
.SHORT TERM...SATELLITE IMAGERY AND METARS SHOW THE CLOUDS BREAKING
UP OVER THE VALLEYS THIS EVENING...WHILE WEAKENING ONSHORE FLOW IS
STILL ALLOWING SOME SHOWERS OVER THE MOUNTAINS. HOWEVER SATELLITE AND
MODELS SUGGEST MID LEVEL CLOUDS AHEAD OF A WEAK WARM FRONT WILL
ADVECT INTO THE REGION OVERNIGHT...BUT MODELS SHOWING NO QPF EXCEPT
FOR A LITTLE RESIDUAL PRECIP OVER THE NORTHERN MOUNTAINS...AS WEAK
SUBSIDENCE DEVELOPS AS A PRECURSOR UPPER RIDGE SHIFTS INLAND. ADDED
SOME PATCHY VALLEY FOG FOR EARLY MON BUT THIS MIGHT NOT MATERIALIZE
IF THE MID LEVEL CLOUDS ARE THICK ENOUGH. RW
REMAINDER OF SHORT TERM UNCHANGED...
AN AREA OF WARM AIR ADVECTION SETS UP OVER THE NW PART OF THE
FORECAST AREA MON...AND CONTINUES INTO TUE. A WEAK SHORTWAVE MOVES
ACROSS THE TOP OF THE DEVELOPING UPPER RIDGE TUE...BRINGING THE BEST
CHANCE FOR OVERRUNNING PRECIPITATION TO THE NW PART OF THE AREA ON
MON NIGHT WITH THE SHORT WAVE MOVING THROUGH THE FORECAST AREA
WEDNESDAY.
.LONG TERM...MODELS IN SOME AGREEMENT ON BRINGING A FRONTAL SYSTEM
AND ITS ASSOCIATED UPPER LEVEL TROF THROUGH THE REGION THU/THU NIGHT
FOR A RETURN TO WET WEATHER. AFTER THIS SYSTEM MOVES THROUGH...THE
WEAK HIGH PRES RIDGE REASSERTS ITSELF OVER THE FORECAST
AREA...KEEPING MOST ENERGY NORTH OF FORECAST AREA.
&&
.AVIATION...CLOUDS AND SHOWERS CONTINUE TO DECREASE THIS EVENING AS
HIGH PRESSURE BUILDS OVERHEAD. DESPITE RELATIVELY STRONG GRADIENTS
THIS EVENING WINDS ACROSS MOST AREAS ARE CALM. WITH RECENT RAINS AND
CLEARING SKIES AREAS OF IFR FOG MAY FORM IN FAVORED AREAS SUCH AS
HILLSBORO AND THE SOUTH WILLAMETTE VALLEY AFTER 09Z...OTHERWISE
EXPECT VFR CONDITIONS. THE NEXT SYSTEM WILL BEGIN TO MOVE IN MONDAY
AFTERNOON WITH RAIN STARTING IN THE AFTERNOON ON THE COAST.
KPDX AND APPROACHES...VFR CONDITIONS EXPECTED TONIGHT. HOWEVER...
THERE IS A 30% CHANCE OF IFR FOG OR STRATUS BETWEEN 10Z AND 18Z.
&&
.MARINE...LIGHT WINDS WILL CONTINUE TONIGHT. WINDS WILL INCREASE TO
GALE FORCE BY LATE MONDAY MORNING ACROSS THE NORTHERN WATERS AND
SMALL CRAFT ACROSS THE SOUTHERN WATERS. SEAS AT 15-18 FT THIS EVENING
WILL DROP TONIGHT TO NEAR 11 FT BEFORE BUILDING BACK INTO THE MID
TEENS ON MONDAY EVENING.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO
FLORENCE THROUGH MONDAY MORNING.
SMALL CRAFT ADVISORY FOR WINDS CAPE SHOALWATER TO
CASCADE HEAD MONDAY MORNING.
SMALL CRAFT ADVISORY FOR WINDS CASCADE HEAD TO FLORENCE
MONDAY AND MONDAY EVENING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS
THROUGH MON NIGHT.
GALE WARNING FROM CAPE SHOALWATER TO CASCADE HEAD MONDAY
THROUGH EARLY MONDAY EVENING.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KMFR 230446
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
850 PM PST SUN NOV 22 2009
.DISCUSSION...HIGH PRESSURE ALOFT IS BUILDING BRINGING INCREASING
STABILITY OVER THE REGION. ALL SHOWERS HAVE ENDING IN OUR REGION.
LIGHT WINDS...LONG NIGHTS...SURFACE HIGH PRESSURE AND RECENT RAIN
AND SNOWFALL IS A PERFECT SCENARIO FOR FOG DEVELOPING IN THE VALLEYS
IN THE WEST AND EAST SIDE. MONDAY THROUGH WEDNESDAY WILL FEATURE FOG
FORMING AFTER MIDNIGHT IN FAVORED VALLEYS. THE FOG WILL LIFT TO LOW
CLOUDS AND EVENTUALLY CLEAR AROUND NOON IN MOST LOCATIONS. TUESDAY A
WEAK COLD FRONT BRUSHES THE COASTAL ZONES...BUT RAIN CHANCES ARE
VERY LOW. CLEARING TIME WILL DICTATE HOW WARM TEMPERATURES GET
DURING THE FIRST HALF OF THE WEEK. CURRENT FORECAST PRESENTS THE
IDEA THAT WEDNESDAY WILL BE THE WARMEST DAY AS GFS AND NAM AGREE
THAT AIRMASS MAY BE 1-2 STANDARD DEVIATIONS ABOVE AVERAGE BY THAT
TIME. CLOUDS WILL BE MOSTLY OF THE MID AND HIGH VARIETY THIS WEEK.
WEATHER FOR THANKSGIVING DAY TRAVEL IS GRADUALLY COMING INTO
FOCUS. GFS ENSEMBLE MEMBERS ALL INDICATE A SIMILAR IDEA OF AN
UPPER TROUGH AND COLD FRONT AFFECTING NORTHERN CALIFORNIA AND
OREGON BY THURSDAY AFTERNOON. SNOW LEVELS WILL INITIALLY BE
BETWEEN 5000 TO 7000 FEET BUT WILL FALL THURSDAY NIGHT AND END UP
AROUND 3500 FEET FRIDAY MORNING. THE ECMWF INDICATES MORE MOISTURE
THAN THE GFS SO WILL NEED TO MONITOR TRENDS IN THE NEAR-TERM.
SISKIYOU PASS WILL NOT LIKELY HAVE SIGNIFICANT SNOW IMPACTS WITH
THIS WEATHER SYSTEM. HOWEVER...AS COLD AIR FOLLOWS THE COLD
FRONT...SOME SNOW MAY ACCUMULATE AT PASS LEVEL LATE THURSDAY NIGHT
OR EARLY FRIDAY MORNING.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE AT ALL TAF
SITES THROUGH LATE TONIGHT WHEN FOG FORMS AT RBG AND
MFR...RESULTING IN IFR CONDITIONS THAT SHOULD LAST THROUGH MIDDAY
MONDAY. MOUNTAIN OBSCURATION WILL CONTINUE TO IMPACT MOST OF THE
HIGH TERRAIN THROUGH ABOUT 06Z WHEN DRY AIR BEGINS TO FILTER INTO
THE ELEVATED AREAS AND CLOUDS THERE DIMINISH.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...HAZARDOUS SEAS WARNING UNTIL 4 AM PST
MONDAY FOR PZZ350-PZZ356-PZZ370-PZZ376.
$$
11
000
FXUS66 KPDT 230430
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
830 PM PST SUN NOV 22 2009
.UPDATE...UPPER LEVEL LOW HAS MOVED INTO WESTERN MONTANA THIS
EVENING AND ACTIVE WEATHER HAS BEEN STEADILY WINDING DOWN. RADAR
STILL SHOWS A FEW LIGHT SNOW SHOWERS IN THE EASTERN MOUNTAINS BUT
INTENSITY IS MUCH REDUCED IN THE LAST FEW HOURS. HAVE ALREADY
ALLOWED WINTER STORM WARNING FOR THE NORTHERN BLUE MOUNTAINS TO
EXPIRE ON SCHEDULE. PRESSURE GRADIENTS HAVE RELAXED CONSIDERABLY IN
THE LAST SEVERAL HOURS AND WINDS HAVE ALSO BEEN DYING DOWN. HAVE
ALLOWED WIND ADVISORY FOR THE BLUE MOUNTAIN FOOTHILLS OF OREGON TO
EXPIRE EARLIER THIS EVENING. WINDS ARE GENERALLY IN THE 10 TO 20 MPH
RANGE WITH A FEW GUSTS TO 25 OR 30 MPH. HAVE UPDATED WINDS THE REST
OF THE NIGHT TO REFLECT THE WINDS DROPPING OFF FASTER THAN FORECAST.
HAVE ALSO MADE A FEW ADJUSTMENTS TO POPS. TEMPERATURES LOOK GOOD.
UPDATE OUT SHORTLY. PERRY
&&
.PREV DISCUSSION... /ISSUED 302 PM PST SUN NOV 22 2009/
SHORT TERM...TONIGHT THROUGH TUESDAY...UPPER LEVEL LOW CENTER OVER
NORTHEAST WASHINGTON AT THIS HOUR WITH SURFACE LOW TRAILING SLIGHTLY
BEHIND ACROSS NORTH CENTRAL WASHINGTON. HAVE SEEN WIDESPREAD
ADVISORY WINDS TODAY WITH LOCALLY STRONGER GUSTS NEARING 60 MPH
NOTED JUST TODAY. OTHER STRONG WINDS HAVE BEEN REPORTED ALONG WITH
SOME DOWNED TREES AS WELL. REFER TO LOCAL STORM REPORTS FOR FURTHER
DETAILS. MANY WIND ADVISORIES AND WINTER WEATHER ADVISORIES WILL BE
ALLOWED TO EXPIRE AT 4 PM AS PLANNED WITH THE WIND ADVISORIES ALONG
THE FOOTHILLS AND THE WINTER WEATHER STATEMENTS FOR THE BLUE
MOUNTAINS LIKELY TO CONTINUE THROUGH THEIR PLANNED EXPIRATION OF 7
PM TONIGHT. SINCE THE PAIR OF LOW CIRCULATIONS HAVE PROGRESSED
SLIGHTLY FURTHER NORTH THAN EXPECTED, SNOW AMOUNTS OVER THE BLUE
MOUNTAINS HAVE BEEN ON THE LIGHT SIDE, BUT ACCUMULATION RATES HAVE
PICKED UP OVER THE LAST FEW HOURS, THUS WILL WAIT AND SEE.
WINDS AND PRECIPITATION WILL CONTINUE TO DECREASE ACROSS THE REGION
AS THE SYSTEM MOVES FURTHER EAST. EXPECT SOME LIGHT SNOW SHOWERS
WILL CONTINUE OVERNIGHT NEAR THE CASCADE CREST AND OVER THE
NORTHEASTERN MOUNTAINS BUT ACCUMULATIONS SHOULD BE FAIRLY LIGHT.
MONDAY WILL BE A RELATIVELY CALM DAY AS FLAT HIGH PRESSURE
CROSSES OVER THE REGION. THE SOUTHERN EDGE OF A COLD FRONT WILL CLIP
THE NORTHEASTERN THIRD OF THE CWA MONDAY NIGHT AND TUESDAY POSSIBLY
BRINGING ANOTHER COUPLE INCHES OF SNOW TO THE WASHINGTON CASCADE
EAST SLOPES AND NORTHEASTERN MOUNTAINS. THAT REALLY SEEMS TO BE THE
ONLY IMPACT THOUGH. IT APPEARS MOST OF THE REGION IS UNDER THE
CASCADE SHADOW INFLUENCE AND WILL REMAIN DRY. TEMPERATURES WILL
GENERALLY REMAIN ON THE COOLER SIDE AS WELL. /JBONK
LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...AN UPPER RIDGE WILL
BUILD OVER EASTERN WASHINGTON AND OREGON TUESDAY NIGHT. SUBSIDENCE
FROM THE RIDGE WILL WILL PROVIDE CLEARING SKIES AND LIGHT WINDS
WITH STRONG SURFACE INVERSIONS TUESDAY NIGHT. IN THE LOWER COLUMBIA
BASIN PATCHY FOG AND FREEZING FOG WILL FORM AT NIGHT UNDER THE
INVERSIONS AND KEEP DAYTIME TEMPERATURES WEDNESDAY BELOW NORMAL. THE
FOG WILL FORM MAINLY ALONG THE LARGE RIVERS AND STREAMS AND THEN
GRADUALLY EXPAND IN COVERAGE WEDNESDAY NIGHT AND THURSDAY. AT HIGHER
ELEVATIONS THE SURFACE INVERSIONS WILL BREAK DURING THE DAY AND
WARMER AIR ALOFT ASSOCIATED WITH THE RIDGE WILL REACH THE SURFACE TO
PRODUCE LARGE DIURNAL TEMPERATURE SPREADS. A COLD FRONT WILL MOVE
INLAND THURSDAY AFTERNOON AND BRING ANOTHER ROUND OF PRECIPITATION
TO THE FORECAST AREA THURSDAY NIGHT AND FRIDAY. MORE SYSTEMS WILL
MOVE THROUGH SATURDAY AND SUNDAY. COONFIELD
AVIATION...0Z TAFS...VFR CONDITIONS WILL PREVAIL AT ALL LOCATIONS.
STRONG SOUTHWEST TO WEST 12 TO 25 KTS WILL DIMINISH OVERNIGHT. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 32 46 37 41 / 10 10 20 10
ALW 34 47 36 42 / 10 10 20 10
PSC 29 45 35 45 / 10 10 10 10
YKM 24 42 31 49 / 10 10 20 10
HRI 28 45 32 45 / 10 10 10 10
ELN 27 40 27 40 / 10 10 30 10
RDM 20 46 25 47 / 10 10 10 10
LGD 25 40 30 42 / 20 10 20 20
GCD 21 44 25 52 / 10 10 10 10
DLS 33 45 35 49 / 20 10 40 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
MONDAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/76/76
000
FXUS65 KBOI 230347
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
847 PM MST SUN NOV 22 2009
.DISCUSSION...SNOW SHOWER ACTIVITY WAS DIMINISHING OVER THE
BOISE/WEST CENTRAL MOUNTAINS BUT FLURRIES WERE STILL OCCURRING PER
WEBCAMS. THIS TREND WILL CONTINUE WITH SCATTERED MTN SNOW SHOWERS
BECOMING ISOLATED OVERNIGHT AS THE UPPER TROUGH RESPONSIBLE FOR THE
ACTIVITY MOVES EAST. SKIES HAVE BEGUN CLEARING IN MANY AREAS OUTSIDE
OF THE BOISE/WEST CENTRAL MOUNTAINS. WINDS REMAIN GUSTY WITH SOME
GUSTS TOPPING 20 MPH BUT THOSE TOO WERE DIMINISHING. AREAS OF
CLEARING COINCIDING WITH LIGHT WINDS OVERNIGHT WILL BE LOCATIONS
PRONE TO FOG. WILL UPDATE FOR LOWER POPS AND LESS CLOUDS FOR THE
REMAINDER OF TONIGHT....OTHERWISE FORECAST IS IN GOOD SHAPE.
&&
.AVIATION...ISOLATED IFR CONDITIONS IN THE MOUNTAINS TONIGHT DUE TO
LOW CEILINGS...OTHERWISE VFR TONIGHT AND MONDAY. SURFACE WINDS
GENERALLY 10 KTS OR LESS TONIGHT WITH WINDS ALOFT MODERATE FROM THE
NORTHWEST. AS CLOUDS DECREASE TONIGHT AND WINDS BECOME
LIGHT...ESPECIALLY IN SHELTERED VALLEYS...CAN NOT RULE OUT AREAS OF
VALLEY FOG BY MONDAY MORNING. CAN EXPECT LOCAL MVFR CONDITIONS AND
ISOLATED IFR CONDITIONS IN VALLEY FOG THROUGH 17Z.
&&
.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH TUESDAY...SNOW SHOWERS IN CENTRAL IDAHO
ASSOCIATED WITH AN EXITING UPPER LEVEL TROUGH WILL ALLOW UP TO AN
ADDITIONAL 2 INCHES ACCUMULATION IN EASTERN VALLEY COUNTY AND THE
BOISE MOUNTAINS AND UP TO AN INCH OF WET SNOW GRASSY/BARE AREAS IN
THE WESTERN MAGIC VALLEY...UNTIL AROUND 6 PM. LOCALLY GUSTY WEST
WINDS TO 35 MPH LOOK TO DIMINISH TO LIGHT EARLY THIS EVENING EXCEPT
IN THE MAGIC VALLEY WHERE 15-20 MPH SUSTAINED WIND ARE EXPECTED
TONIGHT. SO PATCHY FOG IS POSSIBLE WHERE WINDS DROP OFF. QUICK
MOVING STORM WILL LEAVE COOL NW FLOW AND DRYING ACROSS THE REGION
THROUGH MONDAY NOON RESULTING TEMPERATURES 3-5F BELOW NORMAL THOUGH
HIGH ELEVATION SHELTERED AREAS /I.E. FAFI1/ COULD SEE SINGLE DIGIT
LOWS THE NEXT COUPLE NIGHTS. A SYSTEM THAT BRUSHES PRECIP NORTH OF
US IS EXPECTED TO BRING SOME CLOUDS ACROSS SE OREGON AND SW IDAHO
MONDAY AFTERNOON AND FAR NORTHERN ZONES TUESDAY AS A RIDGE/INVERSION
BUILDS NORTHWARD INTO THE AREA. COULD SEE STRATUS EARLY TUESDAY
MORNING IN THE UPPER WEISER ZONE WHERE SNOW ACCUMULATED AND INTO THE
OREGON LOWER TREASURE VALLEY WHERE DIURNAL WINDS TEND TO ACCUMULATE
SUCH LOW LEVEL MOISTURE.
LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...SHORTWAVE RIDGE WILL KEEP
INVERSION IN PLACE THROUGH THURSDAY. RESULT WILL BE ABOVE NORMAL
TEMPS IN THE MOUNTAINS WITH COLDER AIR TRAPPED IN THE VALLEYS.
MODELS HAVE HINT OF A SE WIND IN BOISE WHICH COULD BE ENOUGH TO KEEP
FOG/STRATUS OUT OF THE CITY. LOOKS LIKE A BETTER CHANCE IN LOWER
TREASURE/WEISER AND BAKER VALLEYS FOR WEDNESDAY AND THURSDAY MORNING
WITH LITTLE WIND. WHILE INVERSION REMAINS IN PLACE ON THURSDAY...
