[top]
000
FXUS65 KSLC 231142
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
442 AM MST MON NOV 23 2009
.SYNOPSIS...HIGH PRESSURE ALOFT WILL STRENGTHEN ACROSS THE REGION
THROUGH MID-WEEK. A PACIFIC STORM SYSTEM IS EXPECTED TO SPREAD
INTO THE REGION LATE IN THE WEEK INTO THE UPCOMING WEEKEND.
&&
.DISCUSSION...STORM SYSTEM WHICH BROUGHT WIDESPREAD SNOWFALL TO A
GOOD PORTION OF NORTHERN UTAH SUNDAY AFTERNOON AND EVENING
CONTINUES TO PROPAGATE EASTWARD INTO THE CENTRAL HIGH PLAINS THIS
MORNING. ASSOCIATED COLD FRONT HAS PUSHED THROUGH THE FORECAST
AREA...WITH SURFACE HIGH PRESSURE CENTERED ACROSS THE EASTERN
GREAT BASIN. WARMING ALOFT HAS STABILIZED THE AIRMASS CONSIDERABLY
ACROSS NORTHERN UT WHICH HAS GREATLY DIMINISHED SNOW SHOWER
ACTIVITY DOWNSTREAM FROM THE GSL. ALLOWED GOING WINTER WX ADVISORY
TO EXPIRE AS SCHEDULED AT 4AM...WITH ANY LINGERING SNOW SHOWERS
LIKELY DISSIPATING BY SUNRISE.
MODELS ARE IN GENERAL AGREEMENT AMPLIFYING A MID LEVEL RIDGE
ACROSS THE REGION THROUGH THE MIDDLE PORTION OF THE WEEK. WARMING
ALOFT COMBINED WITH SNOW ON THE GROUND AND LOW SUN ANGLE WILL ALL
CONTRIBUTE TO STRENGTHENING VALLEY INVERSIONS ACROSS MUCH OF
NORTHERN AND CENTRAL UT THROUGH THIS TIME...WHILE WARMING ALOFT
WILL BE MORE NOTICEABLE AT HIGHER ELEVATIONS.
MEDIUM RANGE MODELS ADVERTISE A FAIRLY DISORGANIZED MID LEVEL
TROUGH TO MOVE INTO THE REGION LATE IN THE WEEK AND INTO THE
UPCOMING WEEKEND. HOWEVER DIFFERENCES ABOUND WITH RESPECT TO HOW
THIS TROUGH WILL EVOLVE AS IT PASSES THROUGH THE REGION AND
TIMING/TRACK OF INDIVIDUAL SHORTWAVE FEATURES. AS A RESULT
TRENDED POPS UP TO CLIMO OR SLIGHTLY ABOVE FROM FRIDAY ON.
&&
.AVIATION...CEILINGS AT THE SLC TERMINAL WILL REMAIN BETWEEN 4500
AND 6500 FEET THROUGH 17Z WITH A 30 PERCENT CHANCE OF BREAKING INTO
A SCATTERED LAYER BY 15 TO 16Z WHILE THERE IS A 10 PERCENT CHANCE OF
CEILINGS LASTING THROUGH 20Z. NO OTHER FORECAST ISSUES OF CONCERN.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&
$$
SEAMAN/STRUTHWOLF
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
000
FXUS65 KSLC 230340
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
840 PM MST SUN NOV 22 2009
.SYNOPSIS...A STORM SYSTEM WILL CONTINUE TO IMPACT THE AREA THROUGH
TONIGHT. HIGH PRESSURE ALOFT WILL THEN SETTLE OVER UTAH MONDAY
NIGHT...AND REMAIN OVER THE REGION THROUGH THE BALANCE OF THE WEEK.
&&
.DISCUSSION...A STORM SYSTEM CONTINUES TO MOVE ACROSS THE REGION
THIS EVENING. THE CLOSED UPPER LOW ASSOCIATED WITH THIS SYSTEM IS
CURRENTLY NOTED NEAR THE IDAHO/MONTANA BORDER WITH THE UPPER JET
DIVING ACROSS CENTRAL UTAH. THE ASSOCIATED COLD FRONT HAS MOVED TO
NEAR A MILFORD-PRICE-ROCK SPRINGS LINE AND WILL CONTINUE TO SWEEP
ACROSS SOUTHEAST UTAH THROUGH AROUND MIDNIGHT.
