[top]
000
FXUS65 KTWC 032200
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
300 PM MST FRI JUL 3 2009
.SYNOPSIS...THE COMBINATION OF SOLAR HEATING...A MOIST AIRMASS IN
PLACE ACROSS ALL OF SOUTHEAST ARIZONA...WEAK STORM MOTIONS AND A
LIFTING MECHANISM IN THE MIDDLE LEVELS OF THE ATMOSPHERE PUSHING
INTO THE AREA FROM THE SOUTH WILL RESULT IN NUMEROUS SHOWERS AND
THUNDERSTORMS WITH AN ENHANCED THREAT OF PRODUCING HEAVY RAINFALL
THIS AFTERNOON AND TONIGHT.
OTHERWISE...ABUNDANT MOISTURE WILL BRING SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS THIS HOLIDAY WEEKEND. AS A TROUGH PROGRESSES
INTO THE WEST COAST...DRIER AIR WILL MOVE INTO ARIZONA NEXT WEEK FOR A
DECREASE IN MOISTURE AND THUNDERSTORM ACTIVITY.
&&
.DISCUSSION...KEMX RADAR INDICATED MAINLY ISOLATED THUNDERSTORMS
OVER THE HIGHER TERRAIN OF SOUTHEAST ARIZONA EARLY THIS AFTERNOON...
WITH SCATTERED THUNDERSTORMS ACROSS SOUTH-CENTRAL ARIZONA. A LOOP OF
THE RADAR IMAGERY INDICATES THE WEAK MCV/MID-LEVEL FEATURE THAT WAS
OVER COCHISE COUNTY THIS MORNING IS NOW TRACKING WEST ACROSS SANTA
CRUZ COUNTY. I WOULD EXPECT THIS FEATURE WILL ENHANCE THUNDERSTORM
DEVELOPMENT AS IT TRACKS FURTHER WEST INTO THE LATE AFTERNOON HOURS.
THE 12Z KTWC UPPER AIR SOUNDING SHOWED A VERY MOIST AIRMASS RESIDING
ACROSS THE AREA...WITH A PRECIPITABLE WATER VALUE OF 1.56 INCHES.
THIS MOISTURE IS ALSO EVIDENT AT THE SURFACE...WITH SURFACE
DEWPOINTS IN THE UPPER 50S TO LOWER 60S. WEAK FLOW IS ALSO EVIDENT
ON THE UPPER AIR SOUNDING FROM THE SURFACE TO 500 MB. THIS WOULD
SUGGEST A WEAK MOTION TO STORMS TODAY ACROSS THE FORECAST AREA. THIS
FACT COMBINED WITH A VERY MOIST AIRMASS WOULD SUGGEST THAT THE MAIN
THREAT TODAY WILL BE VERY HEAVY RAIN...WITH A LOWER RISK FOR STRONG
THUNDERSTORM OUTFLOWS.
THE 500 MB HIGH CENTER IS OVER THE SOUTHERN PLAINS TODAY. WE SHOULD
CONTINUE TO SEE A MID-LEVEL DEFORMATION ZONE ROTATING NORTHWARD INTO
THE FAR SE CORNER OF THE STATE INTO THE EARLY EVENING. THIS FEATURE
WILL SERVE AS AS AN MECHANISM FOR THUNDERSTORM CONVECTION ACROSS THE
FORECAST AREA. GIVEN THE WEAK STORM MOTION...THE VERY MOIST
AIRMASS AND THIS FOCUSING MECHANISM ROTATING NORTHWARD ACROSS OUT
NECK OF THE WOODS...I CONSIDERED THE POSSIBILITY OF ISSUING A FLASH
FLOOD WATCH FOR PORTIONS OF MY FORECAST AREA. HOWEVER...I BELIEVE
THAT THE WEAK FEATURES MOVING ACROSS THE FORECAST AREA ARE NOT
SUFFICIENT ENOUGH TO ALLOW STORMS TO ORGANIZE INTO AND SIGNIFICANT
THUNDERSTORM CLUSTERS. GIVEN THIS...I DO NOT BELIEVE THAT THE HEAVY
RAIN WILL BE WIDESPREAD ENOUGH TO WARRANT THE WATCH.
THE 12Z NAM AND GFS MODELS TRY TO PICK UP A MID-LEVEL DISTURBANCE
CURRENTLY FIRING STORMS OVER EAST-CENTRAL SONORA MEXICO AND SHIFTS
IT INTO SOUTH CENTRAL AZ LATE THIS EVENING INTO THE OVERNIGHT
PERIOD. THIS FEATURE...IF IT INDEED MAKES ITS WAY UP INTO OUR NECK
OF THE WOODS COULD HELP ORGANIZE CONVECTION ACROSS THE WESTERN HALF
OF THE CWA AFTER MIDNIGHT AND HELP PRODUCE HEAVY RAINFALL. IN ANY
EVENT...I HAVE REFLECTED THIS THINKING IN THE 06Z-12Z DIGITAL
GRIDS.
OTHERWISE...THE UPPER TROUGH PUSHING INTO THE PACIFIC NORTHWEST
SQUASHES THE RIDGE...EVEN RESULTING IN A WEST/NORTHWEST FLOW INTO
SOUTHEAST ARIZONA LATE THIS WEEKEND INTO EARLY NEXT WEEK. ALTHOUGH
THIS WONT ENTIRELY REMOVE OUR MOISTURE...IT WILL REDUCE IT ENOUGH TO
LIMIT THE OVERALL COVERAGE OF STORMS ACROSS OUR FORECAST AREA.
&&
.AVIATION...THE COMBINATION OF SOLAR HEATING...A MOIST AIRMASS IN
PLACE ACROSS ALL OF SOUTHEAST ARIZONA...WEAK STORM MOTIONS AND A
LIFTING MECHANISM IN THE MIDDLE LEVELS OF THE ATMOSPHERE PUSHING
INTO THE AREA FROM THE SOUTH WILL RESULT IN NUMEROUS SHOWERS AND
THUNDERSTORMS WITH AN ENHANCED THREAT OF PRODUCING HEAVY RAINFALL
THIS AFTERNOON INTO TONIGHT. THESE STORMS WILL LOWER VISIBILITIES TO
1-3 NM IN HEAVY RAIN...WITH LOWER THAN NORMAL CLOUD CEILINGS.
ALTHOUGH THE RISK FOR STRONG AND GUSTY THUNDERSTORM WINDS TO 45 MPH
STILL EXISTS...THE OVERALL THREAT OF STRONG WINDS IS MINIMAL.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A MOIST ATMOSPHERE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SCATTERED THUNDERSTORMS THROUGH THE WEEKEND. A TROUGH
MOVING TOWARDS THE WEST COAST WILL SHIFT A DRIER WESTERLY FLOW INTO
ARIZONA NEXT WEEK...ALTHOUGH ENOUGH MOISTURE SHOULD REMAIN IN PLACE
TO MINIMIZE ANY FIRE WEATHER RISKS AND CONCERNS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
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000
FXUS65 KFGZ 032121
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 PM MST FRI JUL 3 2009
.SYNOPSIS...A MOIST AND UNSTABLE AIRMASS WILL REMAIN OVER NORTHERN
ARIZONA BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TODAY THROUGH
THE FOURTH OF JULY WEEKEND. A DRIER WESTERLY FLOW WILL DEVELOP BY
MONDAY WITH A DECREASE IN THE CHANCE OF SHOWERS. SEASONABLE
TEMPERATURES ARE EXPECTED THROUGH THE PERIOD.
&&
.DISCUSSION...A MOIST AND MODERATELY UNSTABLE AIRMASS REMAINS IN
PLACE ACROSS NRN AZ TODAY. KFGZ 12Z SOUNDING INDICATES STEEP LAPSE
RATES PRESENT BELOW ABOUT 550 MB...WITH MODERATE LAPSE RATES ABOVE.
PWAT IS DOWN A BIT FROM YESTERDAYS READINGS BUT STILL ABOUT 130
PERCENT OF NORMAL. FLOW BELOW 500 MB IS WEAK BUT SUBSTANTIAL ANVIL
LEVEL FLOW IS PRESENT. WITH THESE INGREDIENTS IN PLACE...
THUNDERSTORMS EARLY THIS AFTERNOON HAVE BEEN STRONGER THAN YESTERDAY
WITH SOME STORMS PRODUCING SMALL HAIL AND STRONG WINDS. IN
ADDITION...WEAK STEERING LEVEL FLOW HAS RESULTED IN SLOW MOVING
STORMS CAPABLE OF PRODUCING EXCESSIVE RAINFALL AMOUNTS.
THE SYNOPTIC PATTERN SHOULD PERSIST INTO SATURDAY AS HIGH PRESSURE
ALOFT REMAINS TO OUR EAST AND A SOUTHWEST TO WEST FLOW CONTINUES
ACROSS AZ. BY SUNDAY...A DRIER WESTERLY FLOW BEGINS TO MOVE ACROSS
NRN AZ WITH SOME DECREASE IN CHANCES FOR SHOWERS...MAINLY IN NWRN
AZ. ELSEWHERE...LITTLE CHANGE IS EXPECTED.
FOR MONDAY THROUGH WEDNESDAY...A DEEPENING WEST COAST TROUGH WILL
RESULT IN A DRIER SOUTHWESTERLY FLOW WITH DECREASING CHANCES OF
SHOWER ACTIVITY ACROSS ALL OF NRN AZ. LATE IN THE WEEK...HIGH
PRESSURE BEGINS TO REESTABLISH ITSELF ACROSS THE SOUTHWEST AND
MOISTURE WILL ONCE AGAIN INCREASE ACROSS AZ WITH BETTER CHANCES OF
SHOWERS AND THUNDERSTORMS.
&&
.AVIATION...FOR THE 00Z PACKAGE...SCT SHRA/TSRA ACTIVITY EXPECTED TO
LAST INTO THE EVENING HOURS. VFR CONDITIONS WILL BE THE CASE WITH
SCT MVFR CONDITIONS IN AND AROUND TS ACTIVITY. SOME OF THE HEAVIER
TS MAY RESULT IN LCL IFR CONDITIONS THROUGH THIS EVENING. STORMS ARE
FORECAST TO DIMINISH TO ISOLD AFT 04Z SATURDAY. ISOLD-SCT TS EXPTED
TO DVLP BY 18Z SATURDAY OVER THE HIGHER TERRAIN. VFR CONDITIONS
OVERALL WITH SCT MVFR CONDITIONS IN AND AROUND TS ACTIVITY LATE
MORNING AND AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR
AMENDMENTS.
&&
.FIRE WEATHER...HIGH PRESSURE WILL REMAIN TO OUR EAST THROUGH
SATURDAY. THE FLOW AROUND THE HIGH WILL PROVIDE MODERATE MOISTURE
WITH AFTERNOON MINIMUM RELATIVE HUMIDITY REMAINING ABOVE CRITICAL
VALUES. SCATTERED AFTERNOON AND EARLY EVENING SHOWERS AND
THUNDERSTORMS ARE EXPECTED BOTH SATURDAY AND SUNDAY...ALONG WITH
LOCALIZED GUSTY WINDS IN VICINITY OF THE STRONGER THUNDERSTORMS.
OUTSIDE OF THUNDERSTORM ACTIVITY...WINDS WILL BE LIGHT.
MONDAY THROUGH WEDNESDAY...THE SUBTROPICAL HIGH IS FORECAST TO SHIFT
TO THE WEST OF THE REGION MONDAY AND TUESDAY WITH A PACIFIC TROUGH
BRING MORE WESTERLY FLOW ACROSS THE REGION ON WEDNESDAY. AS A RESULT
LOOK FOR A SLOW DOWN TURN IN AFTERNOON THUNDERSTORM ACTIVITY WITH
PRECIPITATION CHANCES DROPPING TO AROUND 20 PERCENT ACROSS MOST OF
NORTHERN ARIZONA. MINIMUM AFTERNOON RH VALUES WILL RANGE FROM THE
MID TO UPPER 20S IN THE MOUNTAINS WITH AROUND 30 PERCENT ACROSS THE
WHITE MOUNTAINS...AND TEENS IN THE LOWER VALLEYS. WINDS WILL RUN
FROM 10 TO 15 MPH MONDAY...AND INCREASING TO 15 TO 20 MPH LATE
TUESDAY AND WEDNESDAY ACROSS THE KAIBAB AND COCONINO PLATEAUS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC..................DB
AVIATION/FIRE WEATHER...TC
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER
INFORMATION.
[top]
000
FXUS65 KPSR 031747 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1045 AM MST FRI JUL 3 2009
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
SUFFICIENT MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO THE
HOLIDAY WEEKEND...ALLOWING FOR AT LEAST A SLIGHT CHANCE OF MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE UPPER HIGH
PRESSURE SYSTEM RESPONSIBLE FOR FEEDING THIS MOISTURE INTO THE
REGION WILL SHIFT TO OUR WEST AND GIVE A DRIER FLOW PATTERN TO THE
AREA NEXT WEEK. THIS WILL PUSH THE SLIGHT CHANCE OF THUNDERSTORMS
BACK GENERALLY TO THE EAST OF THE GREATER PHOENIX AREA. MEANWHILE
...TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...
STRONG VORT MAX DID IN FACT DEVELOP OVERNIGHT ACROSS NORTHERN
SONORA/SE AZ...BUT FAILED TO PRODUCE PRECIPITATION ACROSS THE
FORECAST AREA. DEBRIS CLOUDINESS WITH THIS CIRCULATION HAS BEEN
CONFINED TO EASTERN AZ THIS MORNING. FULL SUNSHINE ACROSS MUCH OF
THE CWA MAKES TODAYS FORECAST MORE OF TEXTBOOK CASE. CLOUDS ARE
ALREADY FORMING ALONG THE MOGOLLON RIM AND ACROSS THE PEAKS OF NW
AZ. STEERING FLOW WILL CONTINUE TO VEER...SUGGESTING THAT ISOLATED
ACTIVITY ALONG THE RIM WILL SLOWLY WORK ITS WAY INTO THE LOWER
ELEVATIONS LATE THIS AFTERNOON AND THIS EVENING.
MODELS HAVE INITIALIZED WELL THIS MORNING AND INDICATE SUFFICIENT
CAPE FOR ISOLATED THUNDERSTORMS IN THE PHOENIX METRO AREA LATER
TODAY. EARLY 12Z ACARS SOUNDING SHOWED A LITTLE BIT OF A CAP AROUND
500 MB...THOUGH THAT HAS DIMINISHED AS OF 15Z. FLOW GENERALLY
REMAINS DIVERGENT ALOFT...THOUGH WITHOUT MUCH OF A DYNAMIC
TRIGGER...IT WILL TAKE INTENSE HEATING OR AN OUTFLOW BOUNDARY TO
REALIZE THE INSTABILITY.
NO SIGNIFICANT CHANGES TO THE FORECAST ARE ANTICIPATED THIS MORNING.
PREVIOUS DISCUSSION...
SYNOPTICALLY...WE ARE LOOKING AT THE UPPER LEVEL RIDGE CENTERED OFF
TO OUR E...WITH A WEAKENING TROUGH OVER THE CA COAST. THESE TWO
FEATURES ARE KEEPING A MOIST...S/SELY FLOW IN PLACE ACROSS THE CWA
EARLY TODAY. SATELLITE-ESTIMATED PWATERS ARE STILL AROUND 1.5 INCHES
OVER SCNTRL DESERTS...LESSER AMOUNTS OUT IN WRN CWA. HARD TO SEE ANY
APPRECIABLE FEATURES ON WV THAT COULD POTENTIALLY SERVE TO ENHANCE
CONVECTION TODAY...AND WITH STEERING FLOWS REMAINING OUT OF THE S
AND SW...CONDS STILL NOT ALL THAT FAVORABLE FOR ACTIVITY COMING OFF
THE RIM AND INTERACTING WITH ANY POTENTIAL BOUNDARIES FROM THE S.
STILL...WE SHOULD HAVE LOTS OF INSOLATION TO WORK WITH TODAY TO HELP
US REALIZE SOME CAPE...SO A DECENT BATCH OF TSTMS SHOULD GET GOING
MAINLY OVER THE HIGHER TERRAIN AND THEN DRIFT TOWARDS THE DESERTS.
THEREFORE...WILL OPT TO KEEP POPS IN THE LOW-GRADE MONSOON LEVELS...
IE 10-20 PCNT MOST AREAS E OF THE CO RIVER...WITH HIGHER POPS IN THE
USUALLY CONVECTIVELY ACTIVE MOUNTAINOUS REGIONS TO THE E OF THE
GREATER PHX AREA.
THE AFOREMENTIONED UPPER RIDGE WILL RETROGRADE TO OUR W PER SHORT-
RANGE MODEL GUIDANCE. THIS WILL PUT THE CWA IN A MORE W/NWLY FLOW
OVER THE HOLIDAY WEEKEND. THIS WILL CERTAINLY NOT PORTEND TO ANY
MAJOR MOISTURE INCREASE TO BE SURE...IN FACT WE MAY SEE SOME GRADUAL
DRYING TAKE PLACE WITH THIS PATTERN. WILL LEAVE SLIGHT CHANCES GOING
RIGHT ON THRU THE WEEKEND E OF LOWER CO RIVER VALLEY.