SURFACE WINDS WILL INCREASE DURING THE DAY HELPING TO SCOUR OUT THE
FOG/STRATUS IN MOST LOCATIONS. SHORTWAVE MOVES INTO THE REGION ON
FRIDAY BRINGING CHANCE OF SNOW TO THE MTNS AND RAIN TO THE VALLEYS.
CONDITIONS DRY OUT FOR SAT/SUN IN N-NW FLOW WITH NEAR NORMAL TEMPS.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...BW
AVIATION.....JA
PREV SHORT TERM...VM
PREV LONG TERM....DG/DD
000
FXUS66 KPDT 222303 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
302 PM PST SUN NOV 22 2009
UPDATED AVIATION DISCUSSION
.SHORT TERM...TONIGHT THROUGH TUESDAY...UPPER LEVEL LOW CENTER OVER
NORTHEAST WASHINGTON AT THIS HOUR WITH SURFACE LOW TRAILING SLIGHTLY
BEHIND ACROSS NORTH CENTRAL WASHINGTON. HAVE SEEN WIDESPREAD
ADVISORY WINDS TODAY WITH LOCALLY STRONGER GUSTS NEARING 60 MPH
NOTED JUST TODAY. OTHER STRONG WINDS HAVE BEEN REPORTED ALONG WITH
SOME DOWNED TREES AS WELL. REFER TO LOCAL STORM REPORTS FOR FURTHER
DETAILS. MANY WIND ADVISORIES AND WINTER WEATHER ADVISORIES WILL BE
ALLOWED TO EXPIRE AT 4 PM AS PLANNED WITH THE WIND ADVISORIES ALONG
THE FOOTHILLS AND THE WINTER WEATHER STATEMENTS FOR THE BLUE
MOUNTAINS LIKELY TO CONTINUE THROUGH THEIR PLANNED EXPIRATION OF 7
PM TONIGHT. SINCE THE PAIR OF LOW CIRCULATIONS HAVE PROGRESSED
SLIGHTLY FURTHER NORTH THAN EXPECTED, SNOW AMOUNTS OVER THE BLUE
MOUNTAINS HAVE BEEN ON THE LIGHT SIDE, BUT ACCUMULATION RATES HAVE
PICKED UP OVER THE LAST FEW HOURS, THUS WILL WAIT AND SEE.
WINDS AND PRECIPITATION WILL CONTINUE TO DECREASE ACROSS THE REGION
AS THE SYSTEM MOVES FURTHER EAST. EXPECT SOME LIGHT SNOW SHOWERS
WILL CONTINUE OVERNIGHT NEAR THE CASCADE CREST AND OVER THE
NORTHEASTERN MOUNTAINS BUT ACCUMULATIONS SHOULD BE FAIRLY LIGHT.
MONDAY WILL BE A RELATIVELY CALM DAY AS FLAT HIGH PRESSURE
CROSSES OVER THE REGION. THE SOUTHERN EDGE OF A COLD FRONT WILL CLIP
THE NORTHEASTERN THIRD OF THE CWA MONDAY NIGHT AND TUESDAY POSSIBLY
BRINGING ANOTHER COUPLE INCHES OF SNOW TO THE WASHINGTON CASCADE
EAST SLOPES AND NORTHEASTERN MOUNTAINS. THAT REALLY SEEMS TO BE THE
ONLY IMPACT THOUGH. IT APPEARS MOST OF THE REGION IS UNDER THE
CASCADE SHADOW INFLUENCE AND WILL REMAIN DRY. TEMPERATURES WILL
GENERALLY REMAIN ON THE COOLER SIDE AS WELL. /JBONK
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...AN UPPER RIDGE WILL
BUILD OVER EASTERN WASHINGTON AND OREGON TUESDAY NIGHT. SUBSIDENCE
FROM THE RIDGE WILL WILL PROVIDE CLEARING SKIES AND LIGHT WINDS
WITH STRONG SURFACE INVERSIONS TUESDAY NIGHT. IN THE LOWER COLUMBIA
BASIN PATCHY FOG AND FREEZING FOG WILL FORM AT NIGHT UNDER THE
INVERSIONS AND KEEP DAYTIME TEMPERATURES WEDNESDAY BELOW NORMAL. THE
FOG WILL FORM MAINLY ALONG THE LARGE RIVERS AND STREAMS AND THEN
GRADUALLY EXPAND IN COVERAGE WEDNESDAY NIGHT AND THURSDAY. AT HIGHER
ELEVATIONS THE SURFACE INVERSIONS WILL BREAK DURING THE DAY AND
WARMER AIR ALOFT ASSOCIATED WITH THE RIDGE WILL REACH THE SURFACE TO
PRODUCE LARGE DIURNAL TEMPERATURE SPREADS. A COLD FRONT WILL MOVE
INLAND THURSDAY AFTERNOON AND BRING ANOTHER ROUND OF PRECIPITATION
TO THE FORECAST AREA THURSDAY NIGHT AND FRIDAY. MORE SYSTEMS WILL
MOVE THROUGH SATURDAY AND SUNDAY. COONFIELD
&&
.AVIATION...0Z TAFS...VFR CONDITIONS WILL PREVAIL AT ALL LOCATIONS.
STRONG SOUTHWEST TO WEST 12 TO 25 KTS WILL DIMINISH OVERNIGHT. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 32 46 37 41 / 10 10 20 10
ALW 34 47 36 42 / 10 10 20 10
PSC 29 45 35 45 / 10 10 10 10
YKM 24 42 31 49 / 10 10 20 10
HRI 28 45 32 45 / 10 10 10 10
ELN 27 40 27 40 / 10 10 30 10
RDM 20 46 25 47 / 10 10 10 10
LGD 25 40 30 42 / 20 10 20 20
GCD 21 44 25 52 / 10 10 10 10
DLS 33 45 35 49 / 20 10 40 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ041-044.
HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR ORZ042.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ501-504.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR ORZ502.
WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ503.
WA...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ501-
502.
WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ024-028-502.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR WAZ029.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR WAZ030.
&&
THREAT INDEX
MONDAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
87/76/76
000
FXUS66 KMFR 222250
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
250 PM PST SUN NOV 22 2009
.DISCUSSION...COLD AIR ALOFT COMBINED WITH WEAKENING DYNAMICS AND
SOME UPSLOPE FLOW IS CAUSING SNOW SHOWERS OVER THE CASCADES WITH
ISOLATED RAIN SHOWERS IN THE COASTAL AREAS. UPSTREAM...A RIDGE IS
BUILDING AHEAD OF A STORM SYSTEM THAT WILL RIDE INTO THE GULF OF
ALASKA. THIS WILL REFLECT AS HIGH PRESSURE ON THE
SURFACE...INCREASING STABILITY OVER THE REGION AND ENDING ANY
SHOWERS. LIGHT WINDS...LONG NIGHTS...SURFACE HIGH PRESSURE AND
RECENT RAIN AND SNOWFALL IS A PERFECT SCENARIO FOR FOG DEVELOPING
IN THE VALLEYS IN THE WEST AND EAST SIDE. MONDAY THROUGH WEDNESDAY
WILL FEATURE FOG FORMING AFTER MIDNIGHT IN FAVORED VALLEYS. THE
FOG WILL LIFT TO LOW CLOUDS AND EVENTUALLY CLEAR AROUND NOON IN
MOST LOCATIONS. TUESDAY A WEAK COLD FRONT BRUSHES THE COASTAL
ZONES...BUT RAIN CHANCES ARE VERY LOW. CLEARING TIME WILL DICTATE
HOW WARM TEMPERATURES GET DURING THE FIRST HALF OF THE WEEK. CURRENT
FORECAST PRESENTS THE IDEA THAT WEDNESDAY WILL BE THE WARMEST DAY
AS GFS AND NAM AGREE THAT AIRMASS MAY BE 1-2 STANDARD DEVIATIONS
ABOVE AVERAGE BY THAT TIME. CLOUDS WILL BE MOSTLY OF THE MID AND
HIGH VARIETY THIS WEEK.
WEATHER FOR THANKSGIVING DAY TRAVEL IS GRADUALLY COMING INTO
FOCUS. GFS ENSEMBLE MEMBERS ALL INDICATE A SIMILAR IDEA OF AN
UPPER TROUGH AND COLD FRONT AFFECTING NORTHERN CALIFORNIA AND
OREGON BY THURSDAY AFTERNOON. SNOW LEVELS WILL INITIALLY BE
BETWEEN 5000 TO 7000 FEET BUT WILL FALL THURSDAY NIGHT AND END UP
AROUND 3500 FEET FRIDAY MORNING. THE ECMWF INDICATES MORE MOISTURE
THAN THE GFS SO WILL NEED TO MONITOR TRENDS IN THE NEAR-TERM. SISKIYOU PASS
WILL NOT LIKELY HAVE SIGNIFICANT SNOW IMPACTS WITH THIS WEATHER
SYSTEM. HOWEVER...AS COLD AIR FOLLOWS THE COLD FRONT...SOME SNOW
MAY ACCUMULATE AT PASS LEVEL LATE THURSDAY NIGHT OR EARLY FRIDAY
MORNING.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED TO CONTINUE AT ALL TAF
SITES THROUGH LATE TONIGHT WHEN FOG FORMS AT RBG AND
MFR...RESULTING IN IFR CONDITIONS THAT SHOULD LAST THROUGH MIDDAY
MONDAY. MOUNTAIN OBSCURATION WILL CONTINUE TO IMPACT MOST OF THE
HIGH TERRAIN THROUGH ABOUT 06Z WHEN DRY AIR BEGINS TO FILTER INTO
THE ELEVATED AREAS AND CLOUDS THERE DIMINISH.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...HAZARDOUS SEAS WARNING UNTIL 4 AM PST MONDAY
FOR PZZ350-PZZ356-PZZ370-PZZ376.
$$
KEENE
000
FXUS66 KPDT 222226
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
226 PM PST SUN NOV 22 2009
.SHORT TERM...TONIGHT THROUGH TUESDAY...UPPER LEVEL LOW CENTER OVER
NORTHEAST WASHINGTON AT THIS HOUR WITH SURFACE LOW TRAILING SLIGHTLY
BEHIND ACROSS NORTH CENTRAL WASHINGTON. HAVE SEEN WIDESPREAD
ADVISORY WINDS TODAY WITH LOCALLY STRONGER GUSTS NEARING 60 MPH
NOTED JUST TODAY. OTHER STRONG WINDS HAVE BEEN REPORTED ALONG WITH
SOME DOWNED TREES AS WELL. REFER TO LOCAL STORM REPORTS FOR FURTHER
DETAILS. MANY WIND ADVISORIES AND WINTER WEATHER ADVISORIES WILL BE
ALLOWED TO EXPIRE AT 4 PM AS PLANNED WITH THE WIND ADVISORIES ALONG
THE FOOTHILLS AND THE WINTER WEATHER STATEMENTS FOR THE BLUE
MOUNTAINS LIKELY TO CONTINUE THROUGH THEIR PLANNED EXPIRATION OF 7
PM TONIGHT. SINCE THE PAIR OF LOW CIRCULATIONS HAVE PROGRESSED
SLIGHTLY FURTHER NORTH THAN EXPECTED, SNOW AMOUNTS OVER THE BLUE
MOUNTAINS HAVE BEEN ON THE LIGHT SIDE, BUT ACCUMULATION RATES HAVE
PICKED UP OVER THE LAST FEW HOURS, THUS WILL WAIT AND SEE.
WINDS AND PRECIPITATION WILL CONTINUE TO DECREASE ACROSS THE REGION
AS THE SYSTEM MOVES FURTHER EAST. EXPECT SOME LIGHT SNOW SHOWERS
WILL CONTINUE OVERNIGHT NEAR THE CASCADE CREST AND OVER THE
NORTHEASTERN MOUNTAINS BUT ACCUMULATIONS SHOULD BE FAIRLY LIGHT.
MONDAY WILL BE A RELATIVELY CALM DAY AS FLAT HIGH PRESSURE
CROSSES OVER THE REGION. THE SOUTHERN EDGE OF A COLD FRONT WILL CLIP
THE NORTHEASTERN THIRD OF THE CWA MONDAY NIGHT AND TUESDAY POSSIBLY
BRINGING ANOTHER COUPLE INCHES OF SNOW TO THE WASHINGTON CASCADE
EAST SLOPES AND NORTHEASTERN MOUNTAINS. THAT REALLY SEEMS TO BE THE
ONLY IMPACT THOUGH. IT APPEARS MOST OF THE REGION IS UNDER THE
CASCADE SHADOW INFLUENCE AND WILL REMAIN DRY. TEMPERATURES WILL
GENERALLY REMAIN ON THE COOLER SIDE AS WELL. /JBONK
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...AN UPPER RIDGE WILL
BUILD OVER EASTERN WASHINGTON AND OREGON TUESDAY NIGHT. SUBSIDENCE
FROM THE RIDGE WILL WILL PROVIDE CLEARING SKIES AND LIGHT WINDS
WITH STRONG SURFACE INVERSIONS TUESDAY NIGHT. IN THE LOWER COLUMBIA
BASIN PATCHY FOG AND FREEZING FOG WILL FORM AT NIGHT UNDER THE
INVERSIONS AND KEEP DAYTIME TEMPERATURES WEDNESDAY BELOW NORMAL. THE
FOG WILL FORM MAINLY ALONG THE LARGE RIVERS AND STREAMS AND THEN
GRADUALLY EXPAND IN COVERAGE WEDNESDAY NIGHT AND THURSDAY. AT HIGHER
ELEVATIONS THE SURFACE INVERSIONS WILL BREAK DURING THE DAY AND
WARMER AIR ALOFT ASSOCIATED WITH THE RIDGE WILL REACH THE SURFACE TO
PRODUCE LARGE DIURNAL TEMPERATURE SPREADS. A COLD FRONT WILL MOVE
INLAND THURSDAY AFTERNOON AND BRING ANOTHER ROUND OF PRECIPITATION
TO THE FORECAST AREA THURSDAY NIGHT AND FRIDAY. MORE SYSTEMS WILL
MOVE THROUGH SATURDAY AND SUNDAY. COONFIELD
&&
.AVIATION...18Z TAFS...INCREASING CEILINGS AS THE COLD FRONT MOVES
THROUGH THIS MORNING. MVFR CONDITIONS AT TIMES DUE TO PASSING RAIN
AND SHOW SHOWERS. STRONG SOUTHWEST 20 TO 40 KTS WILL BE COMMON THIS
MORNING AT MOST STATIONS BUT WILL SLOWLY DIMINISH THROUGH THE DAY.
AFTER 0Z DECREASING WINDS WITH VFR CONDITIONS WILL PREVAIL AT
ALL LOCATIONS. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 32 46 37 41 / 10 10 20 10
ALW 34 47 36 42 / 10 10 20 10
PSC 29 45 35 45 / 10 10 10 10
YKM 24 42 31 49 / 10 10 20 10
HRI 28 45 32 45 / 10 10 10 10
ELN 27 40 27 40 / 10 10 30 10
RDM 20 46 25 47 / 10 10 10 10
LGD 25 40 30 42 / 20 10 20 20
GCD 21 44 25 52 / 10 10 10 10
DLS 33 45 35 49 / 20 10 40 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ041-044.
HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR ORZ042.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ501-504.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR ORZ502.
WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ503.
WA...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ501-
502.
WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ024-028-502.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR WAZ029.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR WAZ030.
&&
THREAT INDEX
MONDAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
87/76/76
000
FXUS66 KPQR 222217
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
216 PM PST SUN NOV 22 2009
.SYNOPSIS...SHOWERS CONTINUE TO SPREAD OVER THE FORECAST AREA IN COLD
UNSTABLE WESTERLY FLOW ALOFT. HIGH PRES WILL BUILD OVER WESTERN
OREGON LATER TODAY AND TONIGHT. A WARM FRONT OFF THE COAST ON MON
WILL LIFT NE TOWARDS NW OREGON AND WESTERN WA...THEN STALL ON TUE.
WED THE FRONT WILL FINALLY LIFT N INTO WA...BEFORE A COLD FRONT
PUSHES SE THROUGH THE REGION LATE THU.
&&
.SHORT TERM...SATELLITE IMAGERY SHOWS A LARGE AREA OF SHOWERS OVER
THE PACIFIC SPREADING OVER THE FORECAST AREA IN COLD UNSTABLE
WESTERLY FLOW ALOFT. DOPPLER RADAR SHOWS THE SHOWER ACTIVITY
CONTINUING...WITHOUT A LOT OF CHANGES IN INTENSITY...HOWEVER THEY ARE
BECOMING A LITTLE MORE SCATTERED. LIGHTNING DETECTION DATA HAS SHOWN
A FEW LIGHTNING STRIKES AND HAVE HAD A FEW REPORTS OF SMALL HAIL THIS
AFTERNOON. OROGRAPHICS WILL CONTINUE TO WEAKEN THIS AFTERNOON AS H8
FLOW WEAKENS...SO EXPECT SNOW ACCUMULATIONS TO DROP OFF CONSIDERABLY
AND WILL PROBABLY DROP THE WINTER STORM WARNING WITH THE AFTERNOON
PACKAGE. POST FRONTAL SHOWERS DROP OFF QUICKLY TONIGHT...LAST ON THE
N PART OF THE CASCADES.
AN AREA OF WARM AIR ADVECTION SETS UP OVER THE NW PART OF THE
FORECAST AREA MON...AND CONTINUES INTO TUE. A WEAK SHORTWAVE MOVES
ACROSS THE TOP OF THE DEVELOPING UPPER RIDGE TUE...BRINGING THE BEST
CHANCE FOR OVERRUNNING PRECIPITATION TO THE NW PART OF THE AREA ON
MON NIGHT WITH THE SHORT WAVE MOVING THROUGH THE FORECAST AREA
WEDNESDAY.
.LONG TERM...MODELS IN SOME AGREEMENT ON BRINGING A FRONTAL SYSTEM
AND ITS ASSOCIATED UPPER LEVEL TROF THROUGH THE REGION THU/THU NIGHT
FOR A RETURN TO WET WEATHER. AFTER THIS SYSTEM MOVES THROUGH...THE
WEAK HIGH PRES RIDGE REASSERTS ITSELF OVER THE FORECAST
AREA...KEEPING MOST ENERGY NORTH OF FORECAST AREA.