SNOWFALL DEVELOPED OVER NORTHERN UTAH/SOUTHWEST WYOMING THIS EVENING
AHEAD OF AND BEHIND THE FRONT...BUT THIS HAS ALREADY DECREASED IN
INTENSITY AS THE 700MB BAROCLINIC ZONE PUSHED SOUTH. DUE TO THE
POSITION OF THE JET...EXPECT PRECIPITATION TO REMAIN LIMITED TO
MAINLY THE NORTHERN HALF OF THE CWA. WITH PRECIPITATION WINDING DOWN
FOR THE MOST PART...EXPECT ONLY MINOR ADDITIONAL ACCUMULATIONS
THROUGH THE REMAINDER OF THE NIGHT BEFORE THE STORM SYSTEM MOVES
EAST OF THE AREA AND THE AIRMASS BECOMES MORE STABLE BY EARLY
TOMORROW MORNING. THE ONLY WILD CARD WILL BE THE LAKE. AT THIS
TIME...700MB TEMPERATURES OF -12C OVER LAKE TEMPERATURES OF +8C
SHOULD RESULT IN ENOUGH INSTABILITY FOR SOME LAKE-INDUCED SHOWERS TO
DEVELOP TONIGHT THROUGH AROUND 09Z...AND IT APPEARS THAT THESE
SHOWERS ARE ALREADY BEGINNING. LATEST BUFR SOUNDINGS INDICATE THESE
SHOWERS COULD IMPACT ANYWHERE FROM SOUTHERN DAVIS/NORTHEAST SALT
LAKE COUNTY TO THE CENTRAL SALT LAKE VALLEY...INCLUDING THE SALT
LAKE AIRPORT. WILL HAVE TO WATCH ITS DEVELOPMENT THIS EVENING TO SEE
IF ANY ADDITIONAL HEADLINES ARE NECESSARY. OTHERWISE...AM
CONSIDERING CANCELING THE ADVISORY FOR THE CACHE VALLEY LATER
TONIGHT...BUT KEEP THE MOUNTAIN ZONES GOING. AS FOR THE NORTHERN
WASATCH FRONT...WILL WAIT AND SEE IF THIS AREA WILL BE IMPACTED BY
THE LAKE-EFFECT.
HIGH PRESSURE WILL BUILD INTO THE AREA BEHIND THE DEPARTING LOW
TOMORROW AND THEN REMAIN IN PLACE THROUGH MUCH OF THE WEEK.
&&
.AVIATION...WINDS AT THE SLC TERMINAL ARE EXPECTED TO REMAIN
NORTHERLY THROUGH AROUND 12Z...BEFORE BECOMING SOUTHEASTERLY BETWEEN
11Z AND 15Z. HOWEVER...THERE IS A 30 PERCENT CHANCE THAT WINDS COULD
SHIFT TO THE SOUTHEAST AS EARLY AS 9Z. MVFR CONDITIONS ARE EXPECTED
TO SLOWLY IMPROVE TO VFR BETWEEN 6Z AND 9Z...BUT COULD LAST AS LONG
AS 12Z DEPENDING ON LAKE EFFECT SNOW. CEILINGS BELOW 6000 FEET ARE
EXPECTED THROUGH AROUND 15Z.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...WINTER WEATHER ADVISORY UNTIL 4 AM MONDAY FOR UTZ007-UTZ009.
WINTER WEATHER ADVISORY UNTIL 4 AM MONDAY FOR UTZ001-UTZ002.
WY...NONE.
&&
$$
PUBLIC...CHENG
AVIATION...HOSENFELD
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
000
FXUS65 KSLC 222258
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
358 PM MST SUN NOV 22 2009
.SYNOPSIS...A COLD FRONT WILL SWEEP ACROSS UTAH TONIGHT. HIGH
PRESSURE ALOFT WILL SETTLE OVER UTAH MONDAY NIGHT...AND REMAIN
OVER THE REGION THROUGH THE BALANCE OF THE WEEK.
&&
.DISCUSSION...THE SURFACE COLD FRONT JUST OFF THE NW CORNER OF
UTAH WILL SWEEP SE ACROSS THE STATE OVERNIGHT. THE ASSOCIATED
UPPER TROUGH BACK ACROSS WRN ID WILL MOVE QUICKLY TO THE E-SE...