NEXT WEEK...BOTH ECMWF AND GFS ARE CONTINUING TO FORECAST ANOTHER
MAJOR TROUGH TO MOVE OVER THE W COAST. THIS WILL PLACE ALL BUT SE AZ
IN A MUCH DRIER FLOW PATTERN...WHEREBY AT MIDWEEK...WE MAY SEE THE
MOISTURE PUSHED BACK TO JUST SRN GILA COUNTY...OR MAYBE EVEN FURTHER
E. FOR NOW...WILL NOT CALL FOR A TOTAL SCOURING OUT OF MOISTURE
(HARD TO DO THIS TIME OF THE MONSOON)...OPTING TO LEAVE A SLIGHT
CHANCE GOING IN ZONE 24 RIGHT ON THRU THE EXTENDED. IF WE DRY
OUT...OF COURSE WE WILL HAVE A BETTER POTENTIAL OF GETTING HOTTER
AGAIN NEXT WEEK. FOR NOW...WILL KEEP MAX TEMPS FAIRLY CLOSE TO EARLY
JULY NORMS.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
CU AND TCU BUILDING OVER MOUNTAINS AT 17Z PER 88D AND PIREPS...IN
RATHER MOIST ENVIRONMENT. IN FACT...YOUR LATEST PHOENIX SOUNDING HAD
1.69 INCHES OF P/WATER WITH A WEAK STABLE LAYER AT 20 THSD FEET.
CONVECTION IS UNDERWAY...AND STEERING FLOW REMAINS IDEAL FOR ISOLD
ACTIVITY TO DRIFT INTO THE AREA AFTER 00Z. OUTFLOW WINDS COULD
BE STRONG ENUF TO KICK UP DUST BUT STILL NOT CONFIDENT TOO SHOW THAT
HAZARD IN 18Z TAFS. FOR THE 4TH...WITH A POSSIBLE INCREASE IN
MOISTURE WE COULD SEE MORE CLOUDS BTWN 9 AND 12 THD FT.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
DRIER MID-LEVEL AIR WORKING INTO THE REGION TODAY. COUPLED WITH A
CAP LIKELY WON/T SEE MUCH CONVECTIVE ACTIVITY...LIKELY ONLY AROUND
THE MTNS NEAR KBLH. GENERALLY LIGHT WINDS UNTIL LATE TOIGHT WHEN
SOUTHERLY WINDS KICK UP AND A GULF SURGE ARRIVES FOR YOUR 4TH.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TROUGH MOVING TOWARD THE WEST COAST BY SUNDAY WILL SLOWLY SPREAD DRY
OVER THE FORECAST AREA BY TUESDAY. PRECIP CHANCES ACCORDINGLY
DECREASE. TEMPERATURES WILL ALSO INCH UP MEANING RH LEVELS WILL
DROP. SOUTHWEST WINDS COULD BE GUSTY AT TIMES DURING THE AFTERNOON
HOURS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/ESTLE
AVIATION...SIPPLE
FIRE WEATHER...INIGUEZ
000
FXUS65 KFGZ 031627
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
930 AM MST FRI JUL 3 2009
.SYNOPSIS...A MOIST AND UNSTABLE AIRMASS WILL REMAIN OVER NORTHERN
ARIZONA BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TODAY THROUGH
THE FOURTH OF JULY WEEKEND. A DRIER WESTERLY FLOW WILL DEVELOP BY
MONDAY WITH A DECREASE IN THE CHANCE OF SHOWERS. SEASONABLE
TEMPERATURES ARE EXPECTED THROUGH THE PERIOD.
&&
.DISCUSSION...A MOIST AND MODERATELY UNSTABLE AIRMASS REMAINS IN
PLACE ACROSS NRN AZ TODAY. MORNING SOUNDING INDICATES STEEP LAPSE
RATES PRESENT BELOW ABOUT 550 MB...WITH MODERATE LAPSE RATES ABOVE.
PWAT IS DOWN A BIT FROM YESTERDAYS READINGS BUT STILL ABOUT 130
PERCENT OF NORMAL. FLOW BELOW 500 MB IS WEAK BUT SUBSTANTIAL UPPER
LEVEL AND ANVIL LEVEL FLOW IS PRESENT. WITH THESE INGREDIENTS IN
PLACE...EXPECT THAT THUNDERSTORMS TODAY WILL BE A BIT STRONGER THAN
YESTERDAY WITH SOME STORMS PRODUCING SMALL HAIL AND STRONG WINDS. IN
ADDITION...WEAK STEERING LEVEL FLOW WILL RESULT IN SLOW MOVING STORMS
CAPABLE OF PRODUCING EXCESSIVE RAINFALL AMOUNTS. WINDS AT ALL LEVELS
WERE FROM THE WEST SO EXPECT STORMS FORMING OVER THE HIGHER TERRAIN
LATE THIS MORNING AND EARLY AFTERNOON TO MOVE EASTWARD INTO LOWER
ELEVATIONS BY LATE AFTERNOON. THIS SHOULD RESULT IN BETTER CHANCES OF
PCPN ACROSS THE LCR COMPARED TO THE PAST FEW DAYS.
THIS PATTERN SHOULD PERSIST INTO SATURDAY AS HIGH PRESSURE ALOFT
REMAINS TO OUR EAST AND A SOUTHWEST TO WEST FLOW CONTINUES ACROSS
AZ. BY SUNDAY...A DRIER WESTERLY FLOW BEGINS TO MOVE ACROSS NRN AZ
WITH SOME DECREASE IN CHANCES FOR SHOWERS IN NWRN AZ. ELSEWHERE...
LITTLE CHANGE IS EXPECTED.
FOR MONDAY THROUGH WEDNESDAY...A DEEPENING WEST COAST TROUGH WILL
RESULT IN A DRIER SOUTHWESTERLY FLOW WITH DECREASING CHANCES OF
SHOWER ACROSS ALL OF NRN AZ. LATE IN THE WEEK...HIGH PRESSURE BEGINS
TO REESTABLISH ITSELF ACROSS THE SOUTHWEST AND MOISTURE WILL ONCE
AGAIN INCREASE ACROSS AZ WITH BETTER CHANCES OF SHOWERS AND
THUNDERSTORMS.
&&
.AVIATION...FOR THE 18Z PACKAGE...SCT SHRA/TSRA WILL DVLP ONCE AGAIN
AND LAST INTO THE EVENING HOURS WITH MOST STORMS MOVING IN AN
EASTERLY DIRECTION...EXCEPT SOUTH OF THE RIM STORM MOVEMENT IS
EXPECTED TO BE IN A SLOW SOUTHERLY DIRECTION. VFR CONDITIONS WILL BE
THE CASE WITH SCT MVFR CONDITIONS IN AND AROUND TS ACTIVITY. SOME OF
THE HEAVIER TS MAY RESULT IN BRIEF IFR CONDITIONS DURING THE
AFTERNOON AND EARLY EVENING. STORMS ARE FORECAST TO DIMINISH TO
ISOLD AFT 04Z SATURDAY. AVIATION DISCUSSION NOT UPDATED FOR
AMENDMENTS.
&&
.FIRE WEATHER...HIGH PRESSURE WILL REMAIN CENTERED TO OUR EAST
THROUGH SATURDAY. THE FLOW AROUND THE HIGH WILL PROVIDE MODERATE
MOISTURE WITH AFTERNOON MINIMUM RELATIVE HUMIDITY REMAINING ABOVE
CRITICAL VALUES. SCATTERED AFTERNOON AND EARLY EVENING SHOWERS AND
THUNDERSTORMS ARE EXPECTED BOTH TODAY AND SATURDAY...ALONG WITH
LOCALIZED GUSTY WINDS IN VICINITY OF THE STRONGER THUNDERSTORMS.
OUTSIDE OF THUNDERSTORM ACTIVITY...WINDS WILL BE LIGHT.
SUNDAY THROUGH TUESDAY...A DRYING TREND IS EXPECTED THROUGH THE
PERIOD AS DEEPER WESTERLY FLOW RESUMES. THE CHANCE FOR AFTERNOON AND
EVENING SHOWER AND THUNDERSTORM ACTIVITY WILL BE LESS THAN 20
PERCENT ACROSS MOST OF NORTHERN ARIZONA...EXCEPT 20-25 PERCENT ALONG
THE MOGOLLON RIM. MINIMUM AFTERNOON RH VALUES WILL RANGE FROM 30-35
PERCENT ACROSS THE WHITE MOUNTAINS TO 10-15 PERCENT ACROSS THE GRAND
CANYON COUNTRY AND KAIBAB PLATEAU. WINDS WILL REMAIN BELOW 15 MPH
THROUGH PERIOD...EXCEPT INCREASING TO NEAR 20 MPH LATE MONDAY AND
TUESDAY ACROSS THE KAIBAB AND COCONINO PLATEAUS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC..................DB
AVIATION/FIRE WEATHER...TC
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER
INFORMATION.
000
FXUS65 KPSR 031627
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
930 AM MST FRI JUL 3 2009
.SYNOPSIS...
SUFFICIENT MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO THE
HOLIDAY WEEKEND...ALLOWING FOR AT LEAST A SLIGHT CHANCE OF MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE UPPER HIGH
PRESSURE SYSTEM RESPONSIBLE FOR FEEDING THIS MOISTURE INTO THE
REGION WILL SHIFT TO OUR WEST AND GIVE A DRIER FLOW PATTERN TO THE
AREA NEXT WEEK. THIS WILL PUSH THE SLIGHT CHANCE OF THUNDERSTORMS
BACK GENERALLY TO THE EAST OF THE GREATER PHOENIX AREA. MEANWHILE
...TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...
STRONG VORT MAX DID IN FACT DEVELOP OVERNIGHT ACROSS NORTHERN
SONORA/SE AZ...BUT FAILED TO PRODUCE PRECIPITATION ACROSS THE FORECAST
AREA. DEBRIS CLOUDINESS WITH THIS CIRCULATION HAS BEEN CONFINED TO
EASTERN AZ THIS MORNING. FULL SUNSHINE ACROSS MUCH OF THE CWA MAKES
TODAYS FORECAST MORE OF TEXTBOOK CASE. CLOUDS ARE ALREADY FORMING
ALONG THE MOGOLLON RIM AND ACROSS THE PEAKS OF NW AZ. STEERING FLOW
WILL CONTINUE TO VEER...SUGGESTING THAT ISOLATED ACTIVITY ALONG THE
RIM WILL SLOWLY WORK ITS WAY INTO THE LOWER ELEVATIONS LATE THIS
AFTERNOON AND THIS EVENING.
MODELS HAVE INITIALIZED WELL THIS MORNING AND INDICATE SUFFICIENT
CAPE FOR ISOLATED THUNDERSTORMS IN THE PHOENIX METRO AREA LATER
TODAY. EARLY 12Z ACARS SOUNDING SHOWED A LITTLE BIT OF A CAP AROUND
500 MB...THOUGH THAT HAS DIMINISHED AS OF 15Z. FLOW GENERALLY REMAINS
DIVERGENT ALOFT...THOUGH WITHOUT MUCH OF A DYNAMIC TRIGGER...IT WILL
TAKE INTENSE HEATING OR AN OUTFLOW BOUNDARY TO REALIZE THE
INSTABILITY.
NO SIGNIFICANT CHANGES TO THE FORECAST ARE ANTICIPATED THIS MORNING.
PREVIOUS DISCUSSION...
SYNOPTICALLY...WE ARE LOOKING AT THE UPPER LEVEL RIDGE CENTERED OFF
TO OUR E...WITH A WEAKENING TROUGH OVER THE CA COAST. THESE TWO
FEATURES ARE KEEPING A MOIST...S/SELY FLOW IN PLACE ACROSS THE CWA
EARLY TODAY. SATELLITE-ESTIMATED PWATERS ARE STILL AROUND 1.5 INCHES
OVER SCNTRL DESERTS...LESSER AMOUNTS OUT IN WRN CWA. HARD TO SEE ANY
APPRECIABLE FEATURES ON WV THAT COULD POTENTIALLY SERVE TO ENHANCE
CONVECTION TODAY...AND WITH STEERING FLOWS REMAINING OUT OF THE S
AND SW...CONDS STILL NOT ALL THAT FAVORABLE FOR ACTIVITY COMING OFF
THE RIM AND INTERACTING WITH ANY POTENTIAL BOUNDARIES FROM THE S.
STILL...WE SHOULD HAVE LOTS OF INSOLATION TO WORK WITH TODAY TO HELP
US REALIZE SOME CAPE...SO A DECENT BATCH OF TSTMS SHOULD GET GOING
MAINLY OVER THE HIGHER TERRAIN AND THEN DRIFT TOWARDS THE DESERTS.
THEREFORE...WILL OPT TO KEEP POPS IN THE LOW-GRADE MONSOON LEVELS...
IE 10-20 PCNT MOST AREAS E OF THE CO RIVER...WITH HIGHER POPS IN THE
USUALLY CONVECTIVELY ACTIVE MOUNTAINOUS REGIONS TO THE E OF THE
GREATER PHX AREA.
THE AFOREMENTIONED UPPER RIDGE WILL RETROGRADE TO OUR W PER SHORT-
RANGE MODEL GUIDANCE. THIS WILL PUT THE CWA IN A MORE W/NWLY FLOW
OVER THE HOLIDAY WEEKEND. THIS WILL CERTAINLY NOT PORTEND TO ANY
MAJOR MOISTURE INCREASE TO BE SURE...IN FACT WE MAY SEE SOME GRADUAL
DRYING TAKE PLACE WITH THIS PATTERN. WILL LEAVE SLIGHT CHANCES GOING
RIGHT ON THRU THE WEEKEND E OF LOWER CO RIVER VALLEY.
NEXT WEEK...BOTH ECMWF AND GFS ARE CONTINUING TO FORECAST ANOTHER
MAJOR TROUGH TO MOVE OVER THE W COAST. THIS WILL PLACE ALL BUT SE AZ
IN A MUCH DRIER FLOW PATTERN...WHEREBY AT MIDWEEK...WE MAY SEE THE
MOISTURE PUSHED BACK TO JUST SRN GILA COUNTY...OR MAYBE EVEN FURTHER
E. FOR NOW...WILL NOT CALL FOR A TOTAL SCOURING OUT OF MOISTURE
(HARD TO DO THIS TIME OF THE MONSOON)...OPTING TO LEAVE A SLIGHT
CHANCE GOING IN ZONE 24 RIGHT ON THRU THE EXTENDED. IF WE DRY
OUT...OF COURSE WE WILL HAVE A BETTER POTENTIAL OF GETTING HOTTER
AGAIN NEXT WEEK. FOR NOW...WILL KEEP MAX TEMPS FAIRLY CLOSE TO EARLY
JULY NORMS.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
EASTERLY FLOW TO CONTINUE INTO THIS EARLY AFTERNOON BEFORE SLOWLY
TURNING TO THE SW...ALBEIT WEAKLY. DATA FROM THIS MORNING/S BALLOON
LAUNCH SHOWS INSTABILITY HAS INCREASED FROM YESTERDAY YET A
WEAKENING CAP REMAINS. NO CLEAR TRIGGERING MECHANISMS EXPECTED FOR
THIS AFTERNOON SO CONVECTION MAY END UP BEING SPOTTY AND MORE AROUND
PHX THAN OVER IT. HAVE INCLUDED CBS AS WE/LL LIKELY SEE STORMS
WITHIN 50 NM OF THE AIRPORTS. LESS CLOUDS THIS MORNING THOUGH COULD
MEAN AN EARLIER START TO STORMS IN THE AREA...WE/LL WATCH HOW THINGS
DEVELOP THROUGH THE MORNING.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
DRIER MID-LEVEL AIR WORKING INTO THE REGION TODAY. COUPLED WITH A
CAP LIKELY WON/T SEE MUCH CONVECTIVE ACTIVITY...LIKELY ONLY AROUND
THE MTNS NEAR KBLH. GENERALLY LIGHT WINDS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TROUGH MOVING TOWARD THE WEST COAST BY SUNDAY WILL SLOWLY SPREAD DRY
OVER THE FORECAST AREA BY TUESDAY. PRECIP CHANCES ACCORDINGLY
DECREASE. TEMPERATURES WILL ALSO INCH UP MEANING RH LEVELS WILL
DROP. SOUTHWEST WINDS COULD BE GUSTY AT TIMES DURING THE AFTERNOON
HOURS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/ESTLE
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ
000
FXUS65 KTWC 031621
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
920 AM MST FRI JUL 3 2009
.SYNOPSIS...THE COMBINATION OF SOLAR HEATING...A MOIST AIRMASS IN
PLACE ACROSS ALL OF SOUTHEAST ARIZONA...WEAK STORM MOTIONS AND A
LIFTING MECHANISM IN THE MIDDLE LEVELS OF THE ATMOSPHERE PUSHING
INTO THE AREA FROM THE SOUTH WILL RESULT IN AFTERNOON SHOWERS AND
THUNDERSTORMS WITH AN ENHANCED THREAT OF PRODUCING HEAVY RAINFALL.