&&
.AVIATION...MOSTLY VFR CONDITIONS WITH PLENTY OF SHOWERS MOST VFR
THOUGH ISOLATED MVFR. SHOWERS SHOULD BEGIN TO TAPER OFF TONIGHT AS
HIGH PRESSURE BUILDS IN. PRESSURE GRADIENT STAYS STRONG ENOUGH TO
KEEP AREA MIXY TONIGHT DIMINISHING ANY CHANCES FOR FOG AND SOUTH
VALLEY MAY BE A LITTLE CLEARER BUT DRY AIR IS FILTERING INTO THE
REGION AND THIS WILL LIKELY KEEP THEM FOG FREE AS WELL. NEXT
SYSTEM BEGINS TO MOVE IN MONDAY AFTERNOON WITH RAIN STARTING AFTER
18Z ON THE COAST.
KPDX AND APPROACHES...VFR FOR THROUGH 12Z EXCEPT FOR ISOLATED MVFR
SHOWERS THEN INCREASING CHANCE FOR MVFR STRATUS MON MORNING AND THEN
THE NEXT FRONT APPROACHES AND WILL LIKELY SEE MVFR CIGS MON
AFTERNOON. WOLFE
&&
.MARINE...SOLID SMALL CRAFT WINDS WILL LET UP TONIGHT AND THEN
INCREASE AGAIN TO NEAR GALE BY TOMORROW MIDDAY WITH GUSTS NEAR 40 KT
BY TOMORROW AFTERNOON. SEAS AT 18 FT AND WILL DROP TONIGHT TO NEAR
11 FT BEFORE BUILDING TO THE MID TEENS ON MONDAY EVENING. WOLFE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...GALE WATCH MONDAY MORNING THROUGH MONDAY AFTERNOON CAPE
SHOALWATER TO CASCADE HEAD.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO
FLORENCE THROUGH MONDAY MORNING.
SMALL CRAFT ADVISORY FOR WINDS CAPE SHOALWATER TO
FLORENCE THROUGH MONDAY MORNING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS
THROUGH MON NIGHT.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS65 KBOI 222202
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
302 PM MST SUN NOV 22 2009
.SHORT TERM...TONIGHT THROUGH TUESDAY...SNOW SHOWERS IN CENTRAL
IDAHO ASSOCIATED WITH AN EXITING UPPER LEVEL TROUGH WILL ALLOW UP
TO AN ADDITIONAL 2 INCHES ACCUMULATION IN EASTERN VALLEY COUNTY AND
THE BOISE MOUNTAINS AND UP TO AN INCH OF WET SNOW GRASSY/BARE
AREAS IN THE WESTERN MAGIC VALLEY...UNTIL AROUND 6 PM. LOCALLY
GUSTY WEST WINDS TO 35 MPH LOOK TO DIMINISH TO LIGHT EARLY THIS
EVENING EXCEPT IN THE MAGIC VALLEY WHERE 15-20 MPH SUSTAINED WIND
ARE EXPECTED TONIGHT. SO PATCHY FOG IS POSSIBLE WHERE WINDS DROP
OFF. QUICK MOVING STORM WILL LEAVE COOL NW FLOW AND DRYING
ACROSS THE REGION THROUGH MONDAY NOON RESULTING TEMPERATURES 3-5F
BELOW NORMAL THOUGH HIGH ELEVATION SHELTERED AREAS /I.E. FAFI1/
COULD SEE SINGLE DIGIT LOWS THE NEXT COUPLE NIGHTS. A SYSTEM THAT
BRUSHES PRECIP NORTH OF US IS EXPECTED TO BRING SOME CLOUDS ACROSS
SE OREGON AND SW IDAHO MONDAY AFTERNOON AND FAR NORTHERN ZONES
TUESDAY AS A RIDGE/INVERSION BUILDS NORTHWARD INTO THE AREA. COULD
SEE STRATUS EARLY TUESDAY MORNING IN THE UPPER WEISER ZONE WHERE
SNOW ACCUMULATED AND INTO THE OREGON LOWER TREASURE VALLEY WHERE
DIURNAL WINDS TEND TO ACCUMULATE SUCH LOW LEVEL MOISTURE.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...SHORTWAVE RIDGE WILL KEEP
INVERSION IN PLACE THROUGH THURSDAY. RESULT WILL BE ABOVE NORMAL
TEMPS IN THE MOUNTAINS WITH COLDER AIR TRAPPED IN THE VALLEYS.
MODELS HAVE HINT OF A SE WIND IN BOISE WHICH COULD BE ENOUGH TO KEEP
FOG/STRATUS OUT OF THE CITY. LOOKS LIKE A BETTER CHANCE IN LOWER
TREASURE/WEISER AND BAKER VALLEYS FOR WEDNESDAY AND THURSDAY MORNING
WITH LITTLE WIND. WHILE INVERSION REMAINS IN PLACE ON THURSDAY...
SURFACE WINDS WILL INCREASE DURING THE DAY HELPING TO SCOUR OUT THE
FOG/STRATUS IN MOST LOCATIONS. SHORTWAVE MOVES INTO THE REGION ON
FRIDAY BRINGING CHANCE OF SNOW TO THE MTNS AND RAIN TO THE VALLEYS.
CONDITIONS DRY OUT FOR SAT/SUN IN N-NW FLOW WITH NEAR NORMAL TEMPS.
&&
.AVIATION...LOCAL IFR IN THE SW IDAHO MTNS AND MVFR IN THE WESTERN
MAGIC VALLEY THIS AFTERNOON WILL GRADUALLY IMPROVE THIS EVENING.
ISOLATED IFR IN THE MTNS OVERNIGHT DUE TO LOW CEILINGS...OTHERWISE
VFR TONIGHT AND MONDAY. SURFACE WINDS GENERALLY DECREASING TO 10 KTS
OR LESS FOR MONDAY. WINDS ALOFT DECREASE TO 20 KTS OR LESS BELOW 10K
FEET MSL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
SHORT TERM...VM
LONG TERM....DG/DD
AVIATION.....DG
000
FXUS66 KPDT 221731
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
931 AM PST SUN NOV 22 2009
.UPDATE...SOUTHWEST TO WEST WINDS ARE PICKING UP AS THE SURFACE
LOW HAS STARTED TO CROSS THE CASCADES. HAVE RECEIVED REPORTS OF
ADVISORY LEVEL GUSTS ACROSS THE FAR SOUTHERN END OF THE YAKIMA
VALLEY. HAVE ADDED A WIND ADVISORY FOR THE YAKIMA VALLEY THINKING
WINDS WILL CONTINUE DOWN-SLOPING INTO THE WESTERN VALLEY AS WELL.
WILL LET THE HIGH WIND WARNING EXPIRE AS PLANNED FOR WALLOWA
COUNTY AND THE GRANDE RONDE VALLEY AS WINDS WILL CONTINUE TO
DECREASE AND REMAIN BELOW WARNING LEVELS FOR THE REST OF THE DAY.
THE REMAINING WARNING FOR NORTH CENTRAL OREGON AND THE REMAINING
ADVISORIES APPEAR TO BE ON TRACK FOR NOW SO WILL LET THEM CONTINUE.
STILL SEEING SHOWERS CROSS THE OREGON CREST RATHER EASILY WITH
SNOW LEVEL HOVERING BETWEEN 2500 AND 3500 FEET. A QUICK INCH OF
ADDITIONAL ACCUMULATION COULD COME FROM ANY PARTICULAR SHOWER
ACROSS CENTRAL OREGON SO WILL LET THE ADVISORY CONTINUE. SEEING
MORE STRATIFORM PRECIPITATION CONTINUE ALONG THE WASHINGTON
CASCADES AND STILL THINK MOST ACCUMULATION WILL BE NEAR THE CREST
WITH THE ADVISORIES CONTINUING AS PLANNED AS WELL. MODELS
CONTINUE TO INDICATE THE BULK OF SNOWFALL ACROSS THE BLUE
MOUNTAINS WILL FALL OVER THE NEXT FEW HOURS SO WILL CONTINUE THE
WARNINGS AND ADVISORY ALTHOUGH ACCUMULATIONS THUS FAR OVER THE
NORTHERN BLUES HAVE BEEN DISAPPOINTING.
UPDATES WILL BE OUT SHORTLY. /JBONK
&&
.AVIATION...18Z TAFS...INCREASING CEILINGS AS THE COLD FRONT MOVES
THROUGH THIS MORNING. MVFR CONDITIONS AT TIMES DUE TO PASSING RAIN
AND SHOW SHOWERS. STRONG SOUTHWEST 20 TO 40 KTS WILL BE COMMON THIS
MORNING AT MOST STATIONS BUT WILL SLOWLY DIMINISH THROUGH THE DAY.
AFTER 0Z DECREASING WINDS WITH VFR CONDITIONS WILL PREVAIL AT
ALL LOCATIONS. 76
&&
.PREV DISCUSSION... /ISSUED 340 AM PST SUN NOV 22 2009/
SHORT TERM...TODAY THROUGH MONDAY...A VIGOROUS STORM SYSTEM
CONTINUES TO MOVE ONSHORE THIS MORNING. THE SURFACE LOW IS NOW OVER
SOUTHWEST WASHINGTON...FAIRLY CLOSE TO THE NAM FORECAST POSITION. A
WARM FRONT...EXTENDING FROM THE TRIPLE POINT NEAR STAMPEDE PASS
SOUTHEAST INTO EAST-CENTRAL OREGON...IS SWINGING NORTHEAST AND EAST.
EXPECT THIS FRONT TO EXIT OUR AREA IN THE NEXT COUPLE OF HOURS.
MEANWHILE THE COLD FRONT HAS STARTED TO JUMP THE CASCADE CREST AND
SHOULD BE THROUGH A GOOD PORTION OF OUR AREA BY DAYBREAK. WILL
CONTINUE ALL CURRENT WARNINGS AND ADVISORIES AS THEY ARE...BUT DID
HAVE TO ADD A SNOW ADVISORY FOR THE CENTRAL OREGON ZONE EARLIER AS
AREAS ABOVE 3500 FEET WERE GETTING A GOOD DUMP OF SNOW. SNOW IS
FALLING AT YAKIMA AND ELLENSBURG. AT THIS TIME IT LOOKS THAT THEY
WILL SEE UP TO 2 INCHES...BUT THE COLD FRONT SHOULD BE THROUGH THESE
TWO LOCATIONS BY 5 AM (POSSIBLY EARLIER). THIS WILL TURN FLOW
WESTERLY AND SIGNIFICANTLY REDUCE PRECIP AND MAY ALSO MIX OUT
TRAPPED COLD AIR AND RAISE THE SNOW LEVELS.
HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT RESULTING IN WIND
DOWN IN POST SYSTEM SHOWERS. IT WILL ALSO ALLOW FOR SOME CLEARING OF
THE SKIES FOR COOLER OVERNIGHT LOW TEMPS. A WEAK WAVE WILL RIDE OVER
THE UPPER LEVEL HIGH PRESSURE RIDGE OVER THE AREA MONDAY. THIS WAVE
MAY SPREAD SOME LIGHT SNOW OR RAIN INTO THE WASHINGTON CASCADE EAST
SLOPE AREAS. ELSEWHERE CONDITIONS WILL BE DRY. 90
LONG TERM...MONDAY NIGHT THROUGH NEXT SATURDAY...AN UPPER RIDGE
WILL BEGIN TO BUILD OVER THE PACIFIC NORTHWEST MONDAY NIGHT AND
TUESDAY. THIS WILL CAUSE MOST OF THE MOISTURE WITH ANY WEATHER
SYSTEMS TO BE PUSHED NORTHWARD NORTH OF THE UPPER JET STREAM INTO
FAR NORTHWEST WASHINGTON AND SOUTHWEST CANADA. THIS WILL SPARE THE
FORECAST AREA FROM ANY SIGNIFICANT WEATHER EVENTS THROUGH MOST OF
THE WEEK AS THE UPPER RIDGE STRENGTHENS. HOWEVER WITH THE UPPER
RIDGE DEVELOPING AND THE PRESENCE OF THE RECENT PRECIPITATION PATCHY
VALLEY FOG AND FREEZING FOG WILL DEVELOP OVER THE LOWER COLUMBIA
BASIN AND ADJACENT VALLEYS. IT WILL FORM MAINLY ALONG THE LARGE
RIVERS AND STREAMS AT FIRST AND THEN GRADUALLY EXPAND IN COVERAGE BY
WEDNESDAY AND WILL PERSIST THROUGH THURSDAY. AND PRECIPITATION WILL
BE MAINLY LIGHT RAIN AND SNOW SHOWERS OVER THE MOUNTAINS. A COLD
FRONT WITH A WEATHER SYSTEM WILL APPROACH THE CWA LATE THURSDAY INTO
FRIDAY BRINGING THE NEXT BETTER CHANCE OF PRECIPITATION TO THE
FORECAST AREA BY FRIDAY INTO SATURDAY. TEMPERATURES WILL BE NEAR TO
ABOVE NORMAL IN HIGHER TERRAIN AND NEAR TO BELOW NORMAL IN THE LOWER
TERRAIN THAT IS CAUGHT UNDER TEMPERATURE INVERSIONS AND/OR WITH
FOG/LOW CLOUDS. 88
AVIATION...12Z TAFS...LIFR TO IFR CONDITIONS WILL PREVAIL AT KRDM
AND KYKM AT TIMES DUE TO SNOW OR A MIX OF RAIN AND SNOW WITH LOW
CEILINGS. A COLD FRONT WILL PASS THESE AREAS ALLOWING PRECIPITATION
TO DECREASE WITH INCREASING CEILINGS...WHICH WILL ALLOW MVFR TO VFR
CONDITIONS TO RETURN FOR MOST OF THE TIME WITH OCCASIONAL PERIODS
OF IFR DUE TO PASSING RAIN AND SHOW SHOWERS. ELSEWHERE MAINLY VFR
CONDITIONS WILL PREVAIL BUT THERE WILL BE PERIODS OF IFR TO MVFR DUE
TO RAIN OR SNOW SHOWERS WITH LOWERED CEILINGS THIS MORNING...WITH
IMPROVING CONDITIONS THIS AFTERNOON. STRONG SOUTH TO EAST WINDS OF
AT LEAST 25 TO 40 KTS WILL BE COMMON EARLY THIS MORNING AT MOST
STATIONS BUT WILL SLOWLY DIMINISH THROUGH THE DAY INTO TONIGHT AND
TURN TO THE SOUTHWEST TO WEST. TONIGHT DECREASING WINDS WITH VFR
CONDITIONS WILL PREVAIL AT ALL LOCATIONS. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 47 32 46 37 / 70 10 10 10
ALW 48 34 47 36 / 80 10 10 20
PSC 53 29 45 35 / 60 10 10 20
YKM 48 23 42 31 / 40 10 10 20
HRI 52 28 45 32 / 60 10 10 10
ELN 44 27 40 27 / 60 10 20 30
RDM 45 20 46 25 / 50 10 10 10
LGD 42 25 40 30 / 80 20 10 10
GCD 42 21 44 25 / 60 10 10 10
DLS 49 33 45 35 / 40 20 10 40
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ041-044.
HIGH WIND WARNING UNTIL 10 AM PST THIS MORNING FOR ORZ049-050.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR ORZ502.
HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR ORZ042.
WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR ORZ043.
WIND ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR ORZ043.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ501-504.
WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ503.
WA...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ501-
502.
WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ024-028-502.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR WAZ030.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR WAZ027-029.
&&
THREAT INDEX
TODAY : RED
MONDAY : GREEN
TUESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
87/76
000
FXUS66 KMFR 221709
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
909 AM PST SUN NOV 22 2009
.DISCUSSION...DISCUSSION...FIRST LOOK AT VISIBLE IMAGERY SUGGESTS PARTLY CLOUDY
SKIES ACROSS THE REGION...WITH THE MOST SUN AT THE COAST AND THE
MOST CLOUDS ALONG THE CASCADES AND EAST SIDE. MORNING MFR SOUNDING
SHOWS FAIRLY STABLE CONDITIONS BUT COLD AIR CUMULUS OFFSHORE
SUGGESTS INSTABILITY WILL INCREASE DURING THE LATE MORNING AND
AFTERNOON...FUELING SOME ISOLATED SHOWERS OVER THE HIGHER TERRAIN.
BY TONIGHT...STABILITY WILL INCREASE ACROSS THE REGION AND SKIES
WILL CLEAR SOME...HELPING TO GENERATE FOG IN MANY VALLEYS. THIS
PATTERN WILL CONTINUE THROUGH WEDNESDAY WITH LATE NIGHT AND
MORNING FOG IN THE LOW ELEVATIONS TRANSITIONING TO PARTLY SUNNY
SKIES DURING THE AFTERNOON. CLIMATOLOGY SUGGESTS THAT LOCATIONS
LIKE ROSEBURG AND MEDFORD WILL LIKELY HAVE LOW CLOUDS THROUGH
ABOUT NOON ON MONDAY THROUGH WEDNESDAY.
LOOKING TOWARD THE BUSY THANKSGIVING TRAVEL PERIOD...ECMWF AND GFS
ARE IN BETTER SYNC THAN PREVIOUS DAYS WITH A SOLUTION THAT
INVOLVES A TROUGH REACHING THE OREGON COASTAL WATERS THURSDAY.
PRECIPITATION AMOUNTS LOOK TO BE LIGHT TO MODERATE FOR THIS TIME
OF YEAR. INITIAL LOOK AT SNOW LEVELS SUGGEST THEY WILL BE ABOVE
SISKIYOU PASS LEVEL...ABOUT 5000 FEET. PRECIPITATION TAPERS OFF
DURING THE DAY ON FRIDAY.
&&
.AVIATION...FLYING WEATHER WILL FEATURE MOUNTAIN OBSCURATION TODAY
OVER THE HIGHER TERRAIN WITH MOSTLY VFR CEILINGS AT LOWER
ELEVATIONS. TONIGHT...LOW CLOUDS AND FOG WILL FORM IN THE VALLEYS
AFFECTING RBG AND MFR AFTER 10Z...WITH IFR CONDITIONS LASTING
THROUGH LATE MONDAY MORNING. KEENE
&&
.PREV DISCUSSION... /ISSUED 311 AM PST SUN NOV 22 2009/
DISCUSSION...THE STRONG COLD FRONT IS TRAVERSING OUR REGION AS
INDICATED BY THE 00Z GFS. IT IS ABOUT TO REACH THE CASCADES AND
SHOULD MOVE EAST OF LAKE AND MODOC COUNTIES BY AROUND 10 AM.
PRECIPITATION IS LIGHT TO MODERATE WITH SNOW LEVELS AT 3500 TO
4000 FEET. THERE WERE FEW ADJUSTMENTS TO MAKE TO THE FIRST 24
HOURS OF THE FORECAST. THE WIND AND WINTER WEATHER HEADLINE
PRODUCTS ARE EXPECTED TO REMAIN APPROPRIATE THROUGH THEIR
CURRENTLY SCHEDULED EXPIRATIONS...4 AND 7 AM RESPECTIVELY FOR THE
COASTAL AND SHASTA VALLEY WINDS AND 7 AM FOR THE CASCADE AND EAST
SIDE WINTER WEATHER ADVISORY.