DRIVING THE SURFACE FRONT THROUGH THE STATE WHILE JUST CLIPPING
THE FAR NRN PORTION UTAH AND SW WYOMING LATER THIS EVENING. THE
BEST THREAT FOR WIDESPREAD/LOCALLY HEAVY SNOWFALL WILL REMAIN
CLOSE TO THE UPPER TROUGH WHERE THE BEST COMBINATION OF LOW-LEVEL
COLD ADVECTION...DYNAMIC LIFT AND DEEP LAYER MOISTURE/INSTABILITY
WILL EXIST. WILL MAINTAIN THE LOW-END SNOW ADVISORIES FOR THE NRN
WASATCH RANGE AND WRN UINTAS...AND ADD THE ADJACENT NRN WASATCH
FRONT/CACHE VALLEY TONIGHT.
HIGH PRESSURE ALOFT WILL DEVELOP IMMEDIATELY BEHIND THE EXITING
TROUGH...AND REMAIN THE DOMINATE FEATURE THROUGH AT LEAST EARLY
FRIDAY. HIGH ELEVATION LOCATIONS WILL SEE A WARMING/DRYING TREND
THIS WEEK...WITH THE VALLEY TEMPS CLIMBING A BIT MORE SLOWLY DUE
TO STRENGTHENING INVERSIONS.
MODEL GUIDANCE DOES SHOW AN UPPER TROUGH CRASHING INTO THE WRN
STATES RIDGE EITHER LATE FRIDAY OR FRIDAY NIGHT. LATEST GUIDANCE
OFFERS AS MANY SOLUTIONS AS THERE ARE AVAILABLE MODELS...SO
CONFIDENCE WITH ANYONE OF THEM LOW RIGHT NOW. WOULD SUSPECT THAT
ANY SYSTEM RUNNING INTO A STRONG RIDGE WOULD WEAKEN...SO THE
CANADIAN MODELS SEEMS TO BE OUT OF THE PICTURE. THE ECMWF AND GFS
BOTH OFFER A WEAKEN SYSTEM...AND WILL PROBABLY HAVE THE BEST
CHANCE OF VERIFYING OVER TIME.
&&
.AVIATION...WINDS AT THE SLC TERMINAL ARE EXPECTED TO REMAIN FROM
THE NORTHWEST OVERNIGHT...BUT MAY BRIEFLY BECOME SOUTHEASTERLY
BETWEEN 11Z AND 15Z. VFR CONDITIONS ARE EXPECTED TO DROP INTO THE
MVFR RANGE IN SNOW BETWEEN 02Z AND 07Z...AND MAY BRIEFLY DIP INTO
THE IFR RANGE IN HEAVIER SNOW. CEILINGS BELOW 6000 FEET ARE EXPECTED
THROUGH AROUND 15Z.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...WINTER WEATHER ADVISORY UNTIL 4 AM MONDAY FOR UTZ007-UTZ009.
WINTER WEATHER ADVISORY UNTIL 4 AM MONDAY FOR UTZ001-UTZ002.
WY...NONE.
&&
$$
PUBLIC...CONGER
AVIATION...HOSENFELD
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
000
FXUS65 KSLC 221625
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
925 AM MST SUN NOV 22 2009
.SYNOPSIS...THE NEXT PACIFIC STORM SYSTEM WILL CLIP NORTHERN UTAH
TONIGHT THROUGH EARLY MONDAY MORNING. HIGH PRESSURE ALOFT WILL SETTLE
OVER UTAH FOR MONDAY NIGHT THROUGH EARLY FRIDAY.
&&
.DISCUSSION...THE COLD CORE UPPER TROUGH CURRENTLY OVER THE PACIFIC
NW WILL RACE EAST INTO THE NRN ROCKIES/NRN GREAT BASIN LATER TODAY.
THIS TROUGH WILL MAKE A TURN TO THE E-SE TONIGHT...CLIPPING THE
NRN PORTION OF UTAH OVERNIGHT. THE ASSOCIATED SURFACE COLD FRONT
WILL MOVE INTO WRN IDAHO LATE THIS MORNING...THEN MOVE QUICKLY
E-SE INTO NW UTAH LATE THIS AFTERNOON. FROM THERE THE FRONT WILL
SWEEP SE ACROSS THE STATE...EXITING UTAH EARLY MONDAY.