OTHERWISE...ABUNDANT MOISTURE WILL BRING SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS THIS HOLIDAY WEEKEND. AS A TROUGH PROGRESSES
INTO THE WEST COAST...DRIER AIR WILL MOVE INTO ARIZONA NEXT WEEK FOR A
DECREASE IN MOISTURE AND THUNDERSTORM ACTIVITY.
&&
.DISCUSSION...THE LATEST SATELLITE AND RADAR IMAGERY ACROSS THE
DESERT SOUTHWEST DEPICTS TWO DECAYING THUNDERSTORM COMPLEXES...ONE
IN EASTERN SONORA MEXICO AND ANOTHER IN CENTRAL NEW MEXICO. CLOUD
COVER ACROSS THE EASTERN PORTIONS OF THE FORECAST AREA DUE TO THE
REMNANTS OF THE THUNDERSTORM COMPLEX OVER SONORA. A WEAK MCV OR
MESOSCALE CONVECTIVE VORTEX CAN BE SEEN ON A LOOP OF THE VISIBLE
SATELLITE OVER NORTHEAST SONORA. ALTHOUGH THIS FEATURE IS WEAK...IT
IS WILL REMAIN JUST STRONG ENOUGH TO ADVECT SIGNIFICANT CLOUD COVER
WITH LIGHT SHOWERS NORTHWARD INTO COCHISE COUNTY THROUGH THE LATE
MORNING.
OTHERWISE...THE 12Z KTWC UPPER AIR SOUNDING SHOWING A VERY MOIST
AIRMASS RESIDING ACROSS THE AREA...WITH A PRECIPITABLE WATER VALUE
OF 1.56 INCHES. THIS MOISTURE IS ALSO EVIDENT AT THE SURFACE...WITH
THE 9 AM MST SURFACE DEWPOINTS IN THE LOW TO MID 60S. WEAK FLOW ALSO
EVIDENT ON THE UPPER AIR SOUNDING FROM THE SURFACE TO 500 MB. THIS
WOULD SUGGEST A WEAK MOTION TO STORMS TODAY ACROSS THE FORECAST
AREA. THIS FACT COMBINED WITH A VERY MOIST AIRMASS WOULD SUGGEST
THAT THE MAIN THREAT TODAY WILL BE VERY HEAVY RAIN...WITH A LOWER
RISK FOR STRONG THUNDERSTORM OUTFLOWS.
WITH THE 500 MB HIGH CENTER OVER THE SOUTHERN PLAINS THIS MORNING...
WE SHOULD SEE A MID-LEVEL DEFORMATION ZONE ROTATING NORTHWARD INTO
THE FAR SE CORNER OF THE STATE. THIS FEATURE WILL SERVE AS AS AN
MECHANISM FOR THUNDERSTORM CONVECTION ACROSS THE FORECAST AREA
TODAY. GIVEN THE WEAK STORM MOTION...THE VERY MOIST AIRMASS AND THIS
FOCUSING MECHANISM ROTATING NORTHWARD ACROSS OUT NECK OF THE
WOODS...I AM CONSIDERING THE POSSIBILITY OF ISSUING A FLASH FLOOD
WATCH ACROSS THE EASTERN PORTIONS OF MY FORECAST AREA TODAY. MY
MAJOR CONCERN RIGHT NOW IS THE CLOUD COVER ACROSS THE EASTERN
COUNTIES. THE CLOUD COVER/MCV ROTATING NORTH INTO THE AREA WILL KEEP
THE SOLAR HEATING DOWN THROUGH THE MORNING HOURS...BUT SHOULD BEGIN
TO CLEAR OUT AROUND NOON. IT IS ENTIRELY POSSIBLE THAT THE HEAVIEST
RAINFALL COULD BE ALONG THE PERIPHERY OF THIS CLOUD COVER WHERE THE
BETTER SURFACE HEATING WILL OCCUR...ESPECIALLY GIVEN THAT THIS
DEFORMATION ZONE WILL PUSH THROUGH THIS AREA AS WELL.
IN ANY EVENT...IT LOOKS LIKE THE POTENTIAL FOR HEAVY RAIN EXISTS
TODAY AND I WILL MAKE AN UPDATE TO THE FORECAST IN INCLUDE HEAVY
RAIN WORDING.
&&
.AVIATION...SIGNIFICANT MAINLY MID LEVEL CLOUD COVER ACROSS
COCHISE...GRAHAM AND GREENLEE COUNTIES THIS MORNING DUE TO THE
REMNANTS OF A THUNDERSTORM COMPLEX OVER SONORA MEXICO. A WEAK
DISTURBANCE PUSHING INTO THIS AREA THIS MORNING WILL RESULT IN A
CHANCE OF LIGHT SHOWERS THROUGH THE LATE MORNING HOURS.
OTHERWISE...THE COMBINATION OF SOLAR HEATING...A MOIST AIRMASS IN
PLACE ACROSS ALL OF SOUTHEAST ARIZONA...WEAK STORM MOTIONS AND A
LIFTING MECHANISM IN THE MIDDLE LEVELS OF THE ATMOSPHERE PUSHING
INTO THE AREA FROM THE SOUTH WILL RESULT IN AFTERNOON SHOWERS AND
THUNDERSTORMS WITH AN ENHANCED THREAT OF PRODUCING HEAVY RAINFALL.
THESE STORMS CAN LOWER VISIBILITIES TO 3-5 NM IN HEAVY RAIN...WITH
LOWER THAN NORMAL CLOUD CEILINGS. ALTHOUGH THE RISK FOR STRONG AND
GUSTY THUNDERSTORM WINDS TO 45 MPH STILL EXISTS TODAY...THE OVERALL
THREAT OF STRONG WINDS IS MINIMAL TODAY. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A MOIST ATMOSPHERE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SCATTERED THUNDERSTORMS THROUGH THE WEEKEND. A TROUGH
MOVING TOWARDS THE WEST COAST WILL SHIFT A DRIER WESTERLY FLOW INTO
ARIZONA NEXT WEEK...ALTHOUGH ENOUGH MOISTURE SHOULD REMAIN IN PLACE
TO MINIMIZE ANY FIRE WEATHER RISKS AND CONCERNS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KPSR 031256 AAA
AFDPSR
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PHOENIX AZ
555 AM MST FRI JUL 3 2009
.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
&&
.SYNOPSIS...
SUFFICIENT MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO THE
HOLIDAY WEEKEND...ALLOWING FOR AT LEAST A SLIGHT CHANCE OF MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE UPPER HIGH
PRESSURE SYSTEM RESPONSIBLE FOR FEEDING THIS MOISTURE INTO THE
REGION WILL SHIFT TO OUR WEST AND GIVE A DRIER FLOW PATTERN TO THE
AREA NEXT WEEK. THIS WILL PUSH THE SLIGHT CHANCE OF THUNDERSTORMS
BACK GENERALLY TO THE EAST OF THE GREATER PHOENIX AREA. MEANWHILE
...TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...
EVENING CONVECTION LAST NIGHT WENT TO BED PRETTY QUICKLY...AND EARLY
MORNING SATELLITE PIX SHOW GENERALLY CLEAR SKIES ACROSS MOST OF THE
PHX CWA. ONLY EXCEPTION TO THIS WAS OVER THE FAR ERN CWA...WHERE A
LARGE SWWD PROPAGATING MCS DOWN OVER SONORA MEXICO WAS THROWING SOME
MID/HIGH LEVEL MOISTURE UP THAT WAY.
SYNOPTICALLY...WE ARE LOOKING AT THE UPPER LEVEL RIDGE CENTERED OFF
TO OUR E...WITH A WEAKENING TROUGH OVER THE CA COAST. THESE TWO
FEATURES ARE KEEPING A MOIST...S/SELY FLOW IN PLACE ACROSS THE CWA
EARLY TODAY. SATELLITE-ESTIMATED PWATERS ARE STILL AROUND 1.5 INCHES
OVER SCNTRL DESERTS...LESSER AMOUNTS OUT IN WRN CWA. HARD TO SEE ANY
APPRECIABLE FEATURES ON WV THAT COULD POTENTIALLY SERVE TO ENHANCE
CONVECTION TODAY...AND WITH STEERING FLOWS REMAINING OUT OF THE S
AND SW...CONDS STILL NOT ALL THAT FAVORABLE FOR ACTIVITY COMING OFF
THE RIM AND INTERACTING WITH ANY POTENTIAL BOUNDARIES FROM THE S.
STILL...WE SHOULD HAVE LOTS OF INSOLATION TO WORK WITH TODAY TO HELP
US REALIZE SOME CAPE...SO A DECENT BATCH OF TSTMS SHOULD GET GOING
MAINLY OVER THE HIGHER TERRAIN AND THEN DRIFT TOWARDS THE DESERTS.
THEREFORE...WILL OPT TO KEEP POPS IN THE LOW-GRADE MONSOON LEVELS...
IE 10-20 PCNT MOST AREAS E OF THE CO RIVER...WITH HIGHER POPS IN THE
USUALLY CONVECTIVELY ACTIVE MOUNTAINOUS REGIONS TO THE E OF THE
GREATER PHX AREA.
THE AFOREMENTIONED UPPER RIDGE WILL RETROGRADE TO OUR W PER SHORT-
RANGE MODEL GUIDANCE. THIS WILL PUT THE CWA IN A MORE W/NWLY FLOW
OVER THE HOLIDAY WEEKEND. THIS WILL CERTAINLY NOT PORTEND TO ANY
MAJOR MOISTURE INCREASE TO BE SURE...IN FACT WE MAY SEE SOME GRADUAL
DRYING TAKE PLACE WITH THIS PATTERN. WILL LEAVE SLIGHT CHANCES GOING
RIGHT ON THRU THE WEEKEND E OF LOWER CO RIVER VALLEY.
NEXT WEEK...BOTH ECMWF AND GFS ARE CONTINUING TO FORECAST ANOTHER
MAJOR TROUGH TO MOVE OVER THE W COAST. THIS WILL PLACE ALL BUT SE AZ
IN A MUCH DRIER FLOW PATTERN...WHEREBY AT MIDWEEK...WE MAY SEE THE
MOISTURE PUSHED BACK TO JUST SRN GILA COUNTY...OR MAYBE EVEN FURTHER
E. FOR NOW...WILL NOT CALL FOR A TOTAL SCOURING OUT OF MOISTURE
(HARD TO DO THIS TIME OF THE MONSOON)...OPTING TO LEAVE A SLIGHT
CHANCE GOING IN ZONE 24 RIGHT ON THRU THE EXTENDED. IF WE DRY
OUT...OF COURSE WE WILL HAVE A BETTER POTENTIAL OF GETTING HOTTER
AGAIN NEXT WEEK. FOR NOW...WILL KEEP MAX TEMPS FAIRLY CLOSE TO EARLY
JULY NORMS.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
EASTERLY FLOW TO CONTINUE INTO THIS EARLY AFTERNOON BEFORE SLOWLY
TURNING TO THE SW...ALBEIT WEAKLY. DATA FROM THIS MORNING/S BALLOON
LAUNCH SHOWS INSTABILITY HAS INCREASED FROM YESTERDAY YET A
WEAKENING CAP REMAINS. NO CLEAR TRIGGERING MECHANISMS EXPECTED FOR
THIS AFTERNOON SO CONVECTION MAY END UP BEING SPOTTY AND MORE AROUND
PHX THAN OVER IT. HAVE INCLUDED CBS AS WE/LL LIKELY SEE STORMS
WITHIN 50 NM OF THE AIRPORTS. LESS CLOUDS THIS MORNING THOUGH COULD
MEAN AN EARLIER START TO STORMS IN THE AREA...WE/LL WATCH HOW THINGS
DEVELOP THROUGH THE MORNING.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
DRIER MID-LEVEL AIR WORKING INTO THE REGION TODAY. COUPLED WITH A
CAP LIKELY WON/T SEE MUCH CONVECTIVE ACTIVITY...LIKELY ONLY AROUND
THE MTNS NEAR KBLH. GENERALLY LIGHT WINDS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TROUGH MOVING TOWARD THE WEST COAST BY SUNDAY WILL SLOWLY SPREAD DRY
OVER THE FORECAST AREA BY TUESDAY. PRECIP CHANCES ACCORDINGLY
DECREASE. TEMPERATURES WILL ALSO INCH UP MEANING RH LEVELS WILL
DROP. SOUTHWEST WINDS COULD BE GUSTY AT TIMES DURING THE AFTERNOON
HOURS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...ESTLE
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ
000
FXUS65 KPSR 031055
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
355 AM MST FRI JUL 3 2009
.SYNOPSIS...
SUFFICIENT MOISTURE WILL REMAIN IN PLACE ACROSS THE AREA INTO THE
HOLIDAY WEEKEND...ALLOWING FOR AT LEAST A SLIGHT CHANCE OF MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE UPPER HIGH
PRESSURE SYSTEM RESPONSIBLE FOR FEEDING THIS MOISTURE INTO THE
REGION WILL SHIFT TO OUR WEST AND GIVE A DRIER FLOW PATTERN TO THE
AREA NEXT WEEK. THIS WILL PUSH THE SLIGHT CHANCE OF THUNDERSTORMS
BACK GENERALLY TO THE EAST OF THE GREATER PHOENIX AREA. MEANWHILE
...TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE SEASONAL NORMALS.
&&
.DISCUSSION...
EVENING CONVECTION LAST NIGHT WENT TO BED PRETTY QUICKLY...AND EARLY
MORNING SATELLITE PIX SHOW GENERALLY CLEAR SKIES ACROSS MOST OF THE
PHX CWA. ONLY EXCEPTION TO THIS WAS OVER THE FAR ERN CWA...WHERE A
LARGE SWWD PROPAGATING MCS DOWN OVER SONORA MEXICO WAS THROWING SOME
MID/HIGH LEVEL MOISTURE UP THAT WAY.
SYNOPTICALLY...WE ARE LOOKING AT THE UPPER LEVEL RIDGE CENTERED OFF
TO OUR E...WITH A WEAKENING TROUGH OVER THE CA COAST. THESE TWO
FEATURES ARE KEEPING A MOIST...S/SELY FLOW IN PLACE ACROSS THE CWA
EARLY TODAY. SATELLITE-ESTIMATED PWATERS ARE STILL AROUND 1.5 INCHES
OVER SCNTRL DESERTS...LESSER AMOUNTS OUT IN WRN CWA. HARD TO SEE ANY
APPRECIABLE FEATURES ON WV THAT COULD POTENTIALLY SERVE TO ENHANCE
CONVECTION TODAY...AND WITH STEERING FLOWS REMAINING OUT OF THE S
AND SW...CONDS STILL NOT ALL THAT FAVORABLE FOR ACTIVITY COMING OFF
THE RIM AND INTERACTING WITH ANY POTENTIAL BOUNDARIES FROM THE S.
STILL...WE SHOULD HAVE LOTS OF INSOLATION TO WORK WITH TODAY TO HELP
US REALIZE SOME CAPE...SO A DECENT BATCH OF TSTMS SHOULD GET GOING
MAINLY OVER THE HIGHER TERRAIN AND THEN DRIFT TOWARDS THE DESERTS.
THEREFORE...WILL OPT TO KEEP POPS IN THE LOW-GRADE MONSOON LEVELS...
IE 10-20 PCNT MOST AREAS E OF THE CO RIVER...WITH HIGHER POPS IN THE
USUALLY CONVECTIVELY ACTIVE MOUNTAINOUS REGIONS TO THE E OF THE
GREATER PHX AREA.
THE AFOREMENTIONED UPPER RIDGE WILL RETROGRADE TO OUR W PER SHORT-
RANGE MODEL GUIDANCE. THIS WILL PUT THE CWA IN A MORE W/NWLY FLOW
OVER THE HOLIDAY WEEKEND. THIS WILL CERTAINLY NOT PORTEND TO ANY
MAJOR MOISTURE INCREASE TO BE SURE...IN FACT WE MAY SEE SOME GRADUAL
DRYING TAKE PLACE WITH THIS PATTERN. WILL LEAVE SLIGHT CHANCES GOING
RIGHT ON THRU THE WEEKEND E OF LOWER CO RIVER VALLEY.
NEXT WEEK...BOTH ECMWF AND GFS ARE CONTINUING TO FORECAST ANOTHER
MAJOR TROUGH TO MOVE OVER THE W COAST. THIS WILL PLACE ALL BUT SE AZ
IN A MUCH DRIER FLOW PATTERN...WHEREBY AT MIDWEEK...WE MAY SEE THE
MOISTURE PUSHED BACK TO JUST SRN GILA COUNTY...OR MAYBE EVEN FURTHER
E. FOR NOW...WILL NOT CALL FOR A TOTAL SCOURING OUT OF MOISTURE
(HARD TO DO THIS TIME OF THE MONSOON)...OPTING TO LEAVE A SLIGHT
CHANCE GOING IN ZONE 24 RIGHT ON THRU THE EXTENDED. IF WE DRY
OUT...OF COURSE WE WILL HAVE A BETTER POTENTIAL OF GETTING HOTTER
AGAIN NEXT WEEK. FOR NOW...WILL KEEP MAX TEMPS FAIRLY CLOSE TO EARLY
JULY NORMS.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
STORM ACTIVITY OVER SOUTH-CENTRAL ARIZONA HAS MAINLY BEEN LIMITED TO
WESTERN MARICOPA COUNTY THROUGH 00Z WITH MODEST ACTIVITY OVER
SOUTHEAST ARIZONA AND VERY LITTLE ACTIVITY OVER THE MOGOLLON RIM.