SHOWERS WILL BE NUMEROUS BEHIND THE FRONT THEN GRADUALLY TAPER OFF
FROM LATE MORNING INTO THIS EVENING...WITH EVENING CLEARING
LEADING TO A MUCH COLDER NIGHT AND AREAS OF FREEZING FOG.
THE MAIN UPPER LEVEL FEATURE MONDAY THROUGH WEDNESDAY WILL BE A
HIGH PRESSURE RIDGE CENTERED OFFSHORE FROM CENTRAL AND SOUTHERN
CALIFORNIA. A COUPLE OF WEAK TROUGHS WILL RIDE OVER THE TOP OF THE
RIDGE INTO WASHINGTON AND NORTHERN OREGON. THUS...IT WILL BE DRY
ASIDE FROM A SLIGHT CHANCE OF COASTAL SHOWERS NORTH OF CAPE
BLANCO. THE PROXIMITY OF THE TROUGHS WILL ALLOW PERIODS OF SCATTERED
TO BROKEN HIGH CLOUDS. LATE NIGHT AND MORNING FOG WILL BE
PREVALENT IN WEST SIDE VALLEYS.
POPS HAVE BEEN LOWERED FOR WEDNESDAY NIGHT AND ALSO FOR
THANKSGIVING DAY...ESPECIALLY IN AREAS EAST OF THE CASCADES WITH
THE ECMWF AND GFS COMING INTO CLOSER AGREEMENT ON A SLOWER SOLUTION
WITH THE NEXT COLD FRONT. SNOW LEVELS DO NOT LOOK TO BE ESPECIALLY
LOW WITH THE FRONT...AROUND 5000 TO 5500 FEET WHICH IS HIGHER THAN
NORMAL. GIVEN THAT THE MODELS HAVE JUST NOW COME INTO BETTER
AGREEMENT...I WILL KEEP THURSDAY EVENING INTO FRIDAY MORNING POPS IN
THE CHANCE CATEGORY.
BEYOND FRIDAY...THE ECMWF IS STRONGER THAN THE GFS WITH A RIDGE
BUILDING OVER THE OFFSHORE WATERS. THUS...THE ECMWF SOLUTION FOR
FRIDAY NIGHT THROUGH THE WEEKEND WOULD BE COLDER BUT DRIER. I WILL
CONTINUE WITH A COMPROMISE BETWEEN THE TWO MODELS FOR THE LATTER
PART OF THE FORECAST PERIOD. ANY LIGHT SHOWERS DEPICTED BY THE
GFS WOULD BE MAINLY FROM THE CASCADES WESTWARD.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH SURF ADVISORY UNTIL 3 PM PST THIS AFTERNOON FOR ORZ021-
ORZ022.
CA...NONE.
PACIFIC COASTAL WATERS...HAZARDOUS SEAS WARNING UNTIL 4 AM PST MONDAY
FOR PZZ350-PZZ356-PZZ370-PZZ376.
$$
000
FXUS65 KBOI 221700
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1000 AM MST SUN NOV 22 2009
.DISCUSSION...WEBCAMS SHOW MANY SNOW COVERED ROADS AS LOW AS 3100
FT MSL IN SE OREGON AND SW IDAHO. RADAR AND SATELLITE IMAGERY AND
SURFACE OBS INDICATE THE COLD FRONT ACROSS CENTRAL OREGON. SNOW
SHOWERS HAVE DECERASED IN COVERAGE IN HARNEY COUNTY WHERE THE
SN/BLSN ADVISORY HAS BEEN DISCONTINUED. A BAND OF HEAVIER SNOW
SHOWERS IS MOVING THROUGH BOISE AND MCCALL. A SPOTTER IN PINE
REPORTED 4 INCHES AS OF 959 AM. GUSTY SE WINDS TO 30 MPH SHIFTING
TO SW/NW BEHIND FRONT STILL ON TRACK. NO OTHER CHANGES THIS
MORNING.
&&
.AVIATION...WIDESPREAD IFR IN SNOW OVER SW IDAHO MTNS THIS MORNING
BECOMING SCATTERED IN COVERAGE THIS AFTERNOON. VFR/MVFR IN LOWER
VALLEYS WITH RAIN/SNOW MIX ENDING FROM WEST TO EAST. IN SE OREGON
WIDELY SCATTERED SNOW SHOWERS AND ACCOMPANYING IFR CONDITIONS INTO
EARLY AFTERNOON. STRONG WINDS SURFACE AND ALOFT TODAY DECREASING
TONIGHT. GUSTS TO 35 KTS AT THE SURFACE WITH WEST WINDS OVER 50 KTS
ALOFT.
&&
.PREV DISCUSSION...
SHORT TERM...VIGOROUS STORM SYSTEM CURRENTLY PUSHING INTO THE
FORECAST AREA WITH SNOW AND WIND. SYSTEM IS FAST MOVING EMBEDDED
WITHIN 120-140 KNOT JETSTREAM CORE...THUS MAIN IMPACTS NOT EXPECTED
TO LAST MORE THAN A FEW HOURS OVER ANY ONE AREA TODAY. HAVE ADDED
HARNEY AND MALHEUR COUNTIES IN OREGON TO THE WINTER WEATHER
ADVISORIES WITH LIGHT TO MODERATE SNOW AND INCREASING WINDS.
SYNOPTICALLY...A WARM FRONT IS MOVING THROUGH SOUTHEAST OREGON WITH
A COLD FRONT ALIGNED NORTH SOUTH JUST EAST OF THE CASCADES. SYSTEM
EXPECTED TO OCCLUDE LATER THIS AFTERNOON OVER OUR AREA AND WEAKEN.
NEVERTHELESS...SEVERAL INCHES OF NEW SNOW CAN BE EXPECTED IN THE
NORTHERN MOUNTAINS WITH 1 TO 3 INCHES IN VALLEYS SOUTH TO THE SNAKE
RIVER. LESS SNOW IS FORECAST SOUTHWARD TOWARD THE NEVADA STATE LINE.
DUE TO THE QUICK MOVEMENT TO THE SYSTEM...HEAVY PRECIP IS NOT
EXPECTED TO LAST FOR A LONG TIME BUT INCREASING WINDS WITH BLOWING
SNOW WILL BE JUST AS IMPORTANT AN IMPACT AS THE ACTUAL SNOW FALL.
TREASURE AND MAGIC VALLEYS A LITTLE MORE TRICKY WITH SOUNDING
PROFILES INDICATING LIGHT SNOW EARLY THIS MORNING FOLLOWED BY A
MIXTURE...THEN TO ALL RAIN BY THIS AFTERNOON AS WINDS TURN WESTERLY
BEHIND FRONT...ALTHOUGH NOT EXPECTING SIGNIFICANT SNOW
ACCUMULATIONS. LINGERING SNOW SHOWERS TO REMAIN TONIGHT IN THE UPPER
TROF AXIS WITH DRIER CONDITIONS ANTICIPATED FOR MONDAY AS YET
ANOTHER RIDGE BUILDS OVER THE AREA.
LONG TERM..MONDAY NIGHT THROUGH SUNDAY...DRY CONDITIONS MONDAY
THROUGH THURSDAY AS AN UPPER LEVEL RIDGE AMPLIFIES OVER NRN
CALIFORNIA/NEVADA. THUS...STRENGTH OF SURFACE INVERSION CONTINUES TO
BE THE MAIN FORECAST CHALLENGE. MODEL SOUNDINGS INDICATE SOME MIXING
TUESDAY AFTERNOON...NOT UNTIL WEDNESDAY DOES INVERSION LOOK TO REACH
ITS FULL POTENTIAL. EXPECT BELOW NORMAL VALLEY TEMPERATURES /ABOVE
NORMAL TEMPS IN MTN VALLEYS/ AND FOG ON WEDNESDAY...AND POSSIBLY
EVEN THURSDAY. MODELS IN BETTER AGREEMENT WITH AN UPPER LEVEL TROUGH
PROGGED TO MOVE INTO THE FORECAST AREA EARLY FRIDAY. EXPECT CHANCES
FOR VALLEY RAIN/SNOW AND MOUNTAIN SNOW ON FRIDAY...THEN DRIER ON
SATURDAY AND SUNDAY AS SYSTEM QUICKLY EXITS THE FORECAST AREA.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...WINTER WEATHER ADVISORY UNTIL 2 PM MST THIS AFTERNOON FOR IDZ011-
IDZ013-IDZ033.
OR...WINTER WEATHER ADVISORY UNTIL 11 AM MST /10 AM PST/ THIS MORNING
FOR ORZ063.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ062.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...VM
AVIATION.....DG
PREV SHORT TERM...GS
PREV LONG TERM....MT/JT
000
FXUS66 KPQR 221639
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
839 AM PST SUN NOV 22 2009
.SYNOPSIS...A STRONG SURFACE LOW OVER WESTERN WASHINGTON THIS MORNING
WILL CONTINUE TO MOVE EAST TODAY AND WEAKEN. HIGH PRES WILL BUILD IN
OVER WESTERN OREGON LATER TODAY AND TONIGHT. A WARM FRONT OFF THE
COAST ON MON WILL LIFT NE TOWARDS NW OREGON AND WESTERN WA....THEN
STALL ON TUE. WED THE FRONT WILL FINALLY LIFT N INTO WA...BEFORE A
COLD FRONT PUSHES SE THROUGH THE REGION THU.
&&
.SHORT TERM...SATELLITE IMAGERY SHOWS THE LOW PRESSURE SYSTEM THAT
CAME ONSHORE OVERNIGHT NEAR WILLAPA BAY IS NOW IN WESTERN WASHINGTON
NEAR 48N 123W. THE ASSOCIATED OCCLUDED FRONT ARCS JUST EAST OF THE
OREGON CASCADES. WINDS OVER THE FORECAST AREA ARE BELOW WARNING
CRITERIA...HOWEVER THERE ARE STILL STRONG WESTERLY WINDS ON THE
BACKSIDE OF THE FRONT WITH WINDS STILL GUSTING IN THE 40S ALONG THE
COAST.
DOPPLER RADAR SHOWING GOOD SHOWER ACTIVITY OVER THE FORECAST AREA
THIS MORNING. CASCADES HAVE ALREADY RECEIVED 8 TO 12 INCHES OF NEW
SNOW OVERNIGHT. STRONG OROGRAPHIC WESTERLY FLOW WILL KEEP SHOWERS
GOING THIS MORNING...AND WILL KEEP THE WINTER STORM WARNING GOING
TODAY. OROGRAPHICS WEAKEN THIS AFTERNOON AS H8 FLOW WEAKENS...SO WE
SHOULD SEE SNOW ACCUMULATIONS DROP OFF CONSIDERABLY THIS AFTERNOON.
POST FRONTAL SHOWERS DROP OFF QUICKLY TONIGHT...LAST ON THE N PART OF
THE CASCADES. AN AREA OF WARM AIR ADVECTION SETS UP OVER THE NW PART
OF THE FORECAST AREA MON...AND CONTINUES INTO TUE. A WEAK SHORTWAVE
MOVES ACROSS THE TOP OF THE DEVELOPING UPPER RIDGE TUE...BRINGING THE
BEST CHANCE FOR OVERRUNNING PRECIPITATION TO THE NW PART OF THE AREA
ON TUE.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...WEAK HIGH PRES
RIDGE OVER THE FORECAST AREA CONTINUES TO PUSH ENERGY NORTH OF
FORECAST AREA MID WEEK. IT MANAGES TO DELAY THE ARRIVAL OF A SECOND
SYSTEM THROUGH THUR. MODEL SOLUTIONS DIVERGE TOWARD THE END OF THE
WEEK AND HAVE LITTLE CONFIDENCE IN THEM. AT THIS TIME WILL GO WITH
CLIMATOLOGY UNTIL THERE IS SOME CONSISTENCY BETWEEN THE MODELS..
&&
.AVIATION...STRONG FRONT NOW PUSHING INTO EASTERN OREGON...WITH
MOSTLY VFR CONDITIONS. PLENTY OF SHOWERS TO PUSH INLAND THIS
MORNING...WITH OCCASIONAL MVFR. GUSTY SOUTHWEST WINDS WILL EASE
GRADUALLY BETWEEN NOW AND 18Z.
KPDX AND APPROACHES...VFR TODAY...BUT EXPECT OCCASIONAL MVFR CIGS
DOWN TO 2000 FT WITH SHOWERS...ESPECIALLY THIS MORNING. GUSTY SOUTH
TO SOUTHWEST WINDS WILL CONTINUE UNTIL 17Z...THEN GRADUALLY EASE.
WOLFE
&&
.MARINE...WORST IS OVER...BUT STILL A LOT OF GRADIENT ON BACK SIDE
OF THE LOW. WINDS STILL HITTING 40 KT...WILL MAINTAIN SOLID GALES
THROUGH EARLY AFTERNOON. SEAS TOPPING AROUND 22 TO 24 FT THIS
AM...BUT WILL EASE TO THE MID TO LOWER TEENS BY TONIGHT. NEXT SYSTEM
WILL MOVE ACROSS THE COASTAL WATERS ON MON...WITH NEAR GALE FORCE
WINDS. DIFFERENCE IS THAT THE PARENT LOW WILL PASS MUCH FURTHER TO
THE N OF THE AREA. WOLFE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...GALE WARNING FOR THE COASTAL WATERS FROM CAPE SHOALWATER TO
FLORENCE UNTIL NOON TODAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS
THROUGH SUN NIGHT.
WINTERSTORM WARNING FOR THE S WA AND N AND CENTRAL OREGON
CASCADES TODAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KPDT 221141
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
340 AM PST SUN NOV 22 2009
UPDATED AVIATION DISCUSSION
.SHORT TERM...TODAY THROUGH MONDAY...A VIGOROUS STORM SYSTEM
CONTINUES TO MOVE ONSHORE THIS MORNING. THE SURFACE LOW IS NOW OVER
SOUTHWEST WASHINGTON...FAIRLY CLOSE TO THE NAM FORECAST POSITION. A
WARM FRONT...EXTENDING FROM THE TRIPLE POINT NEAR STAMPEDE PASS
SOUTHEAST INTO EAST-CENTRAL OREGON...IS SWINGING NORTHEAST AND EAST.
EXPECT THIS FRONT TO EXIT OUR AREA IN THE NEXT COUPLE OF HOURS.
MEANWHILE THE COLD FRONT HAS STARTED TO JUMP THE CASCADE CREST AND
SHOULD BE THROUGH A GOOD PORTION OF OUR AREA BY DAYBREAK. WILL
CONTINUE ALL CURRENT WARNINGS AND ADVISORIES AS THEY ARE...BUT DID
HAVE TO ADD A SNOW ADVISORY FOR THE CENTRAL OREGON ZONE EARLIER AS
AREAS ABOVE 3500 FEET WERE GETTING A GOOD DUMP OF SNOW. SNOW IS
FALLING AT YAKIMA AND ELLENSBURG. AT THIS TIME IT LOOKS THAT THEY
WILL SEE UP TO 2 INCHES...BUT THE COLD FRONT SHOULD BE THROUGH THESE
TWO LOCATIONS BY 5 AM (POSSIBLY EARLIER). THIS WILL TURN FLOW
WESTERLY AND SIGNIFICANTLY REDUCE PRECIP AND MAY ALSO MIX OUT
TRAPPED COLD AIR AND RAISE THE SNOW LEVELS.
HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT RESULTING IN WIND
DOWN IN POST SYSTEM SHOWERS. IT WILL ALSO ALLOW FOR SOME CLEARING OF
THE SKIES FOR COOLER OVERNIGHT LOW TEMPS. A WEAK WAVE WILL RIDE OVER
THE UPPER LEVEL HIGH PRESSURE RIDGE OVER THE AREA MONDAY. THIS WAVE
MAY SPREAD SOME LIGHT SNOW OR RAIN INTO THE WASHINGTON CASCADE EAST
SLOPE AREAS. ELSEWHERE CONDITIONS WILL BE DRY. 90
.LONG TERM...MONDAY NIGHT THROUGH NEXT SATURDAY...AN UPPER RIDGE
WILL BEGIN TO BUILD OVER THE PACIFIC NORTHWEST MONDAY NIGHT AND
TUESDAY. THIS WILL CAUSE MOST OF THE MOISTURE WITH ANY WEATHER
SYSTEMS TO BE PUSHED NORTHWARD NORTH OF THE UPPER JET STREAM INTO
FAR NORTHWEST WASHINGTON AND SOUTHWEST CANADA. THIS WILL SPARE THE
FORECAST AREA FROM ANY SIGNIFICANT WEATHER EVENTS THROUGH MOST OF
THE WEEK AS THE UPPER RIDGE STRENGTHENS. HOWEVER WITH THE UPPER
RIDGE DEVELOPING AND THE PRESENCE OF THE RECENT PRECIPITATION PATCHY
VALLEY FOG AND FREEZING FOG WILL DEVELOP OVER THE LOWER COLUMBIA
BASIN AND ADJACENT VALLEYS. IT WILL FORM MAINLY ALONG THE LARGE
RIVERS AND STREAMS AT FIRST AND THEN GRADUALLY EXPAND IN COVERAGE BY
WEDNESDAY AND WILL PERSIST THROUGH THURSDAY. AND PRECIPITATION WILL
BE MAINLY LIGHT RAIN AND SNOW SHOWERS OVER THE MOUNTAINS. A COLD
FRONT WITH A WEATHER SYSTEM WILL APPROACH THE CWA LATE THURSDAY INTO
FRIDAY BRINGING THE NEXT BETTER CHANCE OF PRECIPITATION TO THE
FORECAST AREA BY FRIDAY INTO SATURDAY. TEMPERATURES WILL BE NEAR TO
ABOVE NORMAL IN HIGHER TERRAIN AND NEAR TO BELOW NORMAL IN THE LOWER
TERRAIN THAT IS CAUGHT UNDER TEMPERATURE INVERSIONS AND/OR WITH
FOG/LOW CLOUDS. 88
&&
.AVIATION...12Z TAFS...LIFR TO IFR CONDITIONS WILL PREVAIL AT KRDM
AND KYKM AT TIMES DUE TO SNOW OR A MIX OF RAIN AND SNOW WITH LOW
CEILINGS. A COLD FRONT WILL PASS THESE AREAS ALLOWING PRECIPITATION
TO DECREASE WITH INCREASING CEILINGS...WHICH WILL ALLOW MVFR TO VFR
CONDITIONS TO RETURN FOR MOST OF THE TIME WITH OCCASIONAL PERIODS
OF IFR DUE TO PASSING RAIN AND SHOW SHOWERS. ELSEWHERE MAINLY VFR
CONDITIONS WILL PREVAIL BUT THERE WILL BE PERIODS OF IFR TO MVFR DUE
TO RAIN OR SNOW SHOWERS WITH LOWERED CEILINGS THIS MORNING...WITH
IMPROVING CONDITIONS THIS AFTERNOON. STRONG SOUTH TO EAST WINDS OF
AT LEAST 25 TO 40 KTS WILL BE COMMON EARLY THIS MORNING AT MOST
STATIONS BUT WILL SLOWLY DIMINISH THROUGH THE DAY INTO TONIGHT AND
TURN TO THE SOUTHWEST TO WEST. TONIGHT DECREASING WINDS WITH VFR
CONDITIONS WILL PREVAIL AT ALL LOCATIONS. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 47 32 46 37 / 70 10 10 10
ALW 48 34 47 36 / 80 10 10 20
PSC 53 29 45 35 / 60 10 10 20
YKM 48 23 42 31 / 40 10 10 20
HRI 52 28 45 32 / 60 10 10 10
ELN 44 27 40 27 / 70 10 20 30
RDM 45 20 46 25 / 50 10 10 10
LGD 42 25 40 30 / 80 20 10 10
GCD 42 21 44 25 / 60 10 10 10
DLS 49 33 45 35 / 40 20 10 40
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 10 AM PST THIS MORNING FOR ORZ049-050.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR ORZ502.
HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR ORZ042.
WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR ORZ043.
WIND ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR ORZ043.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ501-504.
WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ503.
WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ041-044.
WA...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR
WAZ501-502.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR WAZ030.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR WAZ029.
WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ024-028.
&&
THREAT INDEX
TODAY : RED
MONDAY : GREEN
TUESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
90/88/88
000
FXUS66 KMFR 221111
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
311 AM PST SUN NOV 22 2009
.DISCUSSION...THE STRONG COLD FRONT IS TRAVERSING OUR REGION AS
INDICATED BY THE 00Z GFS. IT IS ABOUT TO REACH THE CASCADES AND
SHOULD MOVE EAST OF LAKE AND MODOC COUNTIES BY AROUND 10 AM.
PRECIPITATION IS LIGHT TO MODERATE WITH SNOW LEVELS AT 3500 TO
4000 FEET. THERE WERE FEW ADJUSTMENTS TO MAKE TO THE FIRST 24
HOURS OF THE FORECAST. THE WIND AND WINTER WEATHER HEADLINE
PRODUCTS ARE EXPECTED TO REMAIN APPROPRIATE THROUGH THEIR
CURRENTLY SCHEDULED EXPIRATIONS...4 AND 7 AM RESPECTIVELY FOR THE
COASTAL AND SHASTA VALLEY WINDS AND 7 AM FOR THE CASCADE AND EAST
SIDE WINTER WEATHER ADVISORY.
SHOWERS WILL BE NUMEROUS BEHIND THE FRONT THEN GRADUALLY TAPER OFF
FROM LATE MORNING INTO THIS EVENING...WITH EVENING CLEARING
LEADING TO A MUCH COLDER NIGHT AND AREAS OF FREEZING FOG.
THE MAIN UPPER LEVEL FEATURE MONDAY THROUGH WEDNESDAY WILL BE A
HIGH PRESSURE RIDGE CENTERED OFFSHORE FROM CENTRAL AND SOUTHERN
CALIFORNIA. A COUPLE OF WEAK TROUGHS WILL RIDE OVER THE TOP OF THE
RIDGE INTO WASHINGTON AND NORTHERN OREGON. THUS...IT WILL BE DRY
ASIDE FROM A SLIGHT CHANCE OF COASTAL SHOWERS NORTH OF CAPE
BLANCO. THE PROXIMITY OF THE TROUGHS WILL ALLOW PERIODS OF SCATTERED
TO BROKEN HIGH CLOUDS. LATE NIGHT AND MORNING FOG WILL BE
PREVALENT IN WEST SIDE VALLEYS.
POPS HAVE BEEN LOWERED FOR WEDNESDAY NIGHT AND ALSO FOR
THANKSGIVING DAY...ESPECIALLY IN AREAS EAST OF THE CASCADES WITH
THE ECMWF AND GFS COMING INTO CLOSER AGREEMENT ON A SLOWER SOLUTION
WITH THE NEXT COLD FRONT. SNOW LEVELS DO NOT LOOK TO BE ESPECIALLY
LOW WITH THE FRONT...AROUND 5000 TO 5500 FEET WHICH IS HIGHER THAN
NORMAL. GIVEN THAT THE MODELS HAVE JUST NOW COME INTO BETTER
AGREEMENT...I WILL KEEP THURSDAY EVENING INTO FRIDAY MORNING POPS IN
THE CHANCE CATEGORY.
BEYOND FRIDAY...THE ECMWF IS STRONGER THAN THE GFS WITH A RIDGE
BUILDING OVER THE OFFSHORE WATERS. THUS...THE ECMWF SOLUTION FOR
FRIDAY NIGHT THROUGH THE WEEKEND WOULD BE COLDER BUT DRIER. I WILL
CONTINUE WITH A COMPROMISE BETWEEN THE TWO MODELS FOR THE LATTER
PART OF THE FORECAST PERIOD. ANY LIGHT SHOWERS DEPICTED BY THE
GFS WOULD BE MAINLY FROM THE CASCADES WESTWARD.
&&
.AVIATION...A STRONG COLD FRONT JUST WEST OF THE CASCADES WILL
CONTINUE TO MOVE EAST AND EXIT OUR REGION AROUND 10 AM THIS MORNING.
THE FRONT HAS LIGHT TO MODERATE PRECIPITATION WITH MOUNTAIN
OBSCURATIONS...STRONG SOUTHERLY WINDS AND AREAS OF MVFR CEILINGS.
POST-FRONTAL SHOWERS WILL GRADUALLY DECREASE THIS AFTERNOON INTO
THIS EVENING WITH VFR BECOMING THE PREVAILING CONDITION. VALLEY FOG
WILL DEVELOP LATE TONIGHT INTO MONDAY MORNING WEST OF THE CASCADES WITH
AREAS OF IFR CONDITIONS.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 7 AM PST THIS MORNING FOR ORZ027-
ORZ028-ORZ029-ORZ030.
WIND ADVISORY UNTIL 7 AM PST THIS MORNING FOR ORZ031.
HIGH WIND WARNING UNTIL 4 AM PST EARLY THIS MORNING FOR ORZ021-
ORZ022.
CA...WIND ADVISORY UNTIL 4 AM PST EARLY THIS MORNING FOR CAZ081.
PACIFIC COASTAL WATERS...STORM WARNING UNTIL 4 AM PST EARLY THIS
MORNING FOR PZZ350-PZZ370.
HAZARDOUS SEAS WARNING UNTIL 4 AM PST MONDAY FOR PZZ350-PZZ356-
PZZ370-PZZ376.
GALE WARNING UNTIL 4 AM PST EARLY THIS MORNING FOR PZZ356-PZZ376.
$$
DW
000
FXUS66 KPDT 221059
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
259 AM PST SUN NOV 22 2009
.SHORT TERM...TODAY THROUGH MONDAY...A VIGOROUS STORM SYSTEM
CONTINUES TO MOVE ONSHORE THIS MORNING. THE SURFACE LOW IS NOW OVER
SOUTHWEST WASHINGTON...FAIRLY CLOSE TO THE NAM FORECAST POSITION. A
WARM FRONT...EXTENDING FROM THE TRIPLE POINT NEAR STAMPEDE PASS
SOUTHEAST INTO EAST-CENTRAL OREGON...IS SWINGING NORTHEAST AND EAST.
EXPECT THIS FRONT TO EXIT OUR AREA IN THE NEXT COUPLE OF HOURS.
MEANWHILE THE COLD FRONT HAS STARTED TO JUMP THE CASCADE CREST AND
SHOULD BE THROUGH A GOOD PORTION OF OUR AREA BY DAYBREAK. WILL
CONTINUE ALL CURRENT WARNINGS AND ADVISORIES AS THEY ARE...BUT DID
HAVE TO ADD A SNOW ADVISORY FOR THE CENTRAL OREGON ZONE EARLIER AS
AREAS ABOVE 3500 FEET WERE GETTING A GOOD DUMP OF SNOW. SNOW IS
FALLING AT YAKIMA AND ELLENSBURG. AT THIS TIME IT LOOKS THAT THEY
WILL SEE UP TO 2 INCHES...BUT THE COLD FRONT SHOULD BE THROUGH THESE
TWO LOCATIONS BY 5 AM (POSSIBLY EARLIER). THIS WILL TURN FLOW
WESTERLY AND SIGNIFICANTLY REDUCE PRECIP AND MAY ALSO MIX OUT
TRAPPED COLD AIR AND RAISE THE SNOW LEVELS.
HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT RESULTING IN WIND
DOWN IN POST SYSTEM SHOWERS. IT WILL ALSO ALLOW FOR SOME CLEARING OF
THE SKIES FOR COOLER OVERNIGHT LOW TEMPS. A WEAK WAVE WILL RIDE OVER
THE UPPER LEVEL HIGH PRESSURE RIDGE OVER THE AREA MONDAY. THIS WAVE
MAY SPREAD SOME LIGHT SNOW OR RAIN INTO THE WASHINGTON CASCADE EAST
SLOPE AREAS. ELSEWHERE CONDITIONS WILL BE DRY. 90
.LONG TERM...MONDAY NIGHT THROUGH NEXT SATURDAY...AN UPPER RIDGE
WILL BEGIN TO BUILD OVER THE PACIFIC NORTHWEST MONDAY NIGHT AND
TUESDAY. THIS WILL CAUSE MOST OF THE MOISTURE WITH ANY WEATHER
SYSTEMS TO BE PUSHED NORTHWARD NORTH OF THE UPPER JET STREAM INTO
FAR NORTHWEST WASHINGTON AND SOUTHWEST CANADA. THIS WILL SPARE THE
FORECAST AREA FROM ANY SIGNIFICANT WEATHER EVENTS THROUGH MOST OF
THE WEEK AS THE UPPER RIDGE STRENGTHENS. HOWEVER WITH THE UPPER
RIDGE DEVELOPING AND THE PRESENCE OF THE RECENT PRECIPITATION PATCHY
VALLEY FOG AND FREEZING FOG WILL DEVELOP OVER THE LOWER COLUMBIA
BASIN AND ADJACENT VALLEYS. IT WILL FORM MAINLY ALONG THE LARGE
RIVERS AND STREAMS AT FIRST AND THEN GRADUALLY EXPAND IN COVERAGE BY
WEDNESDAY AND WILL PERSIST THROUGH THURSDAY. AND PRECIPITATION WILL
BE MAINLY LIGHT RAIN AND SNOW SHOWERS OVER THE MOUNTAINS. A COLD
FRONT WITH A WEATHER SYSTEM WILL APPROACH THE CWA LATE THURSDAY INTO
FRIDAY BRINGING THE NEXT BETTER CHANCE OF PRECIPITATION TO THE
FORECAST AREA BY FRIDAY INTO SATURDAY. TEMPERATURES WILL BE NEAR TO
ABOVE NORMAL IN HIGHER TERRAIN AND NEAR TO BELOW NORMAL IN THE LOWER
TERRAIN THAT IS CAUGHT UNDER TEMPERATURE INVERSIONS AND/OR WITH
FOG/LOW CLOUDS. 88
&&
.AVIATION...PREVIOUS DISCUSSION...06Z TAFS...A PACIFIC WEATHER
SYSTEM WILL MOVE THROUGH THE AREA BRINGING RAIN AND SNOW LATER
TONIGHT AND TOMORROW MORNING BEFORE TAPERING OFF IN THE AFTERNOON.
VFR CONDITIONS WITH BROKEN MID AND HIGH CLOUDS ARE EXPECTED THROUGH
22/09Z THEN AS THE RAIN AND SNOW MOVES IN...MVFR CEILINGS ARE
EXPECTED TO DEVELOP IN AND NEAR THE CASCADES AND IN THE EASTERN
MOUNTAINS AFFECTING KDLS...KRDM AND KYKM AT TIMES THROUGH 22/20Z.
MVFR VISIBILITIES ARE POSSIBLE NEAR THE HEAVIER SNOW SHOWERS AT KYKM
AND KRDM. KPSC...KPDT AND KALW WILL GENERALLY STAY AT LOW VFR
CEILINGS THOUGH STRONGER SHOWERS COULD HAVE BRIEF PERIODS OF MVFR
CEILINGS. CONDITIONS WILL IMPROVE TO VFR LEVELS AT ALL TAF LOCATIONS
AFTER 22/20Z. WINDS AT KDLS...KRDM...KYKM AND KPSC WILL INCREASE
LATER TONIGHT TO 10 TO 20 KTS WITH GUSTS TO 30 KTS AT ALL TAF
LOCATIONS THROUGH 23/00Z THEN DECREASE TO BELOW 15 KTS AFTER THAT.
KPDT AND KALW WILL SEE 10 TO 20 KTS WITH GUSTS TO 30 KTS THROUGH
22/12Z...INCREASE TO 15 TO 25 KTS WITH GUSTS TO 40 KTS THROUGH
23/02Z THE DECREASE BACK TO 10 TO 20 KTS WITH GUSTS TO 25 KTS AFTER
THAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 47 32 46 37 / 70 10 10 10
ALW 48 34 47 36 / 80 10 10 20
PSC 53 29 45 35 / 60 10 10 20
YKM 48 23 42 31 / 40 10 10 20
HRI 52 28 45 32 / 60 10 10 10
ELN 44 27 40 27 / 70 10 20 30
RDM 45 20 46 25 / 50 10 10 10
LGD 42 25 40 30 / 80 20 10 10
GCD 42 21 44 25 / 60 10 10 10
DLS 49 33 45 35 / 40 20 10 40
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 10 AM PST THIS MORNING FOR ORZ049-050.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR ORZ502.
HIGH WIND WARNING UNTIL 4 PM PST THIS AFTERNOON FOR ORZ042.
WINTER WEATHER ADVISORY UNTIL NOON PST TODAY FOR ORZ043.
WIND ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR ORZ043.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ501-504.
WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING FOR ORZ503.
WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ORZ041-044.
WA...WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ501-
502.
WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING FOR WAZ030.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR WAZ029.
WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR WAZ024-028.
&&
THREAT INDEX
TODAY : RED
MONDAY : GREEN
TUESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
90/88/88
000
FXUS65 KBOI 221039
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
340 AM MST SUN NOV 22 2009
.SHORT TERM...VIGOROUS STORM SYSTEM CURRENTLY PUSHING INTO THE
FORECAST AREA WITH SNOW AND WIND. SYSTEM IS FAST MOVING EMBEDDED
WITHIN 120-140 KNOT JETSTREAM CORE...THUS MAIN IMPACTS NOT EXPECTED
TO LAST MORE THAN A FEW HOURS OVER ANY ONE AREA TODAY. HAVE ADDED
HARNEY AND MALHEUR COUNTIES IN OREGON TO THE WINTER WEATHER
ADVISORIES WITH LIGHT TO MODERATE SNOW AND INCREASING WINDS.
SYNOPTICALLY...A WARM FRONT IS MOVING THROUGH SOUTHEAST OREGON WITH
A COLD FRONT ALIGNED NORTH SOUTH JUST EAST OF THE CASCADES. SYSTEM
EXPECTED TO OCCLUDE LATER THIS AFTERNOON OVER OUR AREA AND WEAKEN.
NEVERTHELESS...SEVERAL INCHES OF NEW SNOW CAN BE EXPECTED IN THE
NORTHERN MOUNTAINS WITH 1 TO 3 INCHES IN VALLEYS SOUTH TO THE SNAKE
RIVER. LESS SNOW IS FORECAST SOUTHWARD TOWARD THE NEVADA STATE LINE.
DUE TO THE QUICK MOVEMENT TO THE SYSTEM...HEAVY PRECIP IS NOT
EXPECTED TO LAST FOR A LONG TIME BUT INCREASING WINDS WITH BLOWING
SNOW WILL BE JUST AS IMPORTANT AN IMPACT AS THE ACTUAL SNOW FALL.
TREASURE AND MAGIC VALLEYS A LITTLE MORE TRICKY WITH SOUNDING
PROFILES INDICATING LIGHT SNOW EARLY THIS MORNING FOLLOWED BY A
MIXTURE...THEN TO ALL RAIN BY THIS AFTERNOON AS WINDS TURN WESTERLY
BEHIND FRONT...ALTHOUGH NOT EXPECTING SIGNIFICANT SNOW
ACCUMULATIONS. LINGERING SNOW SHOWERS TO REMAIN TONIGHT IN THE UPPER
TROF AXIS WITH DRIER CONDITIONS ANTICIPATED FOR MONDAY AS YET
ANOTHER RIDGE BUILDS OVER THE AREA.
.LONG TERM..MONDAY NIGHT THROUGH SUNDAY...DRY CONDITIONS MONDAY
THROUGH THURSDAY AS AN UPPER LEVEL RIDGE AMPLIFIES OVER NRN
CALIFORNIA/NEVADA. THUS...STRENGTH OF SURFACE INVERSION CONTINUES TO
BE THE MAIN FORECAST CHALLENGE. MODEL SOUNDINGS INDICATE SOME MIXING
TUESDAY AFTERNOON...NOT UNTIL WEDNESDAY DOES INVERSION LOOK TO REACH
ITS FULL POTENTIAL. EXPECT BELOW NORMAL VALLEY TEMPERATURES /ABOVE
NORMAL TEMPS IN MTN VALLEYS/ AND FOG ON WEDNESDAY...AND POSSIBLY
EVEN THURSDAY. MODELS IN BETTER AGREEMENT WITH AN UPPER LEVEL TROUGH
PROGGED TO MOVE INTO THE FORECAST AREA EARLY FRIDAY. EXPECT CHANCES
FOR VALLEY RAIN/SNOW AND MOUNTAIN SNOW ON FRIDAY...THEN DRIER ON
SATURDAY AND SUNDAY AS SYSTEM QUICKLY EXITS THE FORECAST AREA.
&&
.AVIATION...WIDESPREAD IFR CONDITIONS IN SNOW /ALL AREAS/ THROUGH
20Z. AFTER 20Z...SHOWERS WILL SLOWLY TAPER OFF ACROSS SE OREGON BUT
PERSIST ACROSS SW ID. STILL EXPECTING SEVERAL HOURS OF IFR
CONDITIONS AT KBOI LATE SUNDAY MORNING...GENERALLY 14Z-19Z. MODERATE
SE SURFACE WINDS WITH LOCALIZED GUSTS TO 35 KTS...WILL BECOME
MODERATE WESTERLY THIS AFTERNOON. STRONG /40-50 KTS/ WESTERLY WINDS
ALOFT.