LOOKING AT THE BEST ORGANIZED PRECIP TO REMAIN BEHIND THE COLD
FRONT OVER FAR NRN UTAH TONIGHT. A WELL-DEFINED SURFACE FRONT
WITH SOLID LOW-LEVEL COLD ADVECTION UP TO NEAR 600MB WILL SWEEP
INTO CNTRL UTAH THIS EVENING. THE COLD ADVECTION LOOKS TO GET
SHALLOWER AS THE FRONT MOVES INTO SRN UTAH LATE TONIGHT. THE MID-
LEVEL COLD AIR DOES NOT FOLLOW THE FRONT SOUTH...REMAINING NEAR
THE UT/ID BORDER AS THE TROUGH RACES OFF TO THE E-SE. WILL LOOK AT
THE BEST LIFT CONFINED TO FAR NRN UTAH IN POST-FRONTAL AREAS NEAR
THE MID-LEVEL COLD AIR AND BEST DYNAMIC LIFT. CURRENT SNOW
ADVISORY FOR THE FAR NRN/NERN MOUNTAINS LOOKS FINE FOR A LOW-END
EVENT. THE CNTRL/SRN WASATCH RANGE LIKELY TO SEE MORE OF A SHORT
INTENSE EVENT WITH SUB-ADVISORY AMOUNTS EXPECTED.
HIGH PRESSURE ALOFT TO BE THE DOMINATE FEATURE THROUGH THE COMING
WEEK. DRY/STABLE CONDITIONS WITH A WARMING TREND AT THE HIGHER
ELEVATIONS WILL BE THE RULE...WITH THE VALLEYS RESPONDING MORE
SLOWLY DUE TO THE TIGHTENING INVERSIONS. AREAS OF THE FAR NORTH
THAT DO PICK UP SOME SNOW TONIGHT MAY SEE A STATIC TEMPERATURE TREND
THIS WEEK.
NO UPDATES PLANNED THIS MORNING.
&&
.AVIATION...SOUTHEAST WINDS WILL GRADUALLY INCREASE THROUGH THE
DAY AT KSLC AHEAD OF AN APPROACHING COLD FRONT. THIS FRONT IS
EXPECTED TO REACH THE TERMINAL BETWEEN 22Z AND 00Z. MVFR
CONDITIONS BEHIND THE COLD FRONT WITH OCCASIONAL IFR DUE TO
CEILINGS AND VISIBILITIES IN HEAVIER SNOW POSSIBLE BETWEEN 00-06Z.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...WINTER WEATHER ADVISORY FROM 4 PM SUNDAY TO 4 AM MONDAY FOR
UTZ007-UTZ009.
WY...NONE.
&&
$$
PUBLIC...CONGER
AVIATION...YOUNG
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
000
FXUS65 KSLC 221003
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
303 AM MST SUN NOV 22 2009
.SYNOPSIS...THE NEXT PACIFIC STORM SYSTEM WILL CROSS THE NORTHERN
HALF OF UTAH TONIGHT THROUGH EARLY MONDAY. HIGH PRESSURE
ALOFT WILL SETTLE OVER UTAH FOR MONDAY NIGHT THROUGH THURSDAY.
&&
.DISCUSSION...WATER VAPOR LOOP SHOWS A COMPACT AND ENERGETIC WAVE
QUICKLY APPROACHING THE OREGON COAST...WITH WEAK RIDGING DEVELOPING
OVER THE GREAT BASIN. 400-250MB ACARS WIND OBSERVATIONS PLACES AN
UPPER LEVEL TROUGH AXIS OVER THE ROCKIES...WITH A 60-100KT JET
ENTERING THE BASE OF THE TROUGH FROM THE PACIFIC NORTHWEST. 00Z
700MB ANALYSIS SHOWS A COLD FRONT CROSSING SOUTHERN UTAH. COLD
ADVECTION IS OCCURRING LOCALLY...WITH -10C AT KSLC AND -11C UPSTREAM
AT KLKN. 00Z KSLC RAOB INDICATES 10 TO 15C OF COOLING THROUGH THE
COLUMN DURING THE PAST 24 HOURS.
GOES/RUC PRECIPITABLE WATER INDICATE VALUES REMAIN BETWEEN A TENTH
AND A QUARTER INCH ACROSS THE STATE.
MODEL SUITE CONSISTING OF THE NAM/GFS/CANADIAN/EUROPEAN ARE MORE IN
LINE REGARDING THE TRACK AND TIMING OF THE UPCOMING SYSTEM. THE WAVE
CROSSING INTO WESTERN OREGON HAS A VERY ORGANIZED PRESENTATION ON
WATER VAPOR...THOUGH IS TREKKING ALONG VERY QUICKLY.