WITH MID-HIGH DEBRIS CLOUDS HAVING OVERSPREAD THE PHOENIX
AREA...THIS WILL NOT HELP INSTABILITY. HAVE DROPPED THE TEMPO GROUPS
FROM THE KPHX AND KIWA TAFS WHICH HAD DESCRIBED A SCENARIO OF VERY
STRONG WINDS ASSOCIATED WITH OUTFLOW FROM NEARBY STORMS. BELIEVE
THIS WAS OVERDONE AND HAVE OPTED TO INDICATE DISTANT STORMS WITH CB
CLOUD LAYER. WITH ABUNDANT MOISTURE...CANT RULE OUT STORMS AFFECTING
KPHX AND KIWA THIS EVENING BUT CONFIDENCE TOO LOW TO PUT IN TEMPO
GROUPS FOR THUNDERSTORMS AND/OR VERY STRONG WINDS. IF A DISTURBANCE
PROGGED BY THE MODELS PANS OUT...THERE COULD BE LATE NIGHT STORM
ACTIVITY...AFTER 06Z BUT NOT ENOUGH CONFIDENCE IN THIS SCENARIO TO
REFLECT IT IN THE TAFS. WISHY-WASHY SURFACE WINDS SHOULD FAVOR
WESTERLY DIRECTIONS THIS EVENING BEFORE TRANSITIONING TO DOWNVALLEY
FLOW AFTER 07Z.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
ISOLATED TSTMS WILL CONTINUE TO AFFECT THE NORTHERN KOFA MOUNTAINS
AND EASTERN RIVERSIDE COUNTY THROUGH 03Z BEFORE DISSIPATING AND WILL
THREATEN KBLH. THEREAFTER...MOSTLY CLEAR SKIES CAN BE EXPECTED.
STORMS NOT EXPECTED TO IMPACT KIPL. OTHERWISE...SURFACE WINDS SHOULD
FAVOR EAST AND SOUTHEAST DIRECTIONS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...ESTLE
AVIATION...AJ
FIRE WEATHER...VLM
000
FXUS65 KFGZ 030932
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 AM MST FRI JUL 3 2009
.SYNOPSIS...MONSOON MOISTURE WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO NORTHERN ARIZONA TODAY AND OVER THE FOURTH OF JULY
WEEKEND. A DRIER WESTERLY FLOW WILL DEVELOP BY MONDAY WITH A
DECREASE IN THE CHANCE OF SHOWERS. SEASONABLE TEMPERATURES ARE
EXPECTED THROUGH THE PERIOD.
&&
.DISCUSSION...HIGH PRESSURE IN THE MID LEVELS WAS CENTERED OVER THE
NEW MEXICO/TEXAS BORDER DURING THE MORNING HOURS...SHIFTING EASTWARD.
FOR TODAY...THE FLOW ALOFT WILL TURN MORE WESTERLY WITH SOME MID
LEVEL WARMING. DON`T THINK THIS WARMING WILL BE ENOUGH TO CAP OFF
CONVECTION SINCE THE BOUNDARY LAYER REMAINS VERY MOIST. EXPECT THAT
WITH DAYTIME HEATING ANOTHER ROUND OF ISOLATED TO SCATTERED
THUNDERSTORMS WILL DEVELOP. THERE SHOULD BE MORE SUNSHINE TODAY WITH
A FEW MORE STRONGER STORMS THAN ON THURSDAY. THE MAIN THREAT WITH
STRONGER STORMS TODAY WILL BE HEAVY RAIN.
FOR THE WEEKEND INTO EARLY NEXT WEEK...THE MID LEVEL HIGH WILL SHIFT
EAST AND THEN SOUTHWARD WITH WESTERLY FLOW BECOMING MORE PROMINENT
AS A LOW PRESSURE SYSTEM SETS UP OVER THE PACIFIC NORTHWEST. FOR
SATURDAY AND SUNDAY...THE WESTERLY FLOW REMAINS WEAK AND NO
SIGNIFICANT MID LEVEL CAP TO CONVECTION APPEARS IMMINENT. IN
ADDITION...THE BOUNDARY LAYER WILL REMAIN MOIST. SO THE THREAT OF
ISOLATED TO SCATTERED THUNDERSTORMS WILL CONTINUE OVER THE
WEEKEND...MOST NUMEROUS OVER EASTERN PORTIONS OF THE STATE. BY
MONDAY AND TUESDAY...MODELS ARE SHOWING A STRONGER WEST TO SOUTHWEST
FLOW DEVELOPING OVER ARIZONA AS THE PACIFIC NORTHWEST TROUGH
STRENGTHENS. THIS WILL SURELY BRING IN WARMER AND DRIER AIR AND
REDUCE THE CHANCE OF STORMS FURTHER. HOWEVER...LOW LEVEL MOISTURE
WILL REMAIN OVER SOUTHERN ARIZONA WITH THE POTENTIAL FOR INTRUSIONS OF
THIS MOISTURE INTO NORTHERN ARIZONA. AS A RESULT...WILL CONTINUE
WITH A SLIGHT CHANCE OF SHOWERS AND STORMS FOR EARLY NEXT WEEK.
WEDNESDAY AND BEYOND...THE GFS AND EUROPEAN SHOW THE PACIFIC
NORTHWEST LOW WEAKENING AND RETROGRADING OVER THE NORTHEAST PACIFIC.
AT THE SAME TIME HIGH PRESSURE BECOMES REESTABLISHED OVER THE
SOUTHWEST UNITED STATES. THE MAIN DIFFERENCE IS THAT THE EUROPEAN
BUILDS THE HIGH PRESSURE MORE AGGRESSIVELY WITH A STRONG SUGGESTION
OF AN UPTURN IN MONSOON ACTIVITY TOWARD THE END OF NEXT WEEK. ALL
THIS CONSIDERED...WILL HEDGE TOWARD INCREASING POPS FOR THE END OF
NEXT WEEK.
&&
.AVIATION...FOR THE 12Z PACKAGE...SCATTERED SHOWER AND THUNDERSTORM
ACTIVITY EXPECTED TO DEVELOP BY LATE MORNING AND LAST THROUGH THE
AFTERNOON. VFR CONDITIONS IN THE MORNING WILL TRANSITION TO LOCAL
MVFR CONDITIONS IN SCATTERED SHOWER AND THUNDERSTORM ACTIVITY. SOME
OF THE HEAVIER THUNDERSTORMS MAY RESULT IN BRIEF IFR CONDITIONS
FRIDAY AFTERNOON. STORMS ARE FORECAST TO DIMINISH TO ISOLD AFT 04Z
SATURDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...HIGH PRESSURE WILL REMAIN CENTERED TO OUR EAST
THROUGH SATURDAY. THE FLOW AROUND THE HIGH WILL PROVIDE MODERATE
MOISTURE WITH AFTERNOON MINIMUM RELATIVE HUMIDITY REMAINING ABOVE
CRITICAL VALUES. SCATTERED AFTERNOON AND EARLY EVENING SHOWERS AND
THUNDERSTORMS ARE EXPECTED BOTH TODAY AND SATURDAY...ALONG WITH
LOCALIZED GUSTY WINDS IN VICINITY OF THE STRONGER THUNDERSTORMS.
OUTSIDE OF THUNDERSTORM ACTIVITY...WINDS WILL BE LIGHT.
SUNDAY THROUGH TUESDAY...A DRYING TREND IS EXPECTED THROUGH THE
PERIOD AS DEEPER WESTERLY FLOW RESUMES. THE CHANCE FOR AFTERNOON AND
EVENING SHOWER AND THUNDERSTORM ACTIVITY WILL BE LESS THAN 20
PERCENT ACROSS MOST OF NORTHERN ARIZONA...EXCEPT 20-25 PERCENT ALONG
THE MOGOLLON RIM. MINIMUM AFTERNOON RH VALUES WILL RANGE FROM 30-35
PERCENT ACROSS THE WHITE MOUNTAINS TO 10-15 PERCENT ACROSS THE GRAND
CANYON COUNTRY AND KAIBAB PLATEAU. WINDS WILL REMAIN BELOW 15 MPH
THROUGH PERIOD...EXCEPT INCREASING TO NEAR 20 MPH LATE MONDAY AND
TUESDAY ACROSS THE KAIBAB AND COCONINO PLATEAUS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC..................MCCOLLUM
AVIATION/FIRE WEATHER...MAS
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER
INFORMATION.
000
FXUS65 KTWC 030845
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
145 AM MST FRI JUL 3 2009
.SYNOPSIS...ABUNDANT MOISTURE WILL BRING SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS ACROSS SOUTHEAST ARIZONA THROUGH INDEPENDENCE
DAY. AS A TROUGH PROGRESSES TO THE WEST COAST...DRIER AIR WILL MOVE
INTO ARIZONA NEXT WEEK FOR A DECREASE IN MOISTURE AND THUNDERSTORM
ACTIVITY.
&&
.DISCUSSION...CURRENT RADAR SHOWS SHOWER AND THUNDERSTORM ACTIVITY
CONTINUING TO QUIET DOWN AS THE EARLY MORNING HOURS PROGRESS.
CURRENT SATELLITE SHOWS LARGE THUNDERSTORM COMPLEX SOUTH OF THE
INTERNATIONAL BORDER...WHICH SEEMS TO CONTENT TO REMAIN THERE. THIS
WILL END UP IMPACTING THE FORECAST SOMEWHAT BECAUSE EVEN THOUGH THE
STORM ACTUALLY SEEMS TO BE MIGRATING SOUTHWARD...DEBRIS CLOUDS FROM
THIS STORM ARE PUSHING NORTHWARD. DEPENDING HOW MANY OF THESE CLOUDS
REMAIN OVER SOUTHEAST ARIZONA ONCE THE SUN RISES...MAY SEE A DELAYED
START TO ACTIVITY...FOCUSING MAINLY ONCE AGAIN ON STARTING AROUND
MID TO LATE AFTERNOON. HAVE TRIED TO ALTER INHERITED FORECAST TO
TAKE THIS INTO ACCOUNT.
MODEL DATA CONTINUES TO SHOW ENOUGH MOISTURE FOR CONTINUED ACTIVITY
FOR THE END OF THE WEEK AND INTO THE WEEKEND BEFORE DRIER AIR BEGINS
TO WORK IN BY LATE IN THE WEEKEND AND THE START OF NEXT WEEK. FOR
THE NEAR TERM...NAM SHOWS AN ACTIVE FRIDAY AND SUNDAY WITH A DOWN
SATURDAY. AGREE WITH ACTIVE FRIDAY BUT CANNOT SEE THE REASONING FOR
A DOWNTURN IN ACTIVITY FOR SATURDAY. WHILE CANNOT RULE OUT THE
CHANCE OF GETTING WORKED OVER BY CLOUDS...NOT SOMETHING COMFORTABLE
DOING UNTIL CAN SEE THE WHITES OF ITS EYES...SO TO SPEAK.
INSTEAD...OPTED TO SIDE WITH INHERITED FORECAST SHOWING A GRADUAL
DRYING TREND. TRANSITIONING TO MID AND LONG TERM...GFS SHOWS DRIER
AIR REMAINING IN PLACE FOR THE FIRST HALF OF NEXT WEEK AS A TROF
SITS OVER THE PACIFIC NORTHWEST...BLOCKING HIGH PRESSURE FROM THE
FOUR CORNERS REGION. STILL IN A POSITION TO PULL SOME MOISTURE INTO
PORTIONS OF CWA FROM MAINLY TUCSON METRO EAST...SO WILL LEAVE SLIGHT
CHANCE POPS THERE. POPS WILL SLOWLY REBOUND FROM MID WEEK ON AS HIGH
PRESSURE SLOWLY WOBBLES BACK TOWARD THE STATE.
VERY LONG WAY OF SAYING NO SIGNIFICANT CHANGES TO FORECAST PLANNED
AT THIS TIME.
&&
.AVIATION...SCATTERED TSRA/SHRA EXPECTED THIS EARLY MORNING...MAINLY
EAST OF KTUS. LOW BROKEN CLOUD DECKS EXPECTED TO REMAIN IN PLACE
OVER KDUG AND KOLS THROUGH MUCH OF EARLY MORNING AS STRONG STORM
SOUTH OF THE INTERNATIONAL BORDER CONTINUES. SCATTERED TO BROKEN MID
LEVEL CLOUD DECKS CAN BE EXPECTED NORTH OF A LINE FROM KTUS TO KSAD.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL STILL BE POSSIBLE
NEAR KDUG AND KOLS THROUGH 10Z. WINDS NEAR THESE SITES MAY HAVE
ERRATIC WIND GUSTS TO 40 MPH DUE TO OUTFLOW FROM MEXICAN STORM.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A MOIST ATMOSPHERE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SCATTERED THUNDERSTORMS THROUGH THE WEEKEND. A TROUGH
MOVING TOWARDS THE WEST COAST WILL SHIFT A DRIER WESTERLY FLOW INTO
ARIZONA NEXT WEEK...ALTHOUGH ENOUGH MOISTURE SHOULD REMAIN IN PLACE
TO MINIMIZE ANY FIRE WEATHER RISKS AND CONCERNS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KPSR 030500
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1000 PM MST THU JUL 2 2009
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
STORM ACTIVITY HAS TRAILED OFF CONSIDERABLY AND ONLY WEAK ISOLATED
STORMS ARE LEFT OVER ARIZONA AND SOUTHEAST CALIFORNIA. THERE IS A
CONSIDERABLE AMOUNT OF MOISTURE AROUND WITH PRECIPITABLE WATER
VALUES OF 1.4-1.7 INCHES ON THE LOWER ELEVATIONS. HOWEVER...00Z AND
03Z PSR SOUNDINGS SHOW WARM MID LEVELS INHIBITING INSTABILITY. IF A
DISTURBANCE CAN MOVE THROUGH TONIGHT AS INDICATED BY THE RUC THEN A
NOCTURNAL PRECIP EVENT IS STILL POSSIBLE...THOUGH IT ONLY ADVERTISES
A BRUSH-BY FOR EASTERN ZONE 24 AFTER 12Z. IF THIS FEATURE HAD
SUFFICIENT LIFT WOULD ALSO EXPECT TO SEE MORE STORM ACTIVITY OVER
SOUTHEAST ARIZONA BY NOW. GFS AND NAM ARE NOT DEPICTING ANY COHERENT
FEATURES CREATING PROLONGED VERTICAL MOTIONS. WILL HANG ON TO
LINGERING SLIGHT CHANCES BUT WITH SOME MODIFICATIONS.
MODELS MAINTAIN FAIRLY HIGH MOISTURE VALUES THROUGH THE WEEKEND
BEFORE BEGINNING TO DRY FROM THE WEST. NEITHER GFS NOR NAM INDICATE
BIG IMPROVEMENTS TO INSTABILITY PER FORECAST SOUNDINGS. SO IT WILL
BE DIFFICULT TO PINPOINT ANY LARGE UPSWINGS OR DOWNSWINGS OVER THE
NEXT 2-3 DAYS.
PREVIOUS DISCUSSION...
LATEST THINKING REMAINS CONSISTENT FROM THIS MORNING (SEE BELOW).
THUNDERSTORMS HAVE INDEED DEVELOPED ACROSS THE SOUTHWEST DESERTS
AHEAD OF A CYCLONICALLY CURVED VORT LOBE ALONG THE CO RIVER VALLEY.
MODIFIED YUMA SOUNDING GENERATES CAPE ~700 J/KG LIFTING FROM 975 MB
FOR THIS AFTERNOON. STEERING FLOW AROUND THE RIDGE WILL ADVECT THIS
ACTIVITY SLOWLY NORTH AND NORTHEASTWARD...SO ACTIVITY CURRENTLY NEAR
GILA BEND CERTAINLY HAS THE POTENTIAL TO DRIFT TOWARDS THE PHOENIX
METRO AREA EARLY THIS EVENING. STORMS HAVE NOT LOOKED ALL THAT
IMPRESSIVE ON RADAR WITH REGARDS TO SEVERE WINDS/HAIL...THOUGH GUSTY
WINDS IN EXCESS OF 50 MPH ARE POSSIBLE WITH THE STRONGEST CELLS.
WITH PWATS >1.5 INCHES...HEAVY RAIN AND FLOODING MAY TURN OUT TO BE
THE BIGGER THREAT.
CONFIDENCE HAS INCREASED FOR THIS EVENING BASED ON THE 12Z GFS. MCS
IS EXPECTED TO DEVELOP SOUTHEAST OF THE FORECAST AREA...BEFORE
DRIFTING NORTHWARD TONIGHT. MAV POPS HAVE INCREASED AND HIGHLIGHT
THE 06Z-12Z PERIOD AS THE MOST FAVORABLE. ACTIVITY MAY ACTUALLY
CARRY OVER INTO TOMORROW MORNING AND HAVE RAISED POPS CONSIDERABLY
FOR 12Z-18Z FRI. CONSEQUENTLY...LOWER TEMPS ARE EXPECTED WITH HIGH
TEMPS NEAR 100 DEGREES IN PHOENIX.