OUTLOOK...DEVELOPMENT OF INVERSION NEXT WEEK WILL BRING CHANCE OF
IFR CONDITIONS IN FOG/STRATUS TO TREASURE/BAKER/WEISER VALLEYS ON
WEDNESDAY.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...WINTER WEATHER ADVISORY FROM 4 AM TO 2 PM MST SUNDAY FOR IDZ033.
WINTER WEATHER ADVISORY FROM 4 AM TO 2 PM MST SUNDAY FOR IDZ011-
IDZ013.
OR...WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM PST SUNDAY FOR
ORZ061-ORZ62-ORZ63.
&&
$$
WEATHER.GOV/BOISE
SHORT TERM...GS
LONG TERM....MT/JT
AVIATION.....MT
000
FXUS66 KPQR 221030
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
230 AM PST SUN NOV 22 2009
.SYNOPSIS...A STRONG SURFACE LOW OVER SW WA THIS MORNING WILL
CONTINUE TO MOVE E TODAY AND WEAKEN. HIGH PRES WILL BUILD IN OVER
WESTERN OREGON LATER TODAY AND TONIGHT. A WARM FRONT OFF THE COAST
ON MON WILL LIFT NE TOWARDS NW OREGON AND WESTERN WA....THEN STALL
ON TUE. WED THE FRONT WILL FINALLY LIFT N INTO WA...BEFORE A COLD
FRONT PUSHES SE THROUGH THE REGION THU.
&&
.SHORT TERM...SURFACE LOW PASSED JUST N OF BUOY 46089 A FEW HOURS
AGO...APPARENTLY MOVING ENE HEADED TOWARDS ROUGHLY WILLAPA BAY. COLD
FRONT HAS PUSHED E INTO THE CENTRAL OREGON COAST WITH PEAK GUSTS
AROUND 80 MPH. BUOYS INDICATE AN IMPRESSIVE WIND FIELD IN THE POST
FRONTAL WESTERLY FLOW...WITH STORM FORCE GUSTS CONTINUING THROUGH
09Z AT 46089 AND 46050. BASED ON E WINDS ALONG THE N OREGON
COAST...FRONT APPEARS TO BE OCCLUDED N OF KTMK...SO ANY HIGH WINDS N
OF THERE WILL NEED TO COME OUT OF THE SW BEHIND THE FRONT. STRONG
PRESSURE RISES BEHIND THE COLD FRONT HAVE MAINTAINED HIGH WINDS FOR
A COUPLE HOURS BEHIND THE FRONT. WITH THE STRONG PRESSURE RISES
BEHIND THE FRONT...WILL LIKELY NEED TO HANG ONTO THE INLAND WIND
ADVISORY EARLY THIS MORNING. ELSEWHERE EXPECT BE ABLE TO DROP THE
HIGH WIND WARNINGS WITH THE NEXT FORECAST PACKAGE.
SNOW INTENSITY PICKED UP IN THE CASCADES AFTER ROUGHLY 10 PM AS
HEAVIER BANDS OF PRECIPITATION LIFTED UP. SATELLITE AND RADAR
SUGGEST AT LEAST ONE MORE BAND OF ENHANCED PRECIPITATION YET EARLY
THIS MORNING...BEFORE THE STRONG OROGRAPHIC WESTERLY FLOW KICKS IN
BEHIND THE FRONT. OROGRAPHICS WEAKEN IN THE AFTERNOON AS H8 FLOW
WEAKENS...SO WE SHOULD SEE SNOW ACCUMULATIONS DROP OFF CONSIDERABLY
IN THE AFTERNOON.
POST FRONTAL SHOWERS DROP OFF QUICKLY TONIGHT...LAST ON THE N PART
OF THE CASCADES. AN AREA OF WARM AIR ADVECTION SETS UP OVER THE NW
PART OF THE FORECAST AREA MON...AND CONTINUES INTO TUE. A WEAK
SHORTWAVE MOVES ACROSS THE TOP OF THE DEVELOPING UPPER RIDGE
TUE...BRINGING THE BEST CHANCE FOR OVERRUNNING PRECIPITATION TO THE
NW PART OF THE AREA ON TUE.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
WEAK HIGH PRES RIDGE OVER THE FORECAST AREA CONTINUES TO PUSH ENERGY
NORTH OF FORECAST AREA MID WEEK. IT MANAGES TO DELAY THE ARRIVAL OF
A SECOND SYSTEM THROUGH THUR. MODEL SOLUTIONS DIVERGE TOWARD THE END
OF THE WEEK AND HAVE LITTLE CONFIDENCE IN THEM. AT THIS TIME WILL GO
WITH CLIMATOLOGY UNTIL THERE IS SOME CONSISTENCY BETWEEN THE MODELS..
&&
.AVIATION...STRONG FRONT NOW PUSHING ACROSS THE REGION...WITH MOSTLY
VFR CONDITIONS. PLENTY OF SHOWERS TO PUSH INLAND THIS MORNING...WITH
OCCASIONAL MVFR. MAIN STORY IS THE GUSTY SOUTH TO SOUTHWEST WINDS
OVER REGION. WINDS WILL EASE GRADUALLY BETWEEN 14Z AND 18Z.
KPDX AND APPROACHES...VFR TODAY...BUT EXPECT OCCASIONAL MVFR CIGS
DOWN TO 2000 FT WITH SHOWERS...ESPECIALLY AFTER 14Z. GUSTY SOUTH TO
SOUTHWEST WINDS WILL CONTINUE UNTIL 17Z...THEN GRADUALLY EASE.
&&
.MARINE...WORST IS OVER...BUT STILL A LOT OF GRADIENT ON BACK SIDE
OF THE LOW. WITH WINDS STILL HITTING 45 TO 50 KT...WILL MAINTAIN
STORM WARNING UNTIL 7 AM. THEN SOLID GALES AFTERWARDS. SEAS TOPPING
AROUND 22 TO 24 FT THIS AM...BUT LIKE THE WIND THESE TOO SHALL EASE
TODAY. NEXT SYSTEM WILL MOVE ACROSS THE COASTAL WATERS ON MON...WITH
NEAR GALE FORCE WIND. DIFFERENCE IS THAT THE PARENT LOW WILL PASS
MUCH FURTHER TO THE N OF THE AREA. &&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...STORM WARNING FOR THE COASTAL WATERS FROM CAPE SHOALWATER TO
FLORENCE UNTIL 7 AM THIS MORNING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS
THROUGH SUN NIGHT.
WINTER STORM WARNING FOR THE S WA AND N AND CENTRAL OREGON
CASCADES TODAY.
WIND ADVISORY FOR THE WILLAMETTE VALLEY...THE LOWER
COLUMBIA...AND THE I-5 CORRIDOR FOR THIS EVENING THROUGH
7 AM.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KPDT 220600 AAA
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
1000 PM PST SAT NOV 21 2009
UPDATED AVIATION DISCUSSION.
.UPDATE...A DEVELOPING FRONT IS APPROACHING THE PACIFIC NORTHWEST
COAST AND WILL COME ASHORE BEFORE MIDNIGHT. RADAR ON THE WEST SIDE
OF THE CASCADES IS SHOWING SUBSTANTIAL RETURNS AND LIGHT RAIN HAS
BEEN FALLING IN PORTLAND AND SEATTLE FOR A COUPLE OF HOURS. STAMPEDE
PASS IS REPORTING MODERATE SNOW AT THIS TIME BUT AM NOT SEEING SNOW
ON ANY OF THE WEB CAMS IN THE CASCADE PASSES. EXPECT THAT
PRECIPITATION WILL BEGIN IN THE NEXT HOUR OR TWO NEAR THE CASCADE
CREST AND WORK ITS WAY ACROSS THE AREA OVERNIGHT. WINDS HAVE BEEN
LIGHT BUT RADAR VELOCITY RETURNS ARE INCREASING ON BOTH LOCAL AND
PORTLAND AND SEATTLE RADARS SHOWING THAT STRONGER WINDS WILL BE
PRESENT ALOFT BEFORE LONG. WIND PROFILER DATA SHOWS AN INCREASING
TREND AS WELL. WATER VAPOR LOOP SHOWS AN AREA OF DARKENING BEHIND
THE FRONT THAT IS INCREASING IN SIZE AND STRENGTH AS THE FRONT
DEVELOPS. ALTHOUGH WINDS WILL TAKE A FEW HOURS TO TAKE OFF...WILL
LEAVE WIND GRIDS AS IS THOUGH STRONG WINDS MAY BE SPOTTY IN COVERAGE
AT FIRST. LATEST OBSERVATIONS ARE STARTING TO SHOW SOME 15 TO 25 MPH
WINDS SO WIND FORECAST...ADVISORIES AND WARNINGS LOOK GOOD.
TEMPERATURES ARE IN MANY CASES NOT TOO FAR FROM FORECAST OVERNIGHT
LOW TEMPERATURES WHICH IS A BIT CONCERNING BUT AS SOUTH WINDS
INCREASE...TEMPERATURES SHOULD INCREASE SO WILL LEAVE FORECAST AS
IS. OVERALL...FORECAST IS IN GOOD SHAPE. NO UPDATE PLANNED. PERRY
&&
.AVIATION...06Z TAFS...A PACIFIC WEATHER SYSTEM WILL MOVE THROUGH
THE AREA BRINGING RAIN AND SNOW LATER TONIGHT AND TOMORROW MORNING
BEFORE TAPERING OFF IN THE AFTERNOON. VFR CONDITIONS WITH BROKEN MID
AND HIGH CLOUDS ARE EXPECTED THROUGH 22/09Z THEN AS THE RAIN AND
SNOW MOVES IN...MVFR CEILINGS ARE EXPECTED TO DEVELOP IN AND NEAR
THE CASCADES AND IN THE EASTERN MOUNTAINS AFFECTING KDLS...KRDM AND
KYKM AT TIMES THROUGH 22/20Z. MVFR VISIBILITIES ARE POSSIBLE NEAR
THE HEAVIER SNOW SHOWERS AT KYKM AND KRDM. KPSC...KPDT AND KALW WILL
GENERALLY STAY AT LOW VFR CEILINGS THOUGH STRONGER SHOWERS COULD
HAVE BRIEF PERIODS OF MVFR CEILINGS. CONDITIONS WILL IMPROVE TO VFR
LEVELS AT ALL TAF LOCATIONS AFTER 22/20Z. WINDS AT
KDLS...KRDM...KYKM AND KPSC WILL INCREASE LATER TONIGHT TO 10 TO 20
KTS WITH GUSTS TO 30 KTS AT ALL TAF LOCATIONS THROUGH 23/00Z THEN
DECREASE TO BELOW 15 KTS AFTER THAT. KPDT AND KALW WILL SEE 10 TO 20
KTS WITH GUSTS TO 30 KTS THROUGH 22/12Z...INCREASE TO 15 TO 25 KTS
WITH GUSTS TO 40 KTS THROUGH 23/02Z THE DECREASE BACK TO 10 TO 20
KTS WITH GUSTS TO 25 KTS AFTER THAT. PERRY
&&
.PREV DISCUSSION... /ISSUED 332 PM PST SAT NOV 21 2009/
SHORT TERM...TONIGHT THROUGH MONDAY...THOUGHTS HAVE CHANGED LITTLE
FROM THE PREVIOUS OVERNIGHT SHIFT. MODELS REMAINED VERY CONSISTENT
WITH THE PROGRESSION OF THE SYSTEM ACROSS THE AREA. WITH A COUPLE OF
PRONOUNCED ISSUES DEALT WITH TODAY.
FIRST, DECIDED TO FOLLOW THE SURFACE LOW AS SHOWN BY THE NAM WITH
THE 18Z GFS NOW LENDING THE CLOSEST SUPPORT OF RECENT RUNS. THIS
GIVES A VERY TIGHT PRESSURE GRADIENT ACROSS MOST OF THE AREA AS THE
SURFACE LOW TRACKS ACROSS THE WASHINGTON CASCADES AND THE LOWER
COLUMBIA BASIN BEFORE LIFTING NORTHEAST LATER TOMORROW. THESE
GRADIENTS, COMBINED WITH A VERY STABLE LOWER LEVEL AIR MASS, WILL
GIVE A PROLONGED PERIOD OF STRONG WINDS ALOFT DOWN TOWARD THE
SURFACE. WILL ISSUE NUMEROUS WIND ADVISORIES AND HIGH WIND WARNINGS
AS A RESULT.
THE SECOND ISSUE DEALS WITH SNOWFALL. SNOW LEVEL WILL BE SOMEWHAT
VARIABLE WITH A BRIEF PERIOD OF WARM AIR ADVECTION AS WARM DIFFLUENT
AIR CROSSES THE CASCADES TONIGHT. THE WASHINGTON CASCADES WILL SEE
SIGNIFICANT ACCUMULATIONS MAINLY TONIGHT WITH THE MAJOR PASSES
IMPACTED. DO THINK MAINLY WESTERN AREAS WILL BEAR THE BRUNT AFTER
THE COLD FRONT PASSES LATER TONIGHT AND SUNDAY. THE BLUE MOUNTAINS
WILL START SEEING ACCUMULATIONS LATER TONIGHT AT THE HIGHER
ELEVATIONS AND PASSES BUT SNOW LEVELS WILL DROP AND ACCUMULATION
RATES WILL INCREASE MAINLY TOMORROW AFTER THE COLD FRONT PASSES AND
A NORTHWESTERLY FLOW DEVELOPS. BOTH AREAS WILL SEE SIGNIFICANT
BLOWING SNOW BUT DONT HAVE THE CONFIDENCE TO GO WITH A BLIZZARD
WARNING, BUT IT BEARS WATCHING HOWEVER.
OTHER MOUNTAIN AREAS WILL SEE SNOW AND MAYBE SOME BLOWING AS WELL,
BUT SHOULD STAY BELOW ADVISORY AMOUNTS. PRECIPITATION SHOULD BEGIN
TAPERING OFF ACROSS THE WEST BY TOMORROW AFTERNOON AND GRADUALLY
TAPER OFF ACROSS THE EAST TOMORROW EVENING. /JBONK
LONG TERM...MONDAY NIGHT THROUGH SATURDAY...A WEAK SYSTEM WILL
BREAK UP MONDAY NIGHT IT RIDES OVER A BUILDING UPPER LEVEL RIDGE.
THE BUILDING RIDGE WILL MOVE SLOWLY EAST OVER THE PACIFIC NORTHWEST
TUESDAY. THE DEPARTING SYSTEM WILL COMBINE WILL UPSLOPE FLOW IN THE
MOUNTAINS TO KEEP A SLIGHT CHANCE OF SHOWERS IN NORTHEAST OREGON
TUESDAY. ALSO...SLOPOVER PRECIPITATION MAY OCCUR NEAR THE CASCADES.
SUBSIDENCE ASSOCIATED WITH THE RIDGE WILL PROVIDE LIGHT WINDS AND
CLEARING SKIES WITH THE STRONG SURFACE INVERSIONS TUESDAY NIGHT. IN
THE LOWER COLUMBIA BASIN PATCHY FOG AND FREEZING FOG WILL FORM AT
NIGHT UNDER THE INVERSIONS AND KEEP DAYTIME TEMPERATURES WEDNESDAY
BELOW NORMAL. AT HIGHER ELEVATIONS THE SURFACE INVERSIONS WILL BREAK
DURING THE DAY AND WARMER AIR ALOFT ASSOCIATED WITH THE RIDGE WILL
REACH THE SURFACE TO PRODUCE LARGE DIURNAL TEMPERATURE SPREADS.
WEDNESDAY NIGHT THROUGH FRIDAY THERE ARE DRAMATIC DIFFERENCES
BETWEEN THE GFS AND ECMWF MODELS EVEN THOUGH BOTH HAVE SOUTHWEST
FLOW AT 500 MB. THE 0Z ECMWF HAS A MORE PROGRESSIVE PATTERN WITH A
FRONT AT AN ANGLE TO THE 500 MB FLOW THAT WILL MOVE INTO EASTERN
WASHINGTON AND OREGON AND FORM A DEFORMATION ZONE OVER THE BLUE
MOUNTAINS THAT DROPS HALF AN INCH OF RAIN THURSDAY. THE 12Z GFS HAS
THE FRONT PARALLEL TO THE 500 MB FLOW SO IT REMAINS OFFSHORE UNTIL
FRIDAY. THE GFS ENSEMBLE RUNS SHOW 500 MB FLOW RUNNING TO BOTH
EXTREMES WITH NO CLUSTERING. DECIDED TO MAKE LITTLE CHANGE TO
EXISTING FORECAST WITH A CHANCE OF POPS MOST PLACES AND LIKELY POPS
OVER THE MOUNTAINS. THINK ECMWF IS OVERBLOWN WITH AMOUNT OF
PRECIPITATION UNLESS THE DEFORMATION BAND DOES SET UP...BUT DID
TREND TOWARD IT BY KEEPING AT LEAST A CHANCE OF POPS ACROSS THE
AREA. WHEN THE 12Z RUN OF THE ECMWF ARRIVED IT WAS SLOWER WITH NO
DEFORMATION BAND...BUT IT STILL SUPPORTED THE FASTER ARRIVAL OF THE
FRONT DURING THE DAY THURSDAY. BOTH MODELS HAD PRECIPITATION FRIDAY
WITH THE GFS PUSHING THE FRONT THROUGH AND THE ECMWF MOVING THE
UPPER LEVEL TROUGH THROUGH. WITH LOW CONFIDENCE DUE TO MODEL
DIFFERENCES KEPT A LOW CHANCE POPS ACROSS THE AREA SATURDAY.
COONFIELD
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 41 47 31 43 / 80 70 10 10
ALW 39 48 32 43 / 90 80 10 10
PSC 37 51 30 44 / 90 50 10 10
YKM 32 45 29 44 / 90 40 10 10
HRI 38 49 29 45 / 80 50 10 10
ELN 34 39 26 39 / 90 70 10 20
RDM 35 45 24 47 / 80 40 10 10
LGD 36 42 23 40 / 80 80 20 10
GCD 34 41 21 44 / 70 60 10 10
DLS 37 49 32 47 / 80 40 20 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 10 AM PST SUNDAY FOR ORZ049-050.
WINTER STORM WARNING UNTIL 7 PM PST SUNDAY FOR ORZ502.
HIGH WIND WARNING FROM 1 AM TO 4 PM PST SUNDAY FOR ORZ042.