NEVERTHELESS...ONCE THE COLD FRONT ARRIVES BY EARLY EVENING...A
QUICK BURST OF SNOWFALL CAN BE EXPECTED ACROSS THE NORTHERN
MOUNTAINS...WITH ACCUMULATIONS DOWN TO THE VALLEY FLOOR ACROSS
NORTHERN UTAH.
THE POPS IN THE FORECAST THIS AFTERNOON ARE EXPECTED TO BE REALIZED
AT THE TAIL END OF THE PERIOD JUST BEFORE SUNSET. THROUGH THE
MORNING HOURS...EXPECT A BAND OF MID AND HIGH LEVEL CLOUDS TO
TRAVERSE EAST ACROSS THE FORECAST AREA IN ASSOCIATION WITH WARMING
ALOFT. BREAKS OF SUNSHINE CAN BE EXPECTED...ESPECIALLY ACROSS
CENTRAL AND SOUTHERN UTAH TODAY. WARM ADVECTION AT 700MB WILL
SUPPORT SIMILAR OR SLIGHTLY HIGHER TEMPERATURES ACROSS SOUTHERN AND
CENTRAL UTAH TODAY...THOUGH HAVE UNDERCUT GUIDANCE ACROSS THE CACHE
VALLEY AND SEVERAL OTHER NORTHERN VALLEYS WHERE THE FEELING IS FULL
MIXING WILL NOT BE ACHIEVED TODAY.
THE COLD FRONT IS EXPECTED TO CROSS NORTHWEST UTAH THIS AFTERNOON
AND ARRIVE ALONG THE WASATCH FRONT BY SUNSET...BEFORE BLASTING
THROUGH MUCH OF THE STATE THROUGH MIDNIGHT. THIS TIMING PLACES THE
BEST BURST OF PRECIPITATION DURING THE EVENING HOURS. THE LIMITING
FACTOR CONCERNING SNOW AMOUNTS IS THE SPEED OF THE SYSTEM...WITH MID
LEVELS WARMING BEGINNING ABOUT MIDNIGHT. THE COLD CORE ALOFT (ON THE
ORDER OF -24 TO -26C) IS SHOWN TO PASS OVER FAR NORTHERN UTAH AND
SOUTHWEST WYOMING OVERNIGHT. GIVEN THIS TRACK AND TIMING...THE
NORTHERN WASATCH MOUNTAINS AND FAR WESTERN UINTA MOUNTAINS STAND THE
BEST CHANCE OF SIGNIFICANT ACCUMULATIONS...WITH SNOW TOTALS
GENERALLY DECREASING FURTHER SOUTH. VALLEY ACCUMULATIONS ARE
EXPECTED ACROSS THE CACHE...NORTHERN WASATCH FRONT AND WASATCH
MOUNTAIN VALLEYS...THOUGH ACCUMULATIONS SHOULD BE LIMITED BY THE
SPEED OF THE SYSTEM. THE SALT LAKE VALLEY CAN EXPECT MINOR
ACCUMULATIONS...WITH SOME BENCH LOCATIONS AND THE WEST END OF THE
VALLEY HAVING THE POTENTIAL OF SEEING UP TO 2 INCHES.
WITH 700MB TEMPERATURES FORECAST TO DIP TO -12C AT 700MB BY LATE
EVENING...NEED TO ADDRESS POSSIBILITY OF LAKE EFFECT SNOWFALL. THE
AVHRR SENSOR SHOWS THE GREAT SALT LAKE WATER TEMPERATURES HAVE
COOLED TO +8C. WITH THE -13C 700MB TEMPERATURES BY MONDAY
MORNING...THE 00Z NAM SUGGESTS BETWEEN 300-500 J/KG OF LAKE INDUCED
CAPE WITH EQUILIBRIUM LEVELS AT BETWEEN 10-12KFT. THESE VALUES ARE
NOT AS FAVORABLE AS THE LAST SIGNIFICANT LAKE EFFECT SETUP...THOUGH
ARE HIGH ENOUGH TO WARRANT GREATER POPS/QPF/SNOWFALL ACROSS THE WEST
END OF THE SALT LAKE VALLEY TONIGHT. THE WINDOW FOR LAKE EFFECT SNOW
IS LIMITED BY THE WARMING ALOFT EXPECTED DURING THE SECOND HALF OF
TONIGHT.