EXCERPTS FROM MORNING DISCUSSION...
AS WAS THE CASE YESTERDAY...EXTENSIVE CLOUD COVER WILL DELAY THE
ONSET OF CONVECTION THIS AFTERNOON ALONG THE MOGOLLON RIM. ACROSS
THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY CLEAR WITH DEWPOINTS IN
THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST THE ATMOSPHERE WILL BE
UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS THUNDERSTORMS WITHOUT
MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM YUMA TO GILA BEND AND
STRETCHING NORTHWARD INTO THE MOJAVE DESERT...WHERE A VORT LOBE IS
ALREADY PRODUCING MORNING THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
EXTENDED...
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
STORM ACTIVITY OVER SOUTH-CENTRAL ARIZONA HAS MAINLY BEEN LIMITED TO
WESTERN MARICOPA COUNTY THROUGH 00Z WITH MODEST ACTIVITY OVER
SOUTHEAST ARIZONA AND VERY LITTLE ACTIVITY OVER THE MOGOLLON RIM.
WITH MID-HIGH DEBRIS CLOUDS HAVING OVERSPREAD THE PHOENIX
AREA...THIS WILL NOT HELP INSTABILITY. HAVE DROPPED THE TEMPO GROUPS
FROM THE KPHX AND KIWA TAFS WHICH HAD DESCRIBED A SCENARIO OF VERY
STRONG WINDS ASSOCIATED WITH OUTFLOW FROM NEARBY STORMS. BELIEVE
THIS WAS OVERDONE AND HAVE OPTED TO INDICATE DISTANT STORMS WITH CB
CLOUD LAYER. WITH ABUNDANT MOISTURE...CANT RULE OUT STORMS AFFECTING
KPHX AND KIWA THIS EVENING BUT CONFIDENCE TOO LOW TO PUT IN TEMPO
GROUPS FOR THUNDERSTORMS AND/OR VERY STRONG WINDS. IF A DISTURBANCE
PROGGED BY THE MODELS PANS OUT...THERE COULD BE LATE NIGHT STORM
ACTIVITY...AFTER 06Z BUT NOT ENOUGH CONFIDENCE IN THIS SCENARIO TO
REFLECT IT IN THE TAFS. WISHY-WASHY SURFACE WINDS SHOULD FAVOR
WESTERLY DIRECTIONS THIS EVENING BEFORE TRANSITIONING TO DOWNVALLEY
FLOW AFTER 07Z.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
ISOLATED TSTMS WILL CONTINUE TO AFFECT THE NORTHERN KOFA MOUNTAINS
AND EASTERN RIVERSIDE COUNTY THROUGH 03Z BEFORE DISSIPATING AND WILL
THREATEN KBLH. THEREAFTER...MOSTLY CLEAR SKIES CAN BE EXPECTED.
STORMS NOT EXPECTED TO IMPACT KIPL. OTHERWISE...SURFACE WINDS SHOULD
FAVOR EAST AND SOUTHEAST DIRECTIONS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...AJ
FIRE WEATHER...VLM
000
FXUS65 KFGZ 030417
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
915 PM MST THU JUL 2 2009
.SYNOPSIS...MONSOON FLOW WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO NORTHERN ARIZONA FROM TODAY INTO THE HOLIDAY
WEEKEND. SEASONABLE TEMPERATURES ARE EXPECTED THROUGH THE PERIOD.
&&
.DISCUSSION...ZONE AND GRIDDED FORECAST HAVE BEEN UPDATED TO REFLECT
THE REDUCTION IN SHOWER AND THUNDERSTORM ACTIVITY THIS EVENING AND
DURING THE OVERNIGHT TIME PERIOD. EXPECT MORE SCATTERED SHOWER AND
THUNDERSTORM ACTIVITY TO DEVELOP OVER THE HIGHER TERRAIN FRIDAY
AFTERNOON AND CONTINUE INTO THE EVENING HOURS IN THE LITTLE COLORADO
RIVER VALLEY AND THE VALLEYS AND MOUNTAINS OF YAVAPAI COUNTY AND
NORTHERN GILA COUNTY.
&&
.PREVIOUS DISCUSSION /300 PM MST/...MID-LEVEL HIGH PRESSURE CENTERED
NEAR EASTERN NEW MEXICO WILL CONTINUE TO ALLOW A MOIST MONSOONAL
FLOW OVER THE REGION FOR THE REMAINDER OF TODAY AND AGAIN ON FRIDAY.
WITH PRECIPITABLE WATER VALUES NEAR 1 INCH AT FLAGSTAFF THROUGH THE
MORNING AND EARLY AFTERNOON...THUNDERSTORMS HAVE DEVELOPED ACROSS
MUCH OF THE NORTHLAND...THOUGH THE STRENGTH OF THESE STORMS HAS BEEN
LIMITED THUS FAR TO BELOW SEVERE LEVELS.
FAVORABLE MOISTURE FOR PRECIPITATION SHOULD REMAIN THROUGH THE END
OF THE WEEK...WITH A DRIER SOUTHWESTERLY FLOW ALOFT DEVELOPING BY
LATE IN THE WEEKEND AND EARLY NEXT WEEK. PRECIP CHANCES ARE LESSER
DURING THIS TIME FRAME...ALTHOUGH SLIGHT CHANCES FOR THUNDERSTORMS
STILL SEEM WARRANTED.
IN ALL...KEEPING NEAR SEASONABLE DAYTIME TEMPERATURES AND PRECIP
CHANCES THROUGH THE MAJORITY OF THE 7-DAY FORECAST.
&&
.AVIATION...FOR THE 06Z PACKAGE...ISOLATED SHOWERS AND THUNDERSTORMS
WILL CONTINUE OVERNIGHT WITH ANY REMAINING CIGS AOA 10 KFT THROUGH
THE OVERNIGHT PERIOD. FOR FRIDAY...FORECAST SOUNDINGS SUGGEST
SCATTERED SHOWER AND THUNDERSTORM ACTIVITY TO DEVELOP BY LATE
MORNING AND LAST THROUGH THE AFTERNOON. VFR CONDITIONS IN THE
MORNING WILL TRANSITION TO LOCAL MVFR CONDITIONS IN SCATTERED SHOWER
AND THUNDERSTORM ACTIVITY. SOME OF THE HEAVIER THUNDERSTORMS MAY
RESULT IN BRIEF IFR CONDITIONS FRIDAY AFTERNOON. STORMS ARE FORECAST
TO DIMINISH TO ISOLD AFT 04Z SATURDAY. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...THROUGH SATURDAY...HIGH PRESSURE WILL REMAIN
CENTERED TO OUR EAST...AND RESULTING FLOW AROUND THE HIGH WILL
PROVIDE MODERATE MOISTURE PROFILES WITH AFTERNOON MINIMUM RELATIVE
HUMIDITY REMAINING ABOVE CRITICAL VALUES. SCATTERED AFTERNOON AND
EARLY EVENING SHOWERS AND THUNDERSTORMS ARE EXPECTED BOTH FRIDAY AND
SATURDAY...ALONG WITH LOCALIZED GUSTY WINDS IN VICINITY OF THE
STRONGER THUNDERSTORMS. OUTSIDE OF THUNDERSTORM ACTIVITY...WINDS
WILL BE LIGHT.
SUNDAY THROUGH TUESDAY...A DRYING TREND IS EXPECTED THROUGH THE
PERIOD AS DEEPER WESTERLY FLOW RESUMES. THE CHANCE FOR AFTERNOON AND
EVENING SHOWER AND THUNDERSTORM ACTIVITY WILL BE LESS THAN 20
PERCENT ACROSS MOST OF NORTHERN ARIZONA...EXCEPT 20-25 PERCENT ALONG
THE MOGOLLON RIM. MINIMUM AFTERNOON RH VALUES WILL RANGE FROM 30-35
PERCENT ACROSS THE WHITE MOUNTAINS TO 10-15 PERCENT ACROSS THE GRAND
CANYON COUNTRY AND KAIBAB PLATEAU. WINDS WILL REMAIN BELOW 15 MPH
THROUGH PERIOD...EXCEPT INCREASING TO NEAR 20 MPH LATE MONDAY AND
TUESDAY ACROSS THE KAIBAB AND COCONINO PLATEAUS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC..................TC/KD
AVIATION/FIRE WEATHER...TC/PETRO
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER
INFORMATION.
000
FXUS65 KTWC 030344
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
900 PM MST THU JUL 2 2009
.SYNOPSIS...ABUNDANT MOISTURE WILL BRING SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS ACROSS SOUTHEAST ARIZONA THROUGH INDEPENDENCE
DAY. AS A TROUGH PROGRESSES TO THE WEST COAST...DRIER AIR WILL MOVE
INTO ARIZONA NEXT WEEK FOR A DECREASE IN MOISTURE AND THUNDERSTORM
ACTIVITY.
&&
.DISCUSSION...SCATTERED TO NUMEROUS SHOWER AND THUNDERSTORM COVERAGE
EARLIER STARTING TO WANE A LITTLE. IMPULSE WRAPPING AROUND THE HIGH
THROUGH SONORA WILL HELP FOCUS SOME NOCTURNAL ACTIVITY. DEEPER
MOISTURE IN PLACE IN SOUTHERLY TO SOUTHEASTERLY CIRCULATION AROUND
HIGH. SURFACE DEWPTS IN THE MID 50S TO 60S AND WHILE THE 00Z KTUS
SOUNDING ONLY CAME IN AT 1.41 INCHES...GOES SOUNDER ESTIMATES HAVE
THE TREND UP OVER THE PAST 3 TO 6 HOURS. CURRENT FORECAST MAY BE A
LITTLE LIGHT ON AFTERNOON AND EVENING POPS FOR FRIDAY...BUT GOOD
TRENDS WITH BUSY TIME THE NEXT 48 HOURS.
&&
.AVIATION...SCATTERED TSRA/SHRA EXPECTED TONIGHT AND EARLY TOMORROW.
THUNDERSTORMS WILL HAVE ERRATIC WIND GUSTS TO 40 MPH...LIGHTNING AND
LOCALLY HEAVY RAIN WITH REDUCED VISIBILITIES DOWN TO 2SM FOR A BRIEF
PERIOD OF TIME. CLOUD BASES GENERALLY 8-12K FT AGL WITH CEILINGS
NEAR 3K FT AGL AROUND THE THUNDERSTORMS. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A MOIST ATMOSPHERE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SCATTERED THUNDERSTORMS THROUGH THE WEEKEND. A TROUGH
MOVING TOWARDS THE WEST COAST WILL SHIFT A DRIER WESTERLY FLOW INTO
ARIZONA NEXT WEEK.
&&
.PREV DISCUSSION...SYNOPTIC PATTERN HAS A HIGH CENTERED IN NORTHERN
NEW MEXICO WITH MOISTURE ROTATING CLOCKWISE FROM MEXICO INTO
ARIZONA. THIS SITUATION PROVIDES A WEAK DIVERGENT FLOW ALOFT OVER
SOUTHERN ARIZONA WHICH HAS HELPED SUPPORT THE LATE EVENING AND EARLY
MORNING RAIN SHOWERS THE PAST TWO DAYS. ADDITIONALLY A WEAK UPPER
LEVEL LOW IS LOCATED IN SOUTHERN CHIHUAHUA MEXICO AND MOVING TOWARDS
THE NORTHWEST. CONVECTIVE ACTIVITY IS USUALLY NOT ASSOCIATED WITH
THE CENTER OF THESE LOWS...BUT IN THE DIVERGENT ZONE AHEAD OF THE
SYSTEM. SATELLITE IMAGERY SHOWS THIS CONVECTIVE ACTIVITY BEING
ENHANCED AHEAD OF THE SYSTEM NOW AT 2 PM. THE MODELS ARE NOT PICKING
UP THE EXACT DETAILS ASSOCIATED WITH THIS LOW...BUT DO HAVE THE
GENERAL IDEA OF ORGANIZED CONVECTION MOVING INTO ARIZONA OR NEW
MEXICO EARLY FRIDAY MORNING. LIKEWISE MOS POPS ARE IN THE 40-60
RANGE WHICH IS WELL ABOVE NORMAL.
GIVEN THE ABOVE SITUATION HAVE SIGNIFICANTLY INCREASED POPS FOR
TONIGHT AND TOMORROW MORNING ACROSS EASTERN PIMA...PINAL...SANTA
CRUZ...COCHISE...GRAHAM AND GREENLEE COUNTIES. LIKEWISE INCREASED
QPF AMOUNTS AND DROPPED HIGH TEMPERATURES SLIGHTLY FOR TOMORROW.
AS A MID-LATITUDE TROUGH PROGRESSES TO THE WEST COAST...A WESTERLY
FLOW WITH DRIER AIR IS PROGGED TO INFLUENCE ARIZONA EARLY NEXT WEEK.
THE HIGH OVER THE SOUTHWEST MOVES SOUTH INTO NORTHERN MEXICO AS THIS
TROUGH APPROACHES. THE MODELS VARY ON THE TIMING OF THIS DRY AIR
MOVING INTO US. THE GFS IS FASTER IN DRYING US OUT...THE NAM KEEPS
THE MOISTURE LONGER. GIVEN LARGE SCALE CHANGES HAPPEN
SLOWLY...EXPECT DRIER AIR TO START REDUCING THE CONVECTION ON
SUNDAY. DO NOT EXPECT THE ATMOSPHERE TO DRY OUT ENTIRELY...BUT
THUNDERSTORMS WILL GO FROM SCATTERED TO MORE ISOLATED. LIKEWISE AS
THE ATMOSPHERE DRIES OUT A BIT...MAXIMUM TEMPERATURES WILL INCREASE
SLIGHTLY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/TUCSON
000
FXUS65 KPSR 030036 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
535 PM MST THU JUL 2 2009
.UPDATE...
UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LATEST THINKING REMAINS CONSISTENT FROM THIS MORNING (SEE BELOW).
THUNDERSTORMS HAVE INDEED DEVELOPED ACROSS THE SOUTHWEST DESERTS
AHEAD OF A CYCLONICALLY CURVED VORT LOBE ALONG THE CO RIVER VALLEY.
MODIFIED YUMA SOUNDING GENERATES CAPE ~700 J/KG LIFTING FROM 975 MB
FOR THIS AFTERNOON. STEERING FLOW AROUND THE RIDGE WILL ADVECT THIS
ACTIVITY SLOWLY NORTH AND NORTHEASTWARD...SO ACTIVITY CURRENTLY NEAR
GILA BEND CERTAINLY HAS THE POTENTIAL TO DRIFT TOWARDS THE PHOENIX
METRO AREA EARLY THIS EVENING. STORMS HAVE NOT LOOKED ALL THAT
IMPRESSIVE ON RADAR WITH REGARDS TO SEVERE WINDS/HAIL...THOUGH GUSTY
WINDS IN EXCESS OF 50 MPH ARE POSSIBLE WITH THE STRONGEST CELLS.
WITH PWATS >1.5 INCHES...HEAVY RAIN AND FLOODING MAY TURN OUT TO BE
THE BIGGER THREAT.
CONFIDENCE HAS INCREASED FOR THIS EVENING BASED ON THE 12Z GFS. MCS
IS EXPECTED TO DEVELOP SOUTHEAST OF THE FORECAST AREA...BEFORE
DRIFTING NORTHWARD TONIGHT. MAV POPS HAVE INCREASED AND HIGHLIGHT
THE 06Z-12Z PERIOD AS THE MOST FAVORABLE. ACTIVITY MAY ACTUALLY
CARRY OVER INTO TOMORROW MORNING AND HAVE RAISED POPS CONSIDERABLY
FOR 12Z-18Z FRI. CONSEQUENTLY...LOWER TEMPS ARE EXPECTED WITH HIGH
TEMPS NEAR 100 DEGREES IN PHOENIX.
EXCERPTS FROM MORNING DISCUSSION...
AS WAS THE CASE YESTERDAY...EXTENSIVE CLOUD COVER WILL DELAY THE
ONSET OF CONVECTION THIS AFTERNOON ALONG THE MOGOLLON RIM. ACROSS
THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY CLEAR WITH DEWPOINTS IN
THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST THE ATMOSPHERE WILL BE
UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS THUNDERSTORMS WITHOUT
MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM YUMA TO GILA BEND AND
STRETCHING NORTHWARD INTO THE MOJAVE DESERT...WHERE A VORT LOBE IS
ALREADY PRODUCING MORNING THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
EXTENDED...
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
STORM ACTIVITY OVER SOUTH-CENTRAL ARIZONA HAS MAINLY BEEN LIMITED TO
WESTERN MARICOPA COUNTY THROUGH 00Z WITH MODEST ACTIVITY OVER
SOUTHEAST ARIZONA AND VERY LITTLE ACTIVITY OVER THE MOGOLLON RIM.