WIND ADVISORY UNTIL 1 PM PST SUNDAY FOR ORZ043.
WIND ADVISORY UNTIL 7 PM PST SUNDAY FOR ORZ501-504.
WINTER WEATHER ADVISORY UNTIL 7 PM PST SUNDAY FOR ORZ503.
WIND ADVISORY FROM 4 AM TO 4 PM PST SUNDAY FOR ORZ041-044.
WA...WINTER WEATHER ADVISORY UNTIL 4 PM PST SUNDAY FOR WAZ501-502.
WINTER STORM WARNING UNTIL 7 PM PST SUNDAY FOR WAZ030.
WIND ADVISORY UNTIL 7 PM PST SUNDAY FOR WAZ029.
WIND ADVISORY FROM 4 AM TO 4 PM PST SUNDAY FOR WAZ024-028.
&&
THREAT INDEX
SUNDAY : RED
MONDAY : GREEN
TUESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/76/83
000
FXUS66 KMFR 220548
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
902 PM PST SAT NOV 21 2009
.DISCUSSION...TIGHT...RAPIDLY DEVELOPING DEEP SURFACE LOW MOVING
QUICKLY TOWARD THE NORTHERN OREGON COAST. NAM POSITION SLIGHTLY
TOO FAR NORTH AND EAST. EXPECT THE TRACK TO BE SOUTH OF NAM
FORECAST POSITION. CURRENT FORECASTS TAKE THIS INTO ACCOUNT AND
LOOK GOOD. STORM FORCE WINDS ALREADY IN THE OUTER WATERS NORTH
OF THE CAPE AND WINDS SHOULD COME UP RAPIDLY IN THE NEXT 3 HOURS
ALONG THE COAST. PROGS SHOW THE WEATHER SETTLING DOWN SUNDAY AND
MONDAY...THEN HIGH PRESSURE DOMINATING UNTIL THE END OF NEXT WEEK.
NO UPDATES NEEDED THIS EVENING.
&&
.AVIATION...CURRENT VFR CEILINGS WILL BE SHORT-LIVED AS THE
OFFSHORE FRONT DROPS CEILING TO MVFR IN LOW CLOUDS AND SHOWERS IN
THE NEXT FEW HOURS. COASTAL TERMINALS WILL LIKELY BE IMPACTED BY
LOW LEVEL WIND SHEAR WITH GUSTY WINDS TO 35KT BUT EVEN STRONGER
50-60KT WINDS JUST ABOVE THE SURFACE. STRONG WINDS WILL ALSO
IMPACT THE CASCADES AND THE EAST SIDE LATE TONIGHT AND SUNDAY
MORNING. MOUNTAINS AND EAST SIDE WILL HAVE SNOW LATE TONIGHT AND
SUNDAY MORNING...REDUCING VISIBILITIES. MOUNTAIN OBSCURATION WILL
BE WIDESPREAD BY TONIGHT THROUGH SUNDAY AS DEEP MOISTURE PUSHES
INTO THE REGION.
&&
.PREV DISCUSSION... /ISSUED 301 PM PST SAT NOV 21 2009/
DISCUSSION...QUICK-MOVING DEVELOPING FRONTAL SYSTEM WILL IMPACT
THE CWA TONIGHT THROUGH SUNDAY MORNING. THE MAIN IMPACTS WILL BE
STRONG WINDS AND SOME SNOW OVER THE CASCADES AND THE EAST SIDE.
THE FAST MOVEMENT OF THIS SYSTEM...ALONG WITH MORE WESTERLY
WINDS...WILL FAVOR THE CASCADES RECEIVING MORE SNOWFALL AND THE
MOUNT SHASTA AREA RECEIVING LESS THAN THE PREVIOUS STORM. MODELS
HAVE SETTLED ON A 990MB LOW CENTERED WEST OF THE WA/OR BORDER LATE
TONIGHT. THE STRONGEST WINDS WILL IMPACT COASTAL WATERS AND
COASTAL ZONES TONIGHT...WITH WINDS AFFECTING THE CASCADES THROUGH
THE EAST SIDE LATE TONIGHT THROUGH SUNDAY MORNING. VERY STRONG H8
FLOW OF 50KT IS NOTED OVER NORTHWESTERN PORTION OF THE CWA LATE
TONIGHT...BUT STABILITY SHOULD KEEP MOST OF THIS AREA FROM GETTING
ADVISORY LEVEL WINDS. THIS SITUATION MAY NEED TO BE LOOKED AT
DURING THE LATE AFTERNOON. SIGNIFICANT SNOW WILL FALL DURING A
SHORT PERIOD BETWEEN TONIGHT AND TOMORROW MORNING. A FOOT IS
POSSIBLE IN THE HIGHER TERRAIN OF THE CASCADES WITH SEVERAL INCHES
EXPECTED EAST OF THE CASCADES IN KLAMATH COUNTY. ON SUNDAY IN THE
POSTFRONTAL ENVIRONMENT EXPECT SNOW SHOWERS ABOVE 3500 FEET AND
RAIN SHOWERS IN THE LOWER ELEVATIONS. RIDGING WILL BUILD OVER THE
REGION SUNDAY NIGHT...ESSENTIALLY ENDING THE PRECIPITATION OVER
THE CWA.
MODELS HAVE BEEN VERY PERSISTENT WITH UPPER RIDGING FROM MONDAY
THROUGH WEDNESDAY OVER NORTHERN CA AND SOUTHWESTERN OR...WITH THE
RESULTANT WEATHER IMPACTS BEING MORNING FOG MONDAY THROUGH
WEDNESDAY IN THE FAVORED LOW ELEVATION AREAS LIKE THE ROGUE AND
ILLINOIS VALLEYS...AND THE UMPQUA BASIN. A WEAK WARM FRONT BRUSHES
THE COAST ON WEDNESDAY BUT WILL NOT LIKELY RESULT IN ANY
SIGNIFICANT PRECIPITATION. GFS AND ECMWF BOTH PUT AN END TO THE
DRY WEATHER ON THANKSGIVING DAY BUT THEIR SOLUTIONS ARE STILL
FAIRLY DIFFERENT. THERE ARE STILL UNKNOWNS REGARDING THE FORECAST
FOR THURSDAY...BUT AT THIS POINT IT SEEMS REASONABLE TO EXPECT
LIGHT SNOW IN THE MOUNTAINS AND LIGHT RAIN IN THE VALLEYS ON LATE
THURSDAY. IT STILL SEEMS THERE WILL NOT BE A LARGE STORM FOR
THANKSGIVING DAY TRAVELERS IN THE REGION.
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 7 AM PST SUNDAY FOR ORZ027-ORZ028-
ORZ029-ORZ030.
WIND ADVISORY UNTIL 7 AM PST SUNDAY FOR ORZ031.
HIGH WIND WARNING UNTIL 4 AM PST SUNDAY FOR ORZ021-ORZ022.
CA...WIND ADVISORY UNTIL 4 AM PST SUNDAY FOR CAZ081.
PACIFIC COASTAL WATERS...STORM WARNING UNTIL 4 AM PST SUNDAY FOR
PZZ350-PZZ370.
HAZARDOUS SEAS WARNING UNTIL 4 AM PST MONDAY FOR PZZ350-PZZ356-
PZZ370-PZZ376.
GALE WARNING UNTIL 4 AM PST SUNDAY FOR PZZ356-PZZ376.
$$
DDG
000
FXUS66 KMFR 220502
AFDMFR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
902 PM PST SAT NOV 21 2009
.DISCUSSION...TIGHT...RAPIDLY DEVELOPING DEEP SURFACE LOW MOVING
RAPIDLY TOWARD THE NORTHERN OREGON COAST. NAM POSITION SLIGHTLY
TO FAR NORTH AND EAST. EXPECT THE TRACK TO BE SOUTH OF NAM
FORECAST POSITION. CURRENT FORECAST TAKE THIS INTO ACCOUNT AND
LOOK GOOD. STORM FORCE WINDS ALREADY IN THE OUTER WATERS NORTH
OF THE CAPE AND WINDS SHOULD COME UP RAPIDLY IN THE NEXT 3 HOURS
ALONG THE COAST. PROGS SHOWS THE WEATHER SETTLING DOWN SUNDAY AND
MONDAY...THEN HIGH PRESSURE DOMINATING UNTIL THE END OF NEXT WEEK.
NO UPDATES NEEDED THIS EVENING.
&&
.AVIATION...CURRENT VFR CEILINGS WILL BE SHORT-LIVED AS THE
OFFSHORE FRONT DROPS CEILING TO MVFR IN LOW CLOUDS AND SHOWERS IN
THE NEXT FEW HOURS. COASTAL TERMINALS WILL LIKELY BE IMPACTED BY
LOW LEVEL WIND SHEAR WITH GUSTY WINDS TO 35KT BUT EVEN STRONGER
50-60KT WINDS JUST ABOVE THE SURFACE. STRONG WINDS WILL ALSO
IMPACT THE CASCADES AND THE EAST SIDE LATE TONIGHT AND SUNDAY
MORNING. MOUNTAINS AND EAST SIDE WILL HAVE SNOW LATE TONIGHT AND
SUNDAY MORNING...REDUCING VISIBILITIES. MOUNTAIN OBSCURATION WILL
BE WIDESPREAD BY TONIGHT THROUGH SUNDAY AS DEEP MOISTURE PUSHES
INTO THE REGION.
&&
.PREV DISCUSSION... /ISSUED 301 PM PST SAT NOV 21 2009/
DISCUSSION...QUICK-MOVING DEVELOPING FRONTAL SYSTEM WILL IMPACT
THE CWA TONIGHT THROUGH SUNDAY MORNING. THE MAIN IMPACTS WILL BE
STRONG WINDS AND SOME SNOW OVER THE CASCADES AND THE EAST SIDE.
THE FAST MOVEMENT OF THIS SYSTEM...ALONG WITH MORE WESTERLY
WINDS...WILL FAVOR THE CASCADES RECEIVING MORE SNOWFALL AND THE
MOUNT SHASTA AREA RECEIVING LESS THAN THE PREVIOUS STORM. MODELS
HAVE SETTLED ON A 990MB LOW CENTERED WEST OF THE WA/OR BORDER LATE
TONIGHT. THE STRONGEST WINDS WILL IMPACT COASTAL WATERS AND
COASTAL ZONES TONIGHT...WITH WINDS AFFECTING THE CASCADES THROUGH
THE EAST SIDE LATE TONIGHT THROUGH SUNDAY MORNING. VERY STRONG H8
FLOW OF 50KT IS NOTED OVER NORTHWESTERN PORTION OF THE CWA LATE
TONIGHT...BUT STABILITY SHOULD KEEP MOST OF THIS AREA FROM GETTING
ADVISORY LEVEL WINDS. THIS SITUATION MAY NEED TO BE LOOKED AT
DURING THE LATE AFTERNOON. SIGNIFICANT SNOW WILL FALL DURING A
SHORT PERIOD BETWEEN TONIGHT AND TOMORROW MORNING. A FOOT IS
POSSIBLE IN THE HIGHER TERRAIN OF THE CASCADES WITH SEVERAL INCHES
EXPECTED EAST OF THE CASCADES IN KLAMATH COUNTY. ON SUNDAY IN THE
POSTFRONTAL ENVIRONMENT EXPECT SNOW SHOWERS ABOVE 3500 FEET AND
RAIN SHOWERS IN THE LOWER ELEVATIONS. RIDGING WILL BUILD OVER THE
REGION SUNDAY NIGHT...ESSENTIALLY ENDING THE PRECIPITATION OVER
THE CWA.
MODELS HAVE BEEN VERY PERSISTENT WITH UPPER RIDGING FROM MONDAY
THROUGH WEDNESDAY OVER NORTHERN CA AND SOUTHWESTERN OR...WITH THE
RESULTANT WEATHER IMPACTS BEING MORNING FOG MONDAY THROUGH
WEDNESDAY IN THE FAVORED LOW ELEVATION AREAS LIKE THE ROGUE AND
ILLINOIS VALLEYS...AND THE UMPQUA BASIN. A WEAK WARM FRONT BRUSHES
THE COAST ON WEDNESDAY BUT WILL NOT LIKELY RESULT IN ANY
SIGNIFICANT PRECIPITATION. GFS AND ECMWF BOTH PUT AN END TO THE
DRY WEATHER ON THANKSGIVING DAY BUT THEIR SOLUTIONS ARE STILL
FAIRLY DIFFERENT. THERE ARE STILL UNKNOWNS REGARDING THE FORECAST
FOR THURSDAY...BUT AT THIS POINT IT SEEMS REASONABLE TO EXPECT
LIGHT SNOW IN THE MOUNTAINS AND LIGHT RAIN IN THE VALLEYS ON LATE
THURSDAY. IT STILL SEEMS THERE WILL NOT BE A LARGE STORM FOR
THANKSGIVING DAY TRAVELERS IN THE REGION.
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 7 AM PST SUNDAY FOR ORZ027-ORZ028-
ORZ029-ORZ030.
WIND ADVISORY UNTIL 7 AM PST SUNDAY FOR ORZ031.
HIGH WIND WARNING UNTIL 4 AM PST SUNDAY FOR ORZ021-ORZ022.
CA...WIND ADVISORY UNTIL 4 AM PST SUNDAY FOR CAZ081.
PACIFIC COASTAL WATERS...STORM WARNING UNTIL 4 AM PST SUNDAY FOR
PZZ350-PZZ370.
HAZARDOUS SEAS WARNING UNTIL 4 AM PST MONDAY FOR PZZ350-PZZ356-
PZZ370-PZZ376.
GALE WARNING UNTIL 4 AM PST SUNDAY FOR PZZ356-PZZ376.
$$
DDG
000
FXUS66 KPQR 220442
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
841 PM PST SAT NOV 21 2009
.SYNOPSIS...A STRONG PACIFIC COLD FRONT WILL MOVE INLAND OVERNIGHT AS
A DEEP SURFACE LOW OFF THE COAST MOVES NORTHEAST INTO WASHINGTON.
A WEAK RIDGE OF HIGH PRESSURE WILL FOLLOW SUNDAY AFTERNOON AND
NIGHT...BEFORE THE NEXT FRONTAL SYSTEM ARRIVES LATER ON MONDAY.
&&
.SHORT TERM...MODELS ARE IN REASONABLY GOOD AGREEMENT SHOWING THE
DEEP SURFACE LOW MOVING ONTO THE CENTRAL WA COAST OR POSSIBLY A BIT S
AROUND 09Z. HOWEVER AT 00Z MODELS WERE ABOUT 4 MB TOO HIGH COMPARED
WITH SHIP REPORTS W OF 130W NEAR THE LOW. MODELS ARE IN GOOD
AGREEMENT ON THE UPPER FEATURES...WITH A STRONG SHORTWAVE MOVING
ACROSS THE FORECAST AREA TONIGHT...DIGGING SLIGHTLY TO THE ESE.
TIMING OF THE COLD FRONT IN ALL MODELS INDICATES FRONTAL PASSAGE ON
THE COAST AROUND MIDNIGHT. HAVE ISSUED A HIGH WIND WARNING FOR THE
WILLAPA HILLS TO GO ALONG WITH THE COASTAL WARNING AND INLAND VALLEY
WIND ADVISORIES. WINDS INLAND LOOK GUSTY WITH THE FRONT BUT
ESPECIALLY AFTER THE FRONT AND LOW MOVE INLAND AS THERE WILL BE
STRONG PRES RISES IN THE OVERNIGHT HOURS.
DOPPLER RADAR SHOWS THE PRECIP FIELD HAS FINALLY SPREAD TO THE
CASCADES THIS EVENING. WILL CONTINUE THE WINTER STORM WARNING FOR THE
CASCADES AS MOISTURE...STRENGTH OF THE FRONT AND THE POST FRONTAL
WESTERLY OROGRAPHIC FLOW ALL FAVOR SIGNIFICANT SNOWFALL FOR LATER
TONIGHT AND SUN.
A WEAK UPPER RIDGE WILL BUILD OVER THE FORECAST AREA SUN NIGHT AND
MON FOLLOWING THE FRONT. BEST CHANCES FOR PRECIP MON AND TUE WILL
SHIFT N INTO WA WITH WARM FRONT OVERRUNNING. THE UPPER RIDGE HOLDS
COLD FRONT AT BAY UNTIL AFTER TUE NIGHT. RW
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...WEAK HIGH PRES
RIDGE OVER THE FORECAST AREA CONTINUES TO
PUSH ENERGY NORTH OF FORECAST AREA MID WEEK. IT MANAGES TO DELAY THE
ARRIVAL OF A SECOND SYSTEM THROUGH THUR. MODEL SOLUTIONS DIVERGE
TOWARD THE END OF THE WEEK AND HAVE LITTLE CONFIDENCE IN THEM. AT
THIS TIME WILL GO WITH CLIMATOLOGY UNTIL THERE IS SOME CONSISTENCY
BETWEEN THE MODELS..
&&
.AVIATION...AREAS OF MVFR CONDITIONS ALONG THE COAST THIS EVENING
WILL EXPAND INLAND TONIGHT AS THE RAIN SHIELD FROM THE NEXT STRONG
SYSTEM APPROACHES. SOUTH WINDS WILL INCREASE THROUGH 09Z AND THEN
TURN WESTERLY FROM WEST TO EAST AS THE ASSOCIATED STRONG COLD FRONT
SWINGS ACROSS THE AREA. A MIX OF VFR AND MVFR CONDITIONS ARE
EXPECTED SUNDAY MORNING IN STRONG UNSTABLE ONSHORE FLOW.
KPDX AND APPROACHES...VFR CONDITIONS ARE EXPECTED THROUGH 06Z...THEN
MVFR CONDITIONS WILL DEVELOP AS A COLD FRONT APPROACHES. SOUTH TO
SOUTHWEST WINDS MAY BECOME QUITE STRONG AROUND 12Z AS A STRONG
GRADIENT DEVELOPS OVER THE NORTH VALLEY AS THE LOW MOVES INLAND.
WIND GUSTS NEAR 50 MPH ARE POSSIBLE. A MIX OF VFR AND MVFR
CONDITIONS ARE EXPECTED SUNDAY MORNING IN STRONG UNSTABLE ONSHORE
FLOW.
&&
.MARINE...GALE FORCE SOUTH WINDS WILL STRENGTHEN TO STORM FORCE
LATER THIS EVENING AS A POTENT LOW MOVES NORTH OF THE COASTAL WATERS
AND INLAND ALONG THE WASHINGTON COAST. WINDS WILL TURN W TO NW ON
SUNDAY AND BEGIN EASING. SEAS TONIGHT WILL LIKELY PEAK AROUND 20 FT
...BUT WILL DROP QUICKLY TO THE MID TEENS ON SUN.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...STORM WARNING FOR THE COASTAL WATERS FROM CAPE SHOALWATER TO
FLORENCE THROUGH 3 AM SUNDAY MORNING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR CONDITIONS
THROUGH SUN EVENING.