THE AFFECT OF THIS SYSTEM WILL WANE ACROSS THE REGION LATE TONIGHT
INTO MONDAY MORNING AS THE MID LEVEL SYSTEM DEEPENS ACROSS THE
CENTRAL ROCKIES AND HIGH PLAINS. OVERNIGHT LOWS DURING THE EARLY
WORK WEEK LOOK QUITE CHILLY.
RIDGING AT 700MB IS EXPECTED TO BUILD INTO THE REGION FROM THE
SOUTHWEST CONUS THROUGH THE MID WEEK...WITH THE NEXT SYSTEM
APPROACHING FROM THE PACIFIC NORTHWEST LATE DURING THE WORK WEEK.
EXPECT TO SEE PLENTY OF SUNSHINE AS TEMPERATURES WARM TO...THEN
ABOVE CLIMATOLOGY NEXT WEEK.
&&
.AVIATION...SOUTH WINDS WILL GRADUALLY INCREASE THOUGH THE MORNING
AND EARLY AFTERNOON HOURS AT KSLC AHEAD OF AN APPROACHING COLD
FRONT. THIS FRONT IS EXPECTED TO REACH THE TERMINAL DURING THE
22-00Z TIME FRAME. OCCASIONAL IFR CIGS/VIS IN SNOW POSSIBLE BETWEEN
00-06Z.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...WINTER WEATHER ADVISORY FROM 4 PM SUNDAY TO 4 AM MONDAY FOR
UTZ007-UTZ009.
WY...NONE.
&&
$$
PUBLIC...ROGOWSKI
AVIATION...SEAMAN
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
000
FXUS65 KSLC 220415
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
915 PM MST SAT NOV 21 2009
.SYNOPSIS...THE NEXT PACIFIC STORM SYSTEM WILL CROSS THE NORTHERN
HALF OF UTAH SUNDAY NIGHT THROUGH EARLY MONDAY. HIGH PRESSURE
ALOFT WILL SETTLE OVER UTAH FOR MONDAY NIGHT THROUGH THURSDAY.
&&
.DISCUSSION...SKIES ARE CLEARING ACROSS THE FORECAST AREA THIS
EVENING AS TODAYS SHORTWAVE EXITS THE AREA...WITH ONLY SOME HIGH
CLOUDS EXPECTED TO MOVE INTO THE NORTHERN HALF OF THE CWA
OVERNIGHT. THE BREAK BETWEEN SYSTEMS WILL BE A BRIEF ONE...AS THE
NEXT SHORTWAVE WILL MOVE INTO THE CWA TOMORROW AFTERNOON. THE
MODELS HAVE FINALLY COME INTO SOME AGREEMENT ABOUT THIS
SYSTEM...WITH THE FINAL CONSENSUS SOLUTION BEING CLOSER TO THE
ONE THAT THE GFS HAS BEEN PROMOTING THE PAST FEW DAYS. THIS WAS
THE FURTHEST NORTH AND WEAKEST SOLUTION...WITH THE
ECMWF...NAM...AND CANADIAN MODEL ALL BACKING OFF FROM THE SLIGHTLY
MORE ROBUST TROUGH THEY HAD PREVIOUSLY FORECAST. THE SHORTWAVE
IS EXPECTED TO MOSTLY BRUSH BY NORTHERN UTAH AND SOUTHWEST
WYOMING...WITH THE BEST CHANCE FOR PRECIP BEING BETWEEN 00Z AND
06Z MONDAY...PARTICULARLY IN THE MOUNTAINS OF NORTHERN UTAH.
NORTHWESTERLY FLOW WILL SETTLE OVER THE CWA ON MONDAY AS THE
TROUGH EXITS THE REGION. FOR MOST OF THE REST OF THE WORK WEEK...A
RIDGE WILL BUILD OVER THE WESTERN CONUS...WITH A DRY AND STABLE
AIRMASS OVER OUR CWA. THIS RIDGE IS EXPECTED TO HOLD THROUGH
THURSDAY. BEYOND THAT...ALL OF THE MAJOR GLOBAL MODELS HAVE SOME
SORT OF TROUGH ENTERING THE GREAT BASIN ON FRIDAY.