WITH MID-HIGH DEBRIS CLOUDS HAVING OVERSPREAD THE PHOENIX
AREA...THIS WILL NOT HELP INSTABILITY. HAVE DROPPED THE TEMPO GROUPS
FROM THE KPHX AND KIWA TAFS WHICH HAD DESCRIBED A SCENARIO OF VERY
STRONG WINDS ASSOCIATED WITH OUTFLOW FROM NEARBY STORMS. BELIEVE
THIS WAS OVERDONE AND HAVE OPTED TO INDICATE DISTANT STORMS WITH CB
CLOUD LAYER. WITH ABUNDANT MOISTURE...CANT RULE OUT STORMS AFFECTING
KPHX AND KIWA THIS EVENING BUT CONFIDENCE TOO LOW TO PUT IN TEMPO
GROUPS FOR THUNDERSTORMS AND/OR VERY STRONG WINDS. IF A DISTURBANCE
PROGGED BY THE MODELS PANS OUT...THERE COULD BE LATE NIGHT STORM
ACTIVITY...AFTER 06Z BUT NOT ENOUGH CONFIDENCE IN THIS SCENARIO TO
REFLECT IT IN THE TAFS. WISHY-WASHY SURFACE WINDS SHOULD FAVOR
WESTERLY DIRECTIONS THIS EVENING BEFORE TRANSITIONING TO DOWNVALLEY
FLOW AFTER 07Z.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
ISOLATED TSTMS WILL CONTINUE TO AFFECT THE NORTHERN KOFA MOUNTAINS
AND EASTERN RIVERSIDE COUNTY THROUGH 03Z BEFORE DISSIPATING AND WILL
THREATEN KBLH. THEREAFTER...MOSTLY CLEAR SKIES CAN BE EXPECTED.
STORMS NOT EXPECTED TO IMPACT KIPL. OTHERWISE...SURFACE WINDS SHOULD
FAVOR EAST AND SOUTHEAST DIRECTIONS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...AJ
FIRE WEATHER...VLM
000
FXUS65 KPSR 022218 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
317 PM MST THU JUL 2 2009
.UPDATE...UPDATED AVIATION DISCUSSIONS.
&&
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LATEST THINKING REMAINS CONSISTENT FROM THIS MORNING (SEE BELOW).
THUNDERSTORMS HAVE INDEED DEVELOPED ACROSS THE SOUTHWEST DESERTS
AHEAD OF A CYCLONICALLY CURVED VORT LOBE ALONG THE CO RIVER VALLEY.
MODIFIED YUMA SOUNDING GENERATES CAPE ~700 J/KG LIFTING FROM 975 MB
FOR THIS AFTERNOON. STEERING FLOW AROUND THE RIDGE WILL ADVECT THIS
ACTIVITY SLOWLY NORTH AND NORTHEASTWARD...SO ACTIVITY CURRENTLY NEAR
GILA BEND CERTAINLY HAS THE POTENTIAL TO DRIFT TOWARDS THE PHOENIX
METRO AREA EARLY THIS EVENING. STORMS HAVE NOT LOOKED ALL THAT
IMPRESSIVE ON RADAR WITH REGARDS TO SEVERE WINDS/HAIL...THOUGH GUSTY
WINDS IN EXCESS OF 50 MPH ARE POSSIBLE WITH THE STRONGEST CELLS.
WITH PWATS >1.5 INCHES...HEAVY RAIN AND FLOODING MAY TURN OUT TO BE
THE BIGGER THREAT.
CONFIDENCE HAS INCREASED FOR THIS EVENING BASED ON THE 12Z GFS. MCS
IS EXPECTED TO DEVELOP SOUTHEAST OF THE FORECAST AREA...BEFORE
DRIFTING NORTHWARD TONIGHT. MAV POPS HAVE INCREASED AND HIGHLIGHT
THE 06Z-12Z PERIOD AS THE MOST FAVORABLE. ACTIVITY MAY ACTUALLY
CARRY OVER INTO TOMORROW MORNING AND HAVE RAISED POPS CONSIDERABLY
FOR 12Z-18Z FRI. CONSEQUENTLY...LOWER TEMPS ARE EXPECTED WITH HIGH
TEMPS NEAR 100 DEGREES IN PHOENIX.
EXCERPTS FROM MORNING DISCUSSION...
AS WAS THE CASE YESTERDAY...EXTENSIVE CLOUD COVER WILL DELAY THE
ONSET OF CONVECTION THIS AFTERNOON ALONG THE MOGOLLON RIM. ACROSS
THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY CLEAR WITH DEWPOINTS IN
THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST THE ATMOSPHERE WILL BE
UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS THUNDERSTORMS WITHOUT
MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM YUMA TO GILA BEND AND
STRETCHING NORTHWARD INTO THE MOJAVE DESERT...WHERE A VORT LOBE IS
ALREADY PRODUCING MORNING THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
EXTENDED...
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
EARLY AFTERNOON HEATING RESULTED IN A CLUSTER OF STRONG TSTMS IN
VICINITY OF KGBN AND SOUTHWARD INTO PIMA COUNTY. TSTMS FIRED AND
DISSIPATED RATHER QUICKLY...AND ADDITIONAL CONVECTION EARLY THIS
EVENING IS POSSIBLE ALTHO SFC DEW POINTS HOLDING STEADY IN THE UPPER
50S. WILL EXPECT AT LEAST ONE OUTFLOW BOUNDARY TO IMPACT KPHX AND
KIWA FOR 2-4 MILES VSBYS. AN INCREASING CHANCE OF STORMS IS STILL
POSSIBLE AFTER DARK...THROUGH ABOUT 06Z.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
ISOLATED TSTMS WITH WIND GUSTS TO 40 KTS NEAR KBLH TIL 23Z BUT
STORMS WILL LIKELY DISSIPATE QUICKLY AFTER DARK. WINDS NOT EXPECTED
TO BE SIGNIFICANT TONIGHT INTO FRIDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...SIPPLE
FIRE WEATHER...VLM
000
FXUS65 KFGZ 022201
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
300 PM MST THU JUL 2 2009
.SYNOPSIS...MONSOON FLOW WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO NORTHERN ARIZONA FROM TODAY INTO THE HOLIDAY
WEEKEND. SEASONABLE TEMPERATURES ARE EXPECTED THROUGH THE PERIOD.
&&
.DISCUSSION...MID-LEVEL HIGH PRESSURE CENTERED NEAR EASTERN NEW
MEXICO WILL CONTINUE TO ALLOW A MOIST MONSOONAL FLOW OVER THE REGION
FOR THE REMAINDER OF TODAY AND AGAIN ON FRIDAY. WITH PRECIPITABLE
WATER VALUES NEAR 1 INCH AT FLAGSTAFF THROUGH THE MORNING AND EARLY
AFTERNOON...THUNDERSTORMS HAVE DEVELOPED ACROSS MUCH OF THE
NORTHLAND...THOUGH THE STRENGTH OF THESE STORMS HAS BEEN LIMITED
THUS FAR TO BELOW SEVERE LEVELS.
FAVORABLE MOISTURE FOR PRECIPITATION SHOULD REMAIN THROUGH THE END
OF THE WEEK...WITH A DRIER SOUTHWESTERLY FLOW ALOFT DEVELOPING BY
LATE IN THE WEEKEND AND EARLY NEXT WEEK. PRECIP CHANCES ARE LESSER
DURING THIS TIME FRAME...ALTHOUGH SLIGHT CHANCES FOR THUNDERSTORMS
STILL SEEM WARRANTED.
IN ALL...KEEPING NEAR SEASONABLE DAYTIME TEMPERATURES AND PRECIP
CHANCES THROUGH THE MAJORITY OF THE 7-DAY FORECAST.
&&
.AVIATION...FOR THE 00Z PACKAGE...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL CONTINUE THROUGH THE EVENING...THEN TAPER OFF
WITH ANY REMAINING CIGS AOA 10 KFT THROUGH THE OVERNIGHT PERIOD.
FOR FRIDAY...FORECAST SOUNDINGS SUGGEST SCATTERED SHOWER AND
THUNDERSTORM ACTIVITY TO DEVELOP BY LATE MORNING AND LAST THROUGH
THE AFTERNOON. VFR CONDITIONS IN THE MORNING WILL TRANSITION TO
LOCAL MVFR CONDITIONS IN SCATTERED SHOWER AND THUNDERSTORM ACTIVITY.
SOME OF THE HEAVIER THUNDERSTORMS MAY RESULT IN BRIEF IFR CONDITIONS
FRIDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...THROUGH SATURDAY...HIGH PRESSURE WILL REMAIN
CENTERED TO OUR EAST...AND RESULTING FLOW AROUND THE HIGH WILL
PROVIDE MODERATE MOISTURE PROFILES WITH AFTERNOON MINIMUM RELATIVE
HUMIDITY REMAINING ABOVE CRITICAL VALUES. SCATTERED AFTERNOON AND
EARLY EVENING SHOWERS AND THUNDERSTORMS ARE EXPECTED BOTH FRIDAY AND
SATURDAY...ALONG WITH LOCALIZED GUSTY WINDS IN VICINITY OF THE
STRONGER THUNDERSTORMS. OUTSIDE OF THUNDERSTORM ACTIVITY...WINDS
WILL BE LIGHT.
SUNDAY THROUGH TUESDAY...A DRYING TREND IS EXPECTED THROUGH THE
PERIOD AS DEEPER WESTERLY FLOW RESUMES. THE CHANCE FOR AFTERNOON AND
EVENING SHOWER AND THUNDERSTORM ACTIVITY WILL BE LESS THAN 20
PERCENT ACROSS MOST OF NORTHERN ARIZONA...EXCEPT 20-25 PERCENT ALONG
THE MOGOLLON RIM. MINIMUM AFTERNOON RH VALUES WILL RANGE FROM 30-35
PERCENT ACROSS THE WHITE MOUNTAINS TO 10-15 PERCENT ACROSS THE GRAND
CANYON COUNTRY AND KAIBAB PLATEAU. WINDS WILL REMAIN BELOW 15 MPH
THROUGH PERIOD...EXCEPT INCREASING TO NEAR 20 MPH LATE MONDAY AND
TUESDAY ACROSS THE KAIBAB AND COCONINO PLATEAUS.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC..................KD
AVIATION/FIRE WEATHER...PETRO
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER
INFORMATION.
000
FXUS65 KTWC 022141
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
240 PM MST THU JUL 2 2009
.SYNOPSIS...ABUNDANT MOISTURE WILL BRING SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS ACROSS SOUTHEAST ARIZONA THROUGH INDEPENDENCE
DAY. AS A TROUGH PROGRESSES TO THE WEST COAST...DRIER AIR WILL MOVE
INTO ARIZONA NEXT WEEK FOR A DECREASE IN MOISTURE AND THUNDERSTORM
ACTIVITY.
&&
.DISCUSSION...SYNOPTIC PATTERN HAS A HIGH CENTERED IN NORTHERN NEW
MEXICO WITH MOISTURE ROTATING CLOCKWISE FROM MEXICO INTO ARIZONA.
THIS SITUATION PROVIDES A WEAK DIVERGENT FLOW ALOFT OVER SOUTHERN
ARIZONA WHICH HAS HELPED SUPPORT THE LATE EVENING AND EARLY MORNING
RAIN SHOWERS THE PAST TWO DAYS. ADDITIONALLY A WEAK UPPER LEVEL LOW
IS LOCATED IN SOUTHERN CHIHUAHUA MEXICO AND MOVING TOWARDS THE
NORTHWEST. CONVECTIVE ACTIVITY IS USUALLY NOT ASSOCIATED WITH THE
CENTER OF THESE LOWS...BUT IN THE DIVERGENT ZONE AHEAD OF THE
SYSTEM. SATELLITE IMAGERY SHOWS THIS CONVECTIVE ACTIVITY BEING
ENHANCED AHEAD OF THE SYSTEM NOW AT 2 PM. THE MODELS ARE NOT
PICKING UP THE EXACT DETAILS ASSOCIATED WITH THIS LOW...BUT DO
HAVE THE GENERAL IDEA OF ORGANIZED CONVECTION MOVING INTO ARIZONA OR
NEW MEXICO EARLY FRIDAY MORNING. LIKEWISE MOS POPS ARE IN THE 40-60
RANGE WHICH IS WELL ABOVE NORMAL.
GIVEN THE ABOVE SITUATION HAVE SIGNIFICANTLY INCREASED POPS FOR
TONIGHT AND TOMORROW MORNING ACROSS EASTERN PIMA...PINAL...SANTA
CRUZ...COCHISE...GRAHAM AND GREENLEE COUNTIES. LIKEWISE INCREASED
QPF AMOUNTS AND DROPPED HIGH TEMPERATURES SLIGHTLY FOR TOMORROW.
AS A MID-LATITUDE TROUGH PROGRESSES TO THE WEST COAST...A WESTERLY
FLOW WITH DRIER AIR IS PROGGED TO INFLUENCE ARIZONA EARLY NEXT WEEK.
THE HIGH OVER THE SOUTHWEST MOVES SOUTH INTO NORTHERN MEXICO AS THIS
TROUGH APPROACHES. THE MODELS VARY ON THE TIMING OF THIS DRY AIR
MOVING INTO US. THE GFS IS FASTER IN DRYING US OUT...THE NAM KEEPS
THE MOISTURE LONGER. GIVEN LARGE SCALE CHANGES HAPPEN
SLOWLY...EXPECT DRIER AIR TO START REDUCING THE CONVECTION ON
SUNDAY. DO NOT EXPECT THE ATMOSPHERE TO DRY OUT ENTIRELY...BUT
THUNDERSTORMS WILL GO FROM SCATTERED TO MORE ISOLATED. LIKEWISE AS
THE ATMOSPHERE DRIES OUT A BIT...MAXIMUM TEMPERATURES WILL INCREASE
SLIGHTLY.
&&
.AVIATION...SCATTERED TSRA/SHRA EXPECTED TONIGHT AND EARLY TOMORROW.
EXPECTING DEVELOPMENT IN NORTHERN MEXICO WHICH WILL MOVE INTO
SOUTHERN ARIZONA. THUNDERSTORMS WILL HAVE ERRATIC WIND GUSTS TO 40
MPH...LIGHTNING AND LOCALLY HEAVY RAIN WITH REDUCED VISIBILITIES
DOWN TO 2SM FOR A BRIEF PERIOD OF TIME. CLOUD BASES GENERALLY
8-12K FT AGL WITH CEILINGS NEAR 3K FT AGL AROUND THE THUNDERSTORMS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A MOIST ATMOSPHERE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SCATTERED THUNDERSTORMS THROUGH THE WEEKEND. A TROUGH
MOVING TOWARDS THE WEST COAST WILL SHIFT A DRIER WESTERLY FLOW INTO
ARIZONA NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
GWS
WEATHER.GOV/TUCSON
000
FXUS65 KPSR 022119
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
220 PM MST THU JUL 2 2009
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LATEST THINKING REMAINS CONSISTENT FROM THIS MORNING (SEE BELOW).
THUNDERSTORMS HAVE INDEED DEVELOPED ACROSS THE SOUTHWEST DESERTS
AHEAD OF A CYCLONICALLY CURVED VORT LOBE ALONG THE CO RIVER VALLEY.
MODIFIED YUMA SOUNDING GENERATES CAPE ~700 J/KG LIFTING FROM 975 MB
FOR THIS AFTERNOON. STEERING FLOW AROUND THE RIDGE WILL ADVECT THIS
ACTIVITY SLOWLY NORTH AND NORTHEASTWARD...SO ACTIVITY CURRENTLY NEAR
GILA BEND CERTAINLY HAS THE POTENTIAL TO DRIFT TOWARDS THE PHOENIX
METRO AREA EARLY THIS EVENING. STORMS HAVE NOT LOOKED ALL THAT
IMPRESSIVE ON RADAR WITH REGARDS TO SEVERE WINDS/HAIL...THOUGH GUSTY
WINDS IN EXCESS OF 50 MPH ARE POSSIBLE WITH THE STRONGEST CELLS.
WITH PWATS >1.5 INCHES...HEAVY RAIN AND FLOODING MAY TURN OUT TO BE
THE BIGGER THREAT.
CONFIDENCE HAS INCREASED FOR THIS EVENING BASED ON THE 12Z GFS. MCS
IS EXPECTED TO DEVELOP SOUTHEAST OF THE FORECAST AREA...BEFORE
DRIFTING NORTHWARD TONIGHT. MAV POPS HAVE INCREASED AND HIGHLIGHT
THE 06Z-12Z PERIOD AS THE MOST FAVORABLE. ACTIVITY MAY ACTUALLY
CARRY OVER INTO TOMORROW MORNING AND HAVE RAISED POPS CONSIDERABLY
FOR 12Z-18Z FRI. CONSEQUENTLY...LOWER TEMPS ARE EXPECTED WITH HIGH
TEMPS NEAR 100 DEGREES IN PHOENIX.
EXCERPTS FROM MORNING DISCUSSION...
AS WAS THE CASE YESTERDAY...EXTENSIVE CLOUD COVER WILL DELAY THE
ONSET OF CONVECTION THIS AFTERNOON ALONG THE MOGOLLON RIM. ACROSS
THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY CLEAR WITH DEWPOINTS IN
THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST THE ATMOSPHERE WILL BE
UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS THUNDERSTORMS WITHOUT
MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM YUMA TO GILA BEND AND
STRETCHING NORTHWARD INTO THE MOJAVE DESERT...WHERE A VORT LOBE IS
ALREADY PRODUCING MORNING THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
EXTENDED...