WINTER STORM WARNING FOR THE S WA AND N AND CENTRAL OREGON
CASCADES TONIGHT AND SUNDAY.
HIGH WIND WARNING FOR THE S WA/N AND CENTRAL OREGON COAST...
AND WILLAPA HILLS TONIGHT.
WIND ADVISORY FOR THE WILLAMETTE VALLEY...THE LOWER
COLUMBIA...AND THE I-5 CORRIDOR FOR THIS EVENING
THROUGH SUNDAY MORNING.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KPDT 220426
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
826 PM PST SAT NOV 21 2009
.UPDATE...A DEVELOPING FRONT IS APPROACHING THE PACIFIC NORTHWEST
COAST AND WILL COME ASHORE BEFORE MIDNIGHT. RADAR ON THE WEST SIDE
OF THE CASCADES IS SHOWING SUBSTANTIAL RETURNS AND LIGHT RAIN HAS
BEEN FALLING IN PORTLAND AND SEATTLE FOR A COUPLE OF HOURS. STAMPEDE
PASS IS REPORTING MODERATE SNOW AT THIS TIME BUT AM NOT SEEING SNOW
ON ANY OF THE WEB CAMS IN THE CASCADE PASSES. EXPECT THAT
PRECIPITATION WILL BEGIN IN THE NEXT HOUR OR TWO NEAR THE CASCADE
CREST AND WORK ITS WAY ACROSS THE AREA OVERNIGHT. WINDS HAVE BEEN
LIGHT BUT RADAR VELOCITY RETURNS ARE INCREASING ON BOTH LOCAL AND
PORTLAND AND SEATTLE RADARS SHOWING THAT STRONGER WINDS WILL BE
PRESENT ALOFT BEFORE LONG. WIND PROFILER DATA SHOWS AN INCREASING
TREND AS WELL. WATER VAPOR LOOP SHOWS AN AREA OF DARKENING BEHIND
THE FRONT THAT IS INCREASING IN SIZE AND STRENGTH AS THE FRONT
DEVELOPS. ALTHOUGH WINDS WILL TAKE A FEW HOURS TO TAKE OFF...WILL
LEAVE WIND GRIDS AS IS THOUGH STRONG WINDS MAY BE SPOTTY IN COVERAGE
AT FIRST. LATEST OBSERVATIONS ARE STARTING TO SHOW SOME 15 TO 25 MPH
WINDS SO WIND FORECAST...ADVISORIES AND WARNINGS LOOK GOOD.
TEMPERATURES ARE IN MANY CASES NOT TOO FAR FROM FORECAST OVERNIGHT
LOW TEMPERATURES WHICH IS A BIT CONCERNING BUT AS SOUTH WINDS
INCREASE...TEMPERATURES SHOULD INCREASE SO WILL LEAVE FORECAST AS
IS. OVERALL...FORECAST IS IN GOOD SHAPE. NO UPDATE PLANNED. PERRY
&&
.PREV DISCUSSION... /ISSUED 332 PM PST SAT NOV 21 2009/
SHORT TERM...TONIGHT THROUGH MONDAY...THOUGHTS HAVE CHANGED LITTLE
FROM THE PREVIOUS OVERNIGHT SHIFT. MODELS REMAINED VERY CONSISTENT
WITH THE PROGRESSION OF THE SYSTEM ACROSS THE AREA. WITH A COUPLE OF
PRONOUNCED ISSUES DEALT WITH TODAY.
FIRST, DECIDED TO FOLLOW THE SURFACE LOW AS SHOWN BY THE NAM WITH
THE 18Z GFS NOW LENDING THE CLOSEST SUPPORT OF RECENT RUNS. THIS
GIVES A VERY TIGHT PRESSURE GRADIENT ACROSS MOST OF THE AREA AS THE
SURFACE LOW TRACKS ACROSS THE WASHINGTON CASCADES AND THE LOWER
COLUMBIA BASIN BEFORE LIFTING NORTHEAST LATER TOMORROW. THESE
GRADIENTS, COMBINED WITH A VERY STABLE LOWER LEVEL AIR MASS, WILL
GIVE A PROLONGED PERIOD OF STRONG WINDS ALOFT DOWN TOWARD THE
SURFACE. WILL ISSUE NUMEROUS WIND ADVISORIES AND HIGH WIND WARNINGS
AS A RESULT.
THE SECOND ISSUE DEALS WITH SNOWFALL. SNOW LEVEL WILL BE SOMEWHAT
VARIABLE WITH A BRIEF PERIOD OF WARM AIR ADVECTION AS WARM DIFFLUENT
AIR CROSSES THE CASCADES TONIGHT. THE WASHINGTON CASCADES WILL SEE
SIGNIFICANT ACCUMULATIONS MAINLY TONIGHT WITH THE MAJOR PASSES
IMPACTED. DO THINK MAINLY WESTERN AREAS WILL BEAR THE BRUNT AFTER
THE COLD FRONT PASSES LATER TONIGHT AND SUNDAY. THE BLUE MOUNTAINS
WILL START SEEING ACCUMULATIONS LATER TONIGHT AT THE HIGHER
ELEVATIONS AND PASSES BUT SNOW LEVELS WILL DROP AND ACCUMULATION
RATES WILL INCREASE MAINLY TOMORROW AFTER THE COLD FRONT PASSES AND
A NORTHWESTERLY FLOW DEVELOPS. BOTH AREAS WILL SEE SIGNIFICANT
BLOWING SNOW BUT DONT HAVE THE CONFIDENCE TO GO WITH A BLIZZARD
WARNING, BUT IT BEARS WATCHING HOWEVER.
OTHER MOUNTAIN AREAS WILL SEE SNOW AND MAYBE SOME BLOWING AS WELL,
BUT SHOULD STAY BELOW ADVISORY AMOUNTS. PRECIPITATION SHOULD BEGIN
TAPERING OFF ACROSS THE WEST BY TOMORROW AFTERNOON AND GRADUALLY
TAPER OFF ACROSS THE EAST TOMORROW EVENING. /JBONK
LONG TERM...MONDAY NIGHT THROUGH SATURDAY...A WEAK SYSTEM WILL
BREAK UP MONDAY NIGHT IT RIDES OVER A BUILDING UPPER LEVEL RIDGE.
THE BUILDING RIDGE WILL MOVE SLOWLY EAST OVER THE PACIFIC NORTHWEST
TUESDAY. THE DEPARTING SYSTEM WILL COMBINE WILL UPSLOPE FLOW IN THE
MOUNTAINS TO KEEP A SLIGHT CHANCE OF SHOWERS IN NORTHEAST OREGON
TUESDAY. ALSO...SLOPOVER PRECIPITATION MAY OCCUR NEAR THE CASCADES.
SUBSIDENCE ASSOCIATED WITH THE RIDGE WILL PROVIDE LIGHT WINDS AND
CLEARING SKIES WITH THE STRONG SURFACE INVERSIONS TUESDAY NIGHT. IN
THE LOWER COLUMBIA BASIN PATCHY FOG AND FREEZING FOG WILL FORM AT
NIGHT UNDER THE INVERSIONS AND KEEP DAYTIME TEMPERATURES WEDNESDAY
BELOW NORMAL. AT HIGHER ELEVATIONS THE SURFACE INVERSIONS WILL BREAK
DURING THE DAY AND WARMER AIR ALOFT ASSOCIATED WITH THE RIDGE WILL
REACH THE SURFACE TO PRODUCE LARGE DIURNAL TEMPERATURE SPREADS.
WEDNESDAY NIGHT THROUGH FRIDAY THERE ARE DRAMATIC DIFFERENCES
BETWEEN THE GFS AND ECMWF MODELS EVEN THOUGH BOTH HAVE SOUTHWEST
FLOW AT 500 MB. THE 0Z ECMWF HAS A MORE PROGRESSIVE PATTERN WITH A
FRONT AT AN ANGLE TO THE 500 MB FLOW THAT WILL MOVE INTO EASTERN
WASHINGTON AND OREGON AND FORM A DEFORMATION ZONE OVER THE BLUE
MOUNTAINS THAT DROPS HALF AN INCH OF RAIN THURSDAY. THE 12Z GFS HAS
THE FRONT PARALLEL TO THE 500 MB FLOW SO IT REMAINS OFFSHORE UNTIL
FRIDAY. THE GFS ENSEMBLE RUNS SHOW 500 MB FLOW RUNNING TO BOTH
EXTREMES WITH NO CLUSTERING. DECIDED TO MAKE LITTLE CHANGE TO
EXISTING FORECAST WITH A CHANCE OF POPS MOST PLACES AND LIKELY POPS
OVER THE MOUNTAINS. THINK ECMWF IS OVERBLOWN WITH AMOUNT OF
PRECIPITATION UNLESS THE DEFORMATION BAND DOES SET UP...BUT DID
TREND TOWARD IT BY KEEPING AT LEAST A CHANCE OF POPS ACROSS THE
AREA. WHEN THE 12Z RUN OF THE ECMWF ARRIVED IT WAS SLOWER WITH NO
DEFORMATION BAND...BUT IT STILL SUPPORTED THE FASTER ARRIVAL OF THE
FRONT DURING THE DAY THURSDAY. BOTH MODELS HAD PRECIPITATION FRIDAY
WITH THE GFS PUSHING THE FRONT THROUGH AND THE ECMWF MOVING THE
UPPER LEVEL TROUGH THROUGH. WITH LOW CONFIDENCE DUE TO MODEL
DIFFERENCES KEPT A LOW CHANCE POPS ACROSS THE AREA SATURDAY.
COONFIELD
AVIATION...0Z TAFS...VFR CONDITIONS WILL PREVAIL IN MOST AREAS
THROUGH 04Z WITH BROKEN MID LEVEL CEILINGS. ANOTHER PACIFIC WEATHER
SYSTEM WILL MOVE INTO THE AREA TONIGHT AND EARLY SUNDAY MORNING WITH
RAIN AND MOUNTAIN SNOW. THIS WILL CAUSE AREAS OF MVFR CONDITIONS.
IFR WITH POSSIBLY EVEN LIFR CONDITIONS IN LOCAL AREAS WITH RAIN AND
SNOW...ESPECIALLY NEAR ANY MOUNTAIN RANGES OR OVER THE CENTRAL
OREGON PLATEAUS NEAR TAF SITE KRDM. WINDS OF 10 TO 20 KTS WITH GUSTS
TO 30 KTS FROM THE SOUTHWEST WILL BE COMMON IN ALL AREAS TODAY.
HOWEVER THE WINDS WILL INCREASE OVERNIGHT TONIGHT AS PRESSURE
GRADIENTS TIGHTEN UP AHEAD OF THE NEXT WEATHER SYSTEM. DURING THAT
TIME WINDS ARE EXPECTED TO INCREASE TO AT LEAST 15 TO 25 KTS WITH
GUSTS TO 40 KTS OR POSSIBLY EVEN HIGHER INTO SUNDAY. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 41 47 31 43 / 80 70 10 10
ALW 39 48 32 43 / 90 80 10 10
PSC 37 51 30 44 / 90 50 10 10
YKM 32 45 29 44 / 90 40 10 10
HRI 38 49 29 45 / 80 50 10 10
ELN 34 39 26 39 / 90 70 10 20
RDM 35 45 24 47 / 80 40 10 10
LGD 36 42 23 40 / 80 80 20 10
GCD 34 41 21 44 / 70 60 10 10
DLS 37 49 32 47 / 80 40 20 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 10 AM PST SUNDAY FOR ORZ049-050.
WINTER STORM WARNING UNTIL 7 PM PST SUNDAY FOR ORZ502.
HIGH WIND WARNING FROM 1 AM TO 4 PM PST SUNDAY FOR ORZ042.
WIND ADVISORY UNTIL 1 PM PST SUNDAY FOR ORZ043.
WIND ADVISORY UNTIL 7 PM PST SUNDAY FOR ORZ501-504.
WINTER WEATHER ADVISORY UNTIL 7 PM PST SUNDAY FOR ORZ503.
WIND ADVISORY FROM 4 AM TO 4 PM PST SUNDAY FOR ORZ041-044.
WA...WINTER WEATHER ADVISORY UNTIL 4 PM PST SUNDAY FOR WAZ501-502.
WINTER STORM WARNING UNTIL 7 PM PST SUNDAY FOR WAZ030.
WIND ADVISORY UNTIL 7 PM PST SUNDAY FOR WAZ029.
WIND ADVISORY FROM 4 AM TO 4 PM PST SUNDAY FOR WAZ024-028.
&&
THREAT INDEX
SUNDAY : RED
MONDAY : GREEN
TUESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/76/76
000
FXUS65 KBOI 220339
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
838 PM MST SAT NOV 21 2009
.DISCUSSION...THE LATEST DATA AND NAM MODEL RUN FIT FORECAST TRENDS
WELL...SO NOT PLANNING ON MAKING ANY CHANGES THIS EVENING. WILL...
HOWEVER...UPDATE THE WINTER WEATHER BULLETIN TO INCLUDE THE UPPER
WEISER RIVER ZONE 33. MOST OF THE SNOWFALL...WHICH WILL BE LOCALLY
HEAVY IN THE MOUNTAINS...WILL OCCUR IN A 3-6 HOUR PERIOD IN THE WARM
SECTOR AHEAD OF THE FRONT...STARTING LATE TONIGHT IN SE OREGON
ENDING IN SW IDAHO EARLY SUNDAY AFTERNOON. THE SNOW WILL TAPER OFF
TO SNOW SHOWERS AFTER THE COLD FRONT MOVES THROUGH PROVIDING
ADDITIONAL LIGHT SNOW ACCUMS. WINDS WILL INCREASE AS WELL AND
COMBINE WITH THE SNOWFALL FOR AREAS OF BLOWING AND DRIFTING SNOW.
&&
.AVIATION...THICKENING AND LOWERING CLOUDS TONIGHT. WIDESPREAD
MOUNTAIN OBSCURATION AND IFR CONDITIONS IN SNOW SHOWERS DEVELOPING
OVER SOUTHEAST OREGON AFTER 09Z AND SOUTHWEST IDAHO AFTER 12Z. IFR
CONDITIONS WILL CONTINUE IN SOUTHWEST IDAHO MOUNTAINS AND WESTERN
MAGIC VALLEY THROUGH SUNDAY AFTERNOON. CONDITIONS WILL IMPROVE TO
VFR IN SOUTHEAST OREGON AND THE TREASURE VALLEY OF SOUTHWEST IDAHO
BY SUNDAY AFTERNOON. GUSTY SOUTHEAST SURFACE WINDS TONIGHT WILL
SHIFT TO THE WEST BY SUNDAY AFTERNOON. WINDS ALOFT WILL BE STRONG
FROM THE NORTHWEST.
&&
.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH MONDAY...WINDS WILL BUILD TONIGHT FROM
THE SOUTHEAST AND SOUTH THEN SHIFT TO SW AND NW SUNDAY BEHIND A FAST
MOVING COLD FRONT. HUGE..IE...-4/-6 TO +10/+15 MB PRESSURE FALL/RISE
COUPLET STAYS TO OUR NW AND N FOR LOCALLY VERY WINDY CONDITIONS
ACROSS SE OREGON AND BREEZY AREAS FOR SW IDAHO...BUT NO HEADLINES
FOR WIND. SNOW AND AREAS OF BLOWING/DRIFTING SNOW ARE EXPECTED WITH
THIS FAST MOVING SYSTEM SUNDAY SO AN ADVISORY FOR SNOW AND BLOWING
SNOW HAS BEEN HOISTED ACROSS BAKER COUNTY...THE WEST CENTRAL AND
BOISE MOUNTAINS. GUSTY NW WINDS DIMINISH RAPIDLY MONDAY NIGHT AS
HIGH PRESSURE BUILDS IN...WITH LIGHT WINDS AND MOSTLY CLEAR SKIES.
COUPLED WITH NEW SNOW COVER...GENERALLY ABOVE 3500 FEET...LOW TEMPS
WILL PLUMMET TO SINGLE DIGITS COLDEST SPOTS SUCH AS FAIRFIELD AND
MID 20S...TEENS ACROSS THE RELATIVELY MILDER LOCALES. LIGHT WINDS
AND A COLD START MONDAY LOOK TO KEEP TEMPS BELOW NORMAL AND NEAR TO
BELOW MOS.
LONG TERM...MONDAY NIGHT THROUGH SATURDAY...UPPER RIDGE BUILDS INTO
THE PACIFIC NW ON TUESDAY. WEAK SYSTEM MOVING THROUGH THE PANHANDLE
TUESDAY AFTERNOON WILL DO LITTLE MORE THAT INCREASE CLOUDS OVER THE
WEST CENTRAL MTNS. WITH WARMING ALOFT...INVERSION SETS UP IN THE
LOWER ELEVATIONS FOR TUE/WED. INTRODUCED FOG INTO THE FORECAST FOR
TUESDAY NIGHT AND WEDNESDAY IN THE LOWER TREASURE...WEISER AND BAKER
VALLEYS. LESS CONFIDENT ON DEVELOPMENT OF FOG/STRATUS OVER BOISE
WEDNESDAY MORNING SO HAVE LEFT IT OUT FOR NOW. GOOD MODEL AGREEMENT
THAT INVERSION IS SHORT-LIVED...AS ANOTHER STORM ENTERS THE PAC NW
LATE IN THE WEEK. THE 12Z SOLUTIONS ARE IN BETTER AGREEMENT ON
BRINGING THE STORM THROUGH THE INTERMOUNTAIN NW ON FRIDAY. WINDS
AHEAD OF THE SYSTEM WOULD LIKELY CLEAR OUT ANY FOG/STRATUS IN THE
LOWER VALLEYS THANKSGIVING DAY. LOOKS LIKE RAIN IN THE VALLEYS ON
FRIDAY WITH MTN SNOW. PATTERN REMAINS ACTIVE THROUGH NEXT WEEKEND.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...WINTER WEATHER ADVISORY FROM 4 AM TO 2 PM MST SUNDAY FOR IDZ033.
WINTER WEATHER ADVISORY FROM 4 AM TO 2 PM MST SUNDAY FOR IDZ011-
IDZ013.
OR...WINTER WEATHER ADVISORY FROM 1 AM TO 10 AM PST SUNDAY FOR
ORZ062.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...BW
AVIATION.....JA
PREV SHORT TERM...VM
PREV LONG TERM....DG/DD
| 