HOWEVER...THE SOUTHERN EXTENT OF THIS TROUGH VARIES AMONG THE
MODELS...WITH THE GFS BEING THE DRIEST OF THE THREE...PRODUCING
YET ANOTHER BRUSH-BY FOR NORTHERN UTAH SIMILAR TO THE CURRENT
ONGOING PATTERN.
THE FORECAST FOR TONIGHT LOOKS GOOD AND NO UPDATES ARE PLANNED
FOR THIS EVENING.
&&
.AVIATION...NORTHWEST WINDS AT THE SLC TERMINAL WILL GRADUALLY SHIFT
TO THE SOUTHEAST DRAINAGE BETWEEN 04Z AND 06Z. WINDS WILL THEN
SLOWLY INCREASE TOMORROW AS THE COLD FRONT MOVES TOWARDS UTAH. VFR
CONDITIONS WILL PREVAIL.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&
$$
PUBLIC...SCHOENING
AVIATION...YOUNG
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
000
FXUS65 KSLC 212309
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
409 PM MST SAT NOV 21 2009
.SYNOPSIS...THE NEXT PACIFIC STORM SYSTEM WILL CROSS THE NORTHERN
HALF OF UTAH SUNDAY NIGHT THROUGH EARLY MONDAY. HIGH PRESSURE
ALOFT WILL SETTLE OVER UTAH FOR MONDAY NIGHT THROUGH THURSDAY.
&&
.DISCUSSION...A WEAK VORTICITY MAX ALONG THE NW UT/NE NV BORDER
WILL RACE EAST THROUGH NRN UTAH EARLY THIS EVENING. LIGHT SHOWERS
ASSOCIATED WITH THIS FEATURE SHOULD END EARLY THIS EVENING...
FOLLOWED BY A WEAK SHORTWAVE RIDGE LATE TONIGHT THROUGH EARLY
SUNDAY.
THE NEXT PACIFIC TROUGH WILL MOVE INTO NRN UTAH BY EARLY SUNDAY
EVENING...THEN RACE SE INTO COLORADO BY EARLY MONDAY MORNING. THE
LATEST COLLECTION OF 12Z GFS/ECMWF/CANADIAN MODELS ALL SEEMED TO
HAVE MIGRATED TO THE OLD GFS SOLUTION. THE CONSENSUS NOW BRING FAIRLY
ROBUST LOW-LEVEL COLD ADVECTION THROUGH THE STATE SUNDAY NIGHT WITH
THE MID-LEVEL TROUGH/COLD POOL ONLY CLIPPING THE NRN EXTREMES OF
THE STATE. SOMEWHAT SURPRISED WITH THIS 12Z SOLUTION AS THE ECMWF
HAS MOVED TOWARDS THE GFS INSTEAD OF THE OTHER WAY AROUND. NOT
ENTIRELY READY TO SELL OUT ON THE NEW SOLUTION...SO WILL HEDGE
TOWARDS THE OLD ECMWF AND KEEP A FAIRLY ENERGETIC SYSTEM MOVING
THROUGH THE NRN THIRD OF THE STATE INTO EARLY MONDAY MORNING. HAVE
ADJUSTED THE DURATION/AMOUNTS OF SNOW...WHICH COULD KEEP NUMBERS
AT OR SLIGHTLY BELOW ADVISORY LEVELS SUNDAY NIGHT/EARLY MONDAY.
HIGH PRESSURE ALOFT WILL SETTLE ACROSS THE INTERIOR WEST FOR
MONDAY NIGHT THROUGH THURSDAY NIGHT. DRY CONDITIONS WITH A WARMING
TREND AT THE HIGHER ELEVATIONS THE GOING FORECAST MUCH OF THE
COMING WEEK. THE MEDIUM RANGE GUIDANCE DIFFER QUITE A BIT
FRIDAY/SATURDAY...WITH THE ECMWF BRINGING A RATHER SIGNIFICANT
SYSTEM THROUGH FRIDAY AND MUCH OF THE REMAINING GUIDANCE KEEPING
SOME FORM OF WEAK PROGRESSIVE FEATURE OVER NRN UTAH AND POINTS
NORTH. WITH THIS MUCH DIFFERENCE IN THE MODELS...WILL HEDGE
POPS/TEMPS TOWARDS CLIMATOLOGY WITH A SLIGHT BIAS TO THE ECMWF SIDE.