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
ONE WEAK IMPULSE HAS MOVED INTO NRN AZ...LEAVING MOSTLY SCT CLOUDS
ABOVE 15 THSD FT ACROSS THE PHOENIX AREA. BUT BY 19Z...TOWERING CU
ACTIVITY WAS UNDERWAY OVER HIGHER TERRAIN OF SOUTHERN AZ AND WILL
LIKELY DEVELOP INTO ISOLATED TSTMS THIS AFTERNOON. WITH A DELAYED
WARMING TREND...CONVECTION IS DELAYED. TSTMS SHOULD FIRE A BIT LATER
THAN USUAL...WITH AN EVENING THREAT...04Z-08Z OF OUTFLOWS IMPACTING
THE SKY HARBOR AREA. EXPECT LIGHT DIURNAL TYPE WINDS THRU FRIDAY.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
CLEAR SKIES SHOULD BECOME SCT CUMULUS WITH ONLY ISOLD TSTMS OVER
HIGHER TERRAIN THRU 03Z. SW WINDS ALOFT ABOVE 20 THSD FT WILL KEEP
SKIES MAINLY CLEAR LATE TONIGHT AND INTO FRIDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...SIPPLE
FIRE WEATHER...VLM
000
FXUS65 KPSR 021913 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1211 PM MST THU JUL 2 2009
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LIGHT PRECIPITATION CONTINUES TO DRIFT NORTHWARD THROUGH
SOUTH-CENTRAL AZ THIS MORNING. AS WAS THE CASE YESTERDAY...EXTENSIVE
CLOUD COVER WILL DELAY THE ONSET OF CONVECTION THIS AFTERNOON ALONG
THE MOGOLLON RIM. ACROSS THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY
CLEAR WITH DEWPOINTS IN THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST
THE ATMOSPHERE WILL BE UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS
THUNDERSTORMS WITHOUT MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM
YUMA TO GILA BEND AND STRETCHING NORTHWARD INTO THE MOJAVE
DESERT...WHERE A VORT LOBE IS ALREADY PRODUCING MORNING
THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
NO SIGNIFICANT CHANGES TO THE FORECAST ARE ANTICIPATED THIS MORNING.
SIMILAR FORECAST IS ON TAP FOR FRIDAY...WITH POPS LOWERED JUST A FEW
PERCENT. HIGH TEMPS SHOULD HOVER AROUND SEASONAL NORMALS EACH
DAY...BUT MAY BE A BIT BELOW SHOULD DEBRIS CLOUDINESS PERSIST WELL
INTO THE DAY.
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
ONE WEAK IMPULSE HAS MOVED INTO NRN AZ...LEAVING MOSTLY SCT CLOUDS
ABOVE 15 THSD FT ACROSS THE PHOENIX AREA. BUT BY 19Z...TOWERING CU
ACTIVITY WAS UNDERWAY OVER HIGHER TERRAIN OF SOUTHERN AZ AND WILL
LIKELY DEVELOP INTO ISOLATED TSTMS THIS AFTERNOON. WITH A DELAYED
WARMING TREND...CONVECTION IS DELAYED. TSTMS SHOULD FIRE A BIT LATER
THAN USUAL...WITH AN EVENING THREAT...04Z-08Z OF OUTFLOWS IMPACTING
THE SKY HARBOR AREA. EXPECT LIGHT DIURNAL TYPE WINDS THRU FRIDAY.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
CLEAR SKIES SHOULD BECOME SCT CUMULUS WITH ONLY ISOLD TSTMS OVER
HIGHER TERRAIN THRU 03Z. SW WINDS ALOFT ABOVE 20 THSD FT WILL KEEP
SKIES MAINLY CLEAR LATE TONIGHT AND INTO FRIDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...SIPPLE
FIRE WEATHER...VLM
000
FXUS65 KFGZ 021640
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
939 AM MST THU JUL 2 2009
.SYNOPSIS...MONSOON FLOW WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO NORTHERN ARIZONA FROM TODAY INTO EARLY NEXT WEEK.
SEASONABLE TEMPERATURES ARE EXPECTED THROUGH THE PERIOD.
&&
.DISCUSSION...MID-LEVEL HIGH PRESSURE CENTERED NEAR NEW MEXICO WILL
CONTINUE TO ALLOW A MOIST MONSOONAL FLOW OVER THE REGION TODAY.
DENSE CLOUD COVER...WITH EMBEDDED LIGHT TO MODERATE SHOWERS...HAS
REMAINED ACROSS MUCH OF THE NORTHLAND OVERNIGHT THROUGH THE CURRENT
TIME THIS MORNING. IN AREAS OF CLEARING...CONVECTION IS LIKELY TO
REDEVELOP RAPIDLY BY THE LATE MORNING AND EARLY AFTERNOON. MORNING
KFGZ SOUNDING AND SHORT-TERM FORECAST MODELS KEEP PRECIPITABLE WATER
VALUES NEAR 1 INCH THROUGH THE DAY...SO THERE WILL BE AMPLE MOISTURE
FOR STORM GENERATION. THE MAIN QUESTION IS IF THERE WILL BE ENOUGH
SUNSHINE AND DAYTIME HEATING FOR STRONGER STORMS TO FORM.
FAVORABLE MOISTURE FOR PRECIPITATION SHOULD REMAIN THROUGH THE END
OF THE WEEK...WITH A DRIER SOUTHWESTERLY FLOW ALOFT DEVELOPING BY
LATE IN THE WEEKEND AND EARLY NEXT WEEK. PRECIP CHANCES ARE LESSER
DURING THIS TIME FRAME...ALTHOUGH SLIGHT CHANCES FOR THUNDERSTORMS
STILL SEEM WARRANTED.
IN ALL...KEEPING NEAR SEASONABLE DAYTIME TEMPERATURES AND PRECIP
CHANCES THROUGH THE MAJORITY OF THE 7-DAY FORECAST.
&&
.AVIATION...FOR THE 18Z PACKAGE...LITTLE CHANGE THE REST OF TODAY
WITH AREAS OF LIGHT RAIN AND ISOLATED THUNDERSTORMS EXPECTED. CIGS
WILL GENERALLY REMAIN AOA 5 KFT AGL AND VIS AOA 6SM IN THE LIGHT
RAIN. ISOLATED HEAVIER DOWNPOURS WILL RESULT IN BRIER PERIODS OF
MVFR CONDITIONS WITH CIGS LOWERING TO AROUND 3 KFT AND VIS 2-4SM.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...HIGH PRESSURE WILL REMAIN EAST OF ARIZONA IN A
FAVORABLE POSITION TO CONTINUE CIRCULATING MOISTURE OVER OUR STATE
THROUGH FRIDAY. ABUNDANT CLOUDS THIS MORNING WILL THIN BY LATE
MORNING. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO
BEGIN BY LATE MORNING AND CONTINUE INTO THE EVENING HOURS. WINDS
WILL GENERALLY BE LIGHT...WITH OUTFLOW-DRIVEN GUSTS FROM 25 TO 45
MPH NEAR THE STRONGER STORMS.
SATURDAY THROUGH MONDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE SATURDAY THROUGH MONDAY AS DRIER AIR MOVES OVER
NORTHERN ARIZONA FROM THE WEST.
&&
PUBLIC..................KD
AVIATION/FIRE WEATHER...PETRO
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER
INFORMATION.
000
FXUS65 KPSR 021635
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
935 AM MST THU JUL 2 2009
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
LIGHT PRECIPITATION CONTINUES TO DRIFT NORTHWARD THROUGH
SOUTH-CENTRAL AZ THIS MORNING. AS WAS THE CASE YESTERDAY...EXTENSIVE
CLOUD COVER WILL DELAY THE ONSET OF CONVECTION THIS AFTERNOON ALONG
THE MOGOLLON RIM. ACROSS THE SOUTHWEST DESERTS...SKIES ARE PRESENTLY
CLEAR WITH DEWPOINTS IN THE MID 60S. LATEST MODEL SOUNDINGS SUGGEST
THE ATMOSPHERE WILL BE UNSTABLE ENOUGH TO PRODUCE ISOLATED AIR MASS
THUNDERSTORMS WITHOUT MUCH OF A DYNAMIC TRIGGER...GENERALLY FROM
YUMA TO GILA BEND AND STRETCHING NORTHWARD INTO THE MOJAVE
DESERT...WHERE A VORT LOBE IS ALREADY PRODUCING MORNING
THUNDERSTORMS ACROSS SOUTHERN NV.
THE OTHER AREA OF INTEREST TODAY WILL BE ACROSS SE AZ. MODELS IN
GOOD AGREEMENT THAT THUNDERSTORMS WILL DEVELOP ACROSS NORTHERN
SONORA LATE THIS AFTERNOON...BEFORE GRADUALLY PROPAGATING NORTHWARD
TOWARDS TUCSON AND EVENTUALLY INTO PINAL COUNTY AND AZZ024. VEERING
FLOW AROUND THE NM ANTICYCLONE WILL MAKE IT DIFFICULT FOR ORGANIZED
ACTIVITY TO REACH THE PHOENIX METRO AREA. NEVERTHELESS...CONDITIONS
WILL BE QUITE UNSTABLE THIS EVENING AND ANY OUTFLOW BOUNDARY MOVING
INTO THIS ENVIRONMENT WILL CERTAINLY HAVE THE POTENTIAL TO GENERATE
ISOLATED STORMS.
NO SIGNIFICANT CHANGES TO THE FORECAST ARE ANTICIPATED THIS MORNING.
SIMILAR FORECAST IS ON TAP FOR FRIDAY...WITH POPS LOWERED JUST A FEW
PERCENT. HIGH TEMPS SHOULD HOVER AROUND SEASONAL NORMALS EACH
DAY...BUT MAY BE A BIT BELOW SHOULD DEBRIS CLOUDINESS PERSIST WELL
INTO THE DAY.
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
THUNDERSTORM ACTIVITY WILL CONTINUE TO DIMINISH THIS MORNING OVER
THE AREA...SOME ACTIVITY WILL CONTINUE OVER THE OPEN DESERTS WEST OF
LUKE AFB UNTIL SUNRISE...WITH LINGERING DEBRIS CLOUDINESS THE REST
OF THE MORNING. EASTERLY WINDS WILL PERSIST AT KPHX/KIWA THROUGH 18Z
...THEN WINDS BECOME WEST-SOUTHWESTERLY INTO THE AFTERNOON HOURS.
THUNDERSTORM POTENTIAL FOR THURSDAY AFTERNOON AND EVENING DOES NOT
LOOK SUBSTANTIALLY BETTER THAN TODAY. HOWEVER...MORE SUNSHINE WILL
HELP REDUCE STABILITY WHICH MAY MAKE IT A BIT EASIER FOR STORMS TO
DEVELOP OVER THE HIGHER TERRAIN NORTH AND EAST OF KPHX/KIWA.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
SOME AREAS OF MID AND HIGH CLOUDINESS WILL SLOWLY DISSIPATE THIS
MORNING. ISOLATED STORM DEVELOPMENT WILL BEGIN THURSDAY AFTERNOON
...CLOSE TO THE MOUNTAINS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH/CB
AVIATION...VLM
FIRE WEATHER...VLM
000
FXUS65 KTWC 021627
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
927 AM MST THU JUL 2 2009
.SYNOPSIS...ABUNDANT MOISTURE WILL BRING SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS ACROSS SOUTHEAST ARIZONA THROUGH INDEPENDENCE
DAY. AS A TROUGH PROGRESSES TO THE WEST COAST...DRIER AIR WILL MOVE
INTO ARIZONA NEXT WEEK FOR A DECREASE IN MOISTURE AND THUNDERSTORM
ACTIVITY.
&&
.DISCUSSION...CLOUD BAND OVER THE CENTRAL PORTION OF THE STATE FROM
NORTH TO SOUTH EXPECTED TO INHIBIT STORM DEVELOP IN THIS AREA THIS
AFTERNOON. BEST LOCATION FOR INITIAL ACTIVITY TO DEVELOP IS COCHISE
COUNTY BECAUSE OF THE SUNSHINE OCCURRING THERE THIS MORNING.
THE LARGER PATTERN OVER THE SOUTHWEST WILL KEEP SCATTERED STORMS IN
THE FORECAST THROUGH THE WEEKEND. THE HIGH CENTERED IN NORTHERN NEW
MEXICO IS KEEPING A WEAK DIVERGENT FLOW ALOFT OVER CENTRAL AND
SOUTHERN ARIZONA. THIS FLOW PATTERN PROVIDES WEAK UPPER VERTICAL
MOTION WHICH IN TURN REINFORCES THE THUNDERSTORM DEVELOPMENT
RESULTING FROM SURFACE HEATING. IN OTHER WORDS...THIS PATTERN IS
SIMILAR TO YESTERDAY ALTHOUGH THE ATMOSPHERE IS SLIGHTLY MORE
UNSTABLE THAN YESTERDAY. NOT MANY CHANGES NEEDED TO THE FORECAST
PACKAGE THIS MORNING.
&&
.AVIATION...MORNING CLOUDINESS WILL GRADUALLY DISSIPATE ALLOWING FOR
SURFACE HEATING TO OCCUR. AFTERNOON AND EVENING SCATTERED TSRA/SHRA
EXPECTED. THUNDERSTORMS WILL HAVE ERRATIC WIND GUSTS TO 40
MPH...LIGHTNING AND LOCALLY HEAVY RAIN WHICH COULD REDUCE
VISIBILITIES TO 2SM. CLOUD BASES GENERALLY 9-12K FT AGL WITH
CEILINGS NEAR 3K FT AGL BY THE THUNDERSTORMS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...A MOIST ATMOSPHERE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
THROUGH THE WEEKEND. A TROUGH MOVING TOWARDS THE WEST COAST WILL
SHIFT A DRIER WESTERLY FLOW INTO ARIZONA NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
GWS
WEATHER.GOV/TUCSON
000
FXUS65 KPSR 021036
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
335 AM MST THU JUL 2 2009
.SYNOPSIS...
A RATHER MOIST MONSOONAL FLOW WILL CONTINUE...AND THE DAILY THREAT
FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
MOIST MONSOONAL FLOW CONTINUES EARLY THIS MORNING ACROSS MOST OF OUR
CWA...AND THE IR/VAPOR IMAGERY NICELY DEPICT THE WHITE PLUME OF DEEP
MOISTURE PUSHING NORTH OUT OF MEXICO AND ACROSS ARIZONA. 500MB HIGH
CENTERED NEAR THE FOUR CORNERS HAS ALLOWED A SLY TO SELY STEERING
FLOW TO SPREAD THIS MOISTURE OVER OUR CWA. WEAK SHORT WAVE EMBEDDED
IN THE PLUME WAS COMBINING WITH BOUNDARY INTERACTIONS TO ALLOW ISOLD
TO SCATTERED SHOWERS AND THUNDERSTORMS TO FORM ACROSS SOUTH-CENTRAL
AND EVEN PARTS OF SOUTHWEST ARIZONA EARLY THIS MORNING. PARTLY BASED
ON SHOWERS/STORMS IN THE AREA AS WELL AS MOIST LOW LEVEL OUTFLOWS...
SURFACE DEWPOINTS ACROSS OUR LOWER DESERTS ARE ALSO RATHER HIGH AT 2
AM...AND WERE RUNNING IN THE UPPER 50S TO UPPER 60S MOST PLACES.
LATEST PROGS ACTUALLY AGREE ON A FEW THINGS THIS MORNING...THE MOST
SIGNIFICANT BEING THAT THE UPPER HIGH WILL SHIFT A BIT TO THE
EAST...AND THE FLOW ALOFT WILL BECOME SWLY WITH TIME TODAY THRU
FRIDAY. SWLY FLOW ALOFT IS NOT VERY FAVORABLE TO BRING STORMS INTO
OUR LOWER DESERTS. NAM/GFS ALSO DO NOT CALL FOR ANY SIGNIFICANT
TRIGGERS/SHORT WAVES TO EXIST IN THE SLY/SWLY FLOW...KEEPING THE
FLOW MORE LAMINAR AND REDUCING POTENTIAL FOR DYNAMICS AND UPPER
FORCING. PROGS ALSO SUGGEST THAT SOME OF THE DEEPER MOISTURE TODAY
WILL FOCUS OVER OUR WESTERN CWA...WITH SOMEWHAT DRIER MORE STABLE
AIR TO EXIST FROM PHOENIX EASTWARD. GIVEN THE POOR STEERING FLOW AND
SOMEWHAT LIMITED INSTABILTY TODAY...WILL CALL FOR JUST A SLIGHT
CHANCE FOR MAINLY AFTERNOON AND EVENING STORMS OVER THE SERN CA AND
LOWER AZ DESERTS...AND KEEP CHANCE POPS CONFINED TO HIGHER TERRAIN
OF ZONE 24. SIMILAR FORECAST IS ON TAP FOR FRIDAY...WITH POPS
LOWERED JUST A FEW PERCENT. HIGH TEMPS SHOULD HOVER AROUND SEASONAL
NORMALS EACH DAY...BUT MAY BE A BIT BELOW SHOULD DEBRIS CLOUDINESS
PERSIST WELL INTO THE DAY.