&&
.AVIATION...WINDS AT THE SLC TERMINAL WILL SHIFT TO THE
SOUTHEAST DRAINAGE BETWEEN 3Z AND 4Z. CEILINGS ARE EXPECTED TO
REMAIN ABOVE 7000 FEET THROUGH THE EVENING. VFR CONDITIONS WILL
PREVAIL.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&
$$
PUBLIC...CONGER
AVIATION...HOSENFELD
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
000
FXUS65 KSLC 211650
AFDSLC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
950 AM MST SAT NOV 21 2009
.SYNOPSIS...THE FIRST OF TWO UPPER LEVEL WEATHER DISTURBANCES WILL
CROSS NORTHERN UTAH TODAY. THE SECOND SYSTEM WILL PUSH A STRONGER
COLD FRONT ACROSS UTAH LATE SUNDAY THROUGH EARLY MONDAY. HIGH
PRESSURE ALOFT WILL SETTLE OVER UTAH EARLY NEXT WEEK...AND REMAIN
THE DOMINANT FEATURE THROUGH FRIDAY.
&&
.DISCUSSION...THE FIRST OF THE TWO EXPECTED UPPER LEVEL TROUGH TO
AFFECT UTAH WILL CROSS THE NRN HALF OF THE STATE TODAY...THEN EXIT
THE AREA EARLY THIS EVENING. A COUPLE OF DEFINABLE VORTICITY LOBES
CAN BE FOUND IN THE BASE OF THE TROUGH. THE FIRST MOVING ACROSS
NRN UTAH AT TIME PUSHED THE SURFACE FRONT THROUGH THE NORTH LAST
NIGHT. THIS FEATURE PRODUCED...AND IS STILL PRODUCING LIGHT SNOW
ACROSS THE FAR NRN ZONES THIS MORNING. THE SURFACE FRONT WILL
SETTLE INTO SRN UTAH THIS AFTERNOON AND REMAIN FAIRLY BENIGN AS
THE ASSOCIATED VORTICITY LOBE LIFTS E-NE INTO WY THIS AFTERNOON. A
SECOND VORTICITY LOBE MAY GENERATE ADDITIONAL LIGHT SNOW OVER THE
NRN/CNTRL ZONES AS THIS FEATURE DRAGS A LITTLE COOLER MID-LEVEL AIR
FURTHER SOUTH INTO THE STATE THIS AFTERNOON.
A SHORTWAVE RIDGE WILL DEVELOP TONIGHT AHEAD OF THE SECOND UPPER
TROUGH SCHEDULED TO ARRIVE FOR LATE SUNDAY THROUGH EARLY MONDAY.
THE VARIOUS MODEL GUIDANCE REMAIN CONSISTENT WITH THEIR RESPECTIVE
MODEL RUNS...WITH THE 00Z ECMWF STILL OFFERING THE BEST THREAT FOR
SUBSTANTIAL PRECIP SUNDAY NIGHT/MONDAY. FOR NOW WILL CONTINUE
ALONG WITH THE SOLUTION PUT FORTH BY THE BETTER PERFORMING ECMWF
AND KEEP THE HIGHER THREAT OF PRECIP GOING IN THE FORECAST.
MOUNTAIN SNOWS MAY BE SUFFICIENT FOR HIGHLIGHTS...THOUGH THESE
WOULD LIKELY BE ISSUED WITH TONIGHT FORECAST PACKAGE.
SOLID RIDGING BEGINNING EARLY IN THE COMING WEEK WILL MAINTAIN DRY
AND STABLE CONDITIONS STATEWIDE THROUGH AT LEAST EARLY FRIDAY.
THE HIGHER ELEVATIONS WILL SEE A WARMING TREND DURING THE WEEK...
WITH THE VALLEYS CLIMBING MORE SLOWLY BASED ON SNOW COVER AND
ELEVATION.
MAY ISSUED AN UPDATE FOR CLOUDS/PRECIP...THOUGH NO MAJOR CHANGES
ANTICIPATED AT THIS TIME.
&&
.AVIATION...WINDS AT THE SLC TERMINAL WILL REMAIN FROM THE NORTH
THROUGH THE DAY. CEILINGS ARE EXPECTED TO REMAIN AROUND 7000FT
THROUGH THE DAY...BUT MAY BRIEFLY DROP TO AROUND 6000FT. VFR
CONDITIONS WILL PREVAIL THROUGH THE TAF FORECAST PERIOD.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...NONE.
WY...NONE.
&&
$$
PUBLIC...CONGER
AVIATION...HOSENFELD
FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE)
| 