FOR THE WEEKEND AND INTO THE MIDDLE OF NEXT WEEK...BOTH THE GFS AND
EUROPEAN CONTINUE THEIR FORECAST SCENARIO OF THE PAST SEVERAL MODEL
RUNS...WHICH CALLS FOR A RATHER IMPRESSIVE UPPER TROF TO DEVELOP
ALONG THE WEST COAST BY EARLY NEXT WEEK...GIVING A DRYING SOUTHWEST
TO WEST FLOW ALOFT TO MOST OF OUR CWA. WE WILL SEE A GRADUAL
DECREASE IN MOISTURE FROM THE WEST EACH DAY...BY SATURDAY POPS WILL
DROP INTO THE SINGLE DIGITS OVER SERN CA WITH SLIGHT CHANCE EXPECTED
OVER THE LOWER AZ DESERTS AND CHANCE POPS EAST OF GLOBE. BY MONDAY
SUFFICIENT MOISTURE WILL BE SCOURED OUT TO ELIMINATE THE CHANCE FOR
STORMS OVER OUR LOWER DESERTS...WITH JUST A SLIGHT CHANCE FOR
AFTN/EVE STORMS CONFINDED TO THE HIGHER TERRAIN EAST OF PHOENIX.
AS DRYING OCCURS...EXPECT HIGH TEMPS TO RISE AND CLIMB TO ABOVE
NORMAL VALUES...ESPECIALLY OUT WEST WHERE HIGHS AROUND 110 ARE
POSSIBLE OVER THE WEEKEND ACROSS THE HOTTER DESERTS. AS THE UPPER
TROF SHIFTS SLIGHTLY INLAND AND HEIGHTS FALL...TEMPS WILL DROP BACK
OFF OVER THE WESTERN CWA DURING THE EARLY TO MID PART OF NEXT WEEK.
FOR TUESDAY INTO WEDNESDAY...UPPER TROF SHARPENS UP A BIT AND FLOW
BACKS SOMEWHAT. THIS WILL ALLOW MOISTURE TO BE DRAWN WESTWARD SO
THAT A SLIGHT CHANCE FOR THUNDERSTORMS WILL REDEVELOP OVER THE
SOUTH-CENTRAL DESERTS EACH DAY. STILL...POPS WILL BE LOW AND ONLY
AROUND 10-15 PERCENT.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...
THUNDERSTORM ACTIVITY WILL CONTINUE TO DIMINISH THIS MORNING OVER
THE AREA...SOME ACTIVITY WILL CONTINUE OVER THE OPEN DESERTS WEST OF
LUKE AFB UNTIL SUNRISE...WITH LINGERING DEBRIS CLOUDINESS THE REST
OF THE MORNING. EASTERLY WINDS WILL PERSIST AT KPHX/KIWA THROUGH 18Z
...THEN WINDS BECOME WEST-SOUTHWESTERLY INTO THE AFTERNOON HOURS.
THUNDERSTORM POTENTIAL FOR THURSDAY AFTERNOON AND EVENING DOES NOT
LOOK SUBSTANTIALLY BETTER THAN TODAY. HOWEVER...MORE SUNSHINE WILL
HELP REDUCE STABILITY WHICH MAY MAKE IT A BIT EASIER FOR STORMS TO
DEVELOP OVER THE HIGHER TERRAIN NORTH AND EAST OF KPHX/KIWA.
KIPL/KBLH AND SURROUNDING AIRFIELDS...
SOME AREAS OF MID AND HIGH CLOUDINESS WILL SLOWLY DISSIPATE THIS
MORNING. ISOLATED STORM DEVELOPMENT WILL BEGIN THURSDAY AFTERNOON
...CLOSE TO THE MOUNTAINS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...AS
WELL AS A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...CB
AVIATION...VLM
FIRE WEATHER...VLM
000
FXUS65 KFGZ 020947
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
230 AM MST THU JUL 2 2009
.SYNOPSIS...MONSOON FLOW WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO NORTHERN ARIZONA FROM TODAY INTO EARLY NEXT WEEK.
SEASONABLE TEMPERATURES ARE EXPECTED THROUGH THE PERIOD.
&&
.DISCUSSION...HIGH PRESSURE IN THE MID LEVELS WAS CENTERED OVER NEW
MEXICO THIS MORNING. MOISTURE AND AMPLE CLOUDS WERE STREAMING
NORTHWARD AROUND THE WESTERN EDGE OF THIS HIGH. ISOLATED SHOWERS
WERE LOCATED ACROSS NORTHERN ARIZONA DURING THE MORNING HOURS BUT
GRADUALLY DECREASING. FOR TODAY...IT APPEARS THE MID LEVEL CLOUD
LAYER WILL BE FAIRLY PERSISTENT...MODELS SUPPORT THIS AS WELL. IF
THIS IS THE CASE THEN EXPECT ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS THE AREA BUT FEW STRONG THUNDERSTORMS. THERE
JUST WON`T BE ENOUGH SUNSHINE TO FUEL STRONGER STORMS.
OTHERWISE...LIGHT WINDS AND SEASONABLE TEMPERATURES APPEAR IN ORDER.
FOR FRIDAY AND THE WEEKEND...THE MID LEVEL HIGH WILL CONTINUE TO
SHIFT EASTWARD WITH WESTERLY FLOW BECOMING MORE PROMINENT ALOFT.
STILL THINK FRIDAY WILL BE REASONABLY ACTIVE WITH BOUNDARY LAYER
MOISTURE REMAINING INTACT AND DAYTIME HEATING ENOUGH TO OVERCOME ANY
MID LEVEL WARMING. BUT BY SATURDAY AND HEADING INTO EARLY NEXT
WEEK...THE SOUTHWEST FLOW ALOFT WILL LIKELY ADVECT IN A MID-LEVEL
WARM CAP. THIS SHOULD RESULT IN DECREASING THUNDERSTORM ACTIVITY.
HOWEVER...DEEP MOISTURE WILL RESIDE JUST TO THE SOUTH AND THINK
BOUNDARY LAYER MOISTURE WILL REMAIN PERSISTENT ENOUGH TO WARRANT THE
CONTINUATION OF AT LEAST A SLIGHT CHANCE OF SHOWERS AND STORMS INTO
NEXT WEEK.
&&
.AVIATION...FOR THE 12Z PACKAGE...AREAS OF LIGHT RAIN...AND
ISOLATED THUNDERSTORMS...WITH CLOUD BASES 7-9 KFT AGL WILL PERSIST
OVER MUCH OF NORTHERN ARIZONA THROUGH 15Z. SOME CLEARING IS EXPECTED
15-18Z BEFORE SHOWERS AND THUNDERSTORMS BEGIN DEVELOPING AGAIN AFTER
18Z OVER NORTHERN ARIZONA. AVIATION DISCUSSION NOT UPDATED FOR
AMENDMENTS.
&&
.FIRE WEATHER...HIGH PRESSURE WILL REMAIN EAST OF ARIZONA IN A
FAVORABLE POSITION TO CONTINUE CIRCULATING MOISTURE OVER OUR STATE
THROUGH FRIDAY. ABUNDANT CLOUDS THIS MORNING WILL THIN BY LATE
MORNING. ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED TO
BEGIN BY LATE MORNING AND CONTINUE INTO THE EVENING HOURS. WINDS
WILL GENERALLY BE LIGHT...WITH OUTFLOW-DRIVEN GUSTS FROM 25 TO 45
MPH NEAR THE STRONGER STORMS.
SATURDAY THROUGH MONDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE SATURDAY THROUGH MONDAY AS DRIER AIR MOVES OVER
NORTHERN ARIZONA FROM THE WEST.
&&
PUBLIC..................MCCOLLUM
AVIATION/FIRE WEATHER...MAS
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER
INFORMATION.
000
FXUS65 KTWC 020905
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
205 AM MST THU JUL 2 2009
.SYNOPSIS...AMPLE MOISTURE WILL BRING SCATTERED MAINLY AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST ARIZONA THROUGH
INDEPENDENCE DAY. SOMEWHAT DRIER CONDITIONS EARLY NEXT WEEK ALTHOUGH
STILL ENOUGH MOISTURE FOR A SLIGHT CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS.
&&
.DISCUSSION...HIGH PRESSURE ALOFT CENTERED OVER NEW MEXICO TO MOVE
EWD AND BECOME POSITIONED OVER THE SRN CONUS PLAINS BY LATE SAT.
AMPLE MOISTURE IN COMBINATION WITH SLY/SELY MID-LEVEL FLOW WILL
JUSTIFY A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS PARTICULARLY FROM THE TUCSON METRO AREA EWD THRU SAT.
THEREAFTER...02/00Z GFS/ECMWF WERE FAIRLY SIMILAR WITH REGARD TO
DEPICTING TROUGH OVER THE PACIFIC NW AND RIDGE OVER THE CENTRAL
CONUS PLAINS EARLY NEXT WEEK. SOMEWHAT DRIER CONDITIONS PROGGED
ACROSS THIS FORECAST AREA THOUGH MORE PRONOUNCED DRYING OVER NRN/WRN
AZ. PER COORD WITH NEIGHBORING WFO/S WILL OPT FOR JUST A SLIGHT
CHANCE OF MAINLY AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS MOST
SECTIONS NEXT MON-WED...WITH PRECIP-FREE CONDITIONS ACROSS FAR WRN
PIMA COUNTY. NEAR NORMAL DAYTIME HIGH TEMPS TO OCCUR THIS HOLIDAY
WEEKEND AND EARLY NEXT WEEK.
&&
.AVIATION...CONVECTIVE DEBRIS CLOUDINESS MOSTLY AT OR ABOVE 12K FT
AGL EXPECTED TO GRADUALLY DISSIPATE THROUGH THE MORNING HOURS.
THEREAFTER...SCATTERED TSRA/SHRA IS FORECAST TO OCCUR DURING THE
18Z-06Z PERIOD. CLOUD BASES TO GENERALLY BE 9-12K FT AGL THOUGH
CEILINGS AROUND 3-5K FT AGL NEAR TSRA/SHRA. DIURNALLY DRIVEN SURFACE
WINDS GENERALLY LESS THAN 12 KTS INTO FRIDAY THOUGH GUSTY AND
ERRATIC SURFACE WINDS NEAR TSRA. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...A MOIST ATMOSPHERE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS THROUGH INDEPENDENCE DAY. THE FAIRLY HIGH HUMIDITY
AND RAINFALL WILL RESULT IN FEW FIRE WEATHER CONCERNS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
BF
WEATHER.GOV/TUCSON
000
FXUS65 KPSR 020554 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1050 PM MST WED JUL 1 2009
.UPDATE...
UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED OVER
SOUTH-CENTRAL ARIZONA THIS EVENING BEFORE TAPERING OFF AFTER
MIDNIGHT. THE DAILY THREAT FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THE WORK WEEK...ALONG WITH HIGH
TEMPERATURES A FEW DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. LATE
IN THE WEEKEND AND INTO EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW
WILL CONFINE SHOWERS AND THUNDERSTORMS TO PRIMARILY THE HIGHER
TERRAIN NORTH AND EAST OF THE PHOENIX AREA...WHILE ALLOWING HIGH
TEMPERATURES TO RETURN TO NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
CONVECTION HAS NOT MATERIALIZED OVER MUCH OF THE FORECAST AREA THIS
EVENING BUT ISOLATED STORM ACTIVITY OVER PINAL COUNTY AND OUTFLOWS
ELSEWHERE INCLUDING THE PHOENIX AREA ARE STILL GOING ON AS OF THIS
WRITING. THE UPPER LEVEL DISTURBANCE PROGGED BY THE MODELS DOES NOT
APPEAR TO BE A FACTOR...WOULD HAVE EXPECTED STORM ACTIVITY TO BE
LONGER LIVED AND MORE WIDESPREAD OVER SOUTHERN ARIZONA BY NOW. 00Z
AND 03Z PSR SOUNDING SHOWS A MODEST AMOUNT OF CAPE COUNTERED BY A
FAIR AMOUNT OF CONVECTIVE INHIBITION. A STRONG OUTFLOW ENTERING THE
SOUTHEAST PHOENIX AREA MAY LEAD TO SOME ISOLATED SHORT LIVED STORMS
BUT THAT WOULD BE ABOUT IT. WILL NEED TO MAKE SOME UPDATES TO THE
FORECAST TO REMOVE POPS FROM SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA FOR TONIGHT.
FOR THURSDAY...BOTH NAM AND GFS INDICATE THAT THE DEEPEST MOISTURE
FOR OUR FORECAST AREA WILL BE OVER SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...THOUGH THE GFS IS A BIT MORE GENEROUS WITH THE MOISTURE
OVER SOUTH-CENTRAL ARIZONA. THEY ALSO SHOW SOUTH-SOUTHWEST STEERING
FLOW WHICH IS NOT AN IDEAL DIRECTION FOR LOWER ELEVATION STORM
ACTIVITY. GFS INDICATES ANOTHER PERTURBATION MOVING THROUGH TOMORROW
EVENING...BUT NOT THOSE FEATURES ARE NOT MODELED WELL ENOUGH TO
COUNT ON. IN SHORT NO MAJOR CHANGES FOR TOMORROW IN THE KINEMATICS
BUT THERE SHOULD BE LESS CLOUD COVER SO THERE SHOULD BE MORE SURFACE
HEATING WHICH SHOULD HELP REDUCE SOME OF THE CONVECTIVE INHIBITION.
PREVIOUS DISCUSSION...
AS OF 2PM...SAT TRENDS ARE ENCOURAGING...SHOWING CLEARING OVER THE
S-CNTRL AZ DESERTS THIS PAST HOUR OR SO. DOWN OVER SOUTHEAST
AZ...WHERE THEY STARTED WITH LESS CLOUDS THAN THE CENTRAL
DESERTS...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
UNDERWAY. THE RIM IS ALSO STARTING TO FILL IN A BIT...AND WE CAN SEE
CU BUILDING OUT THE WINDOW TO THE SOUTH...AS WELL AS OVER PORTIONS
OF THE NORTHWEST VALLEY.
THE STEERING FLOW REMAINS FAVORABLE...EAST/SOUTHEASTERLY FROM
700-500MB AT 15-20KT. MODIFYING THE /FAIRLY CONTAMINATED/ 12Z PSR
SOUNDING FROM THIS MORNING...AND USING A FORECAST HIGH OF 100 WITH A
MIXING RATIO OF 10.5 G/KG...THE MEAN TEMP METHODOLOGY YIELDS ABOUT
520 J/KG OF CAPE...WITH A SLIVER OF CONVECTIVE INHIBITION. SHOULD
NOT TAKE MUCH TO OVERCOME THE NEG ENERGY-- A GOOD OUTFLOW PUSH FROM
THE EAST OR SOUTHEAST...ALONG WITH A BIT OF COOL ADVECTION IN THE
MID LEVELS FROM THE HIGHER TERRAIN STORMS MIGHT BE ALL IT TAKES TO
GET THINGS GOING IN THE SOUTH-CENTRAL DESERTS EASTWARD.
OUT WEST WHERE A WEAK LINE OF SHOWERS AND THUNDERSTORMS SLOWLY MOVED
NORTHWESTWARD THROUGH THE CWA EARLIER TODAY...THE CLOUDS ARE HANGING
IN THERE...AND KBLH TEMP IS DOWN 13 DEG FROM THIS TIME YESTERDAY.
THAT SAID...WE CANNOT EXPECT THE THERMAL DYNAMICS ALONE TO GET
THINGS GOING OUT THAT WAY...AND WILL NEED TO RELY ON A GREATER DEAL
OF LIFT/SUPPORT ALOFT. NAM AND RUC ARE BOTH SHOWING A DECENT AREA OF
UPPER LEVEL DIVERGENCE ROTATING AROUND THE WESTERN EDGE OF THE HIGH.
THIS AREA OF UPPER LEVEL SUPPORT IS PROGGED TO MOVED NORTHWARD
THROUGH W-CNTRL ARIZONA LATER THIS EVENING AND OVERNIGHT...AND
SHOULD HELP TO OVERCOME THE LACK OF SURFACE HEATING OVER THE WESTERN
DESERTS. AS SUCH...THE FORECAST CALLS FOR SCATTERED SHOWERS AND
THUNDERSTORMS PRETTY MUCH FROM OUR WESTERN CWA BOUNDARY EASTWARD
THROUGH SOUTHERN GILA COUNTY THIS AFTERNOON AND EVENING.
THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF PRODUCING STRONG AND
GUSTY OUTFLOW WINDS IN EXCESS OF 40 MPH...WITH PERIODS OF BRIEF
HEAVY RAIN. BUT IN TERMS OF SEVERE...TEMPS/TD PROFILE DOES NOT
REALLY SUPPORT IT.
TOMORROW THROUGH THE END OF THE WORK WEEK...THE MOISTURE WILL HANG
AROUND...FOR A CONTINUED THREAT OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY...FAVORING THE HIGHER TERRAIN...WITH DESERT
HIGH TEMPS RUNNING A FEW DEG BELOW NORMAL. DIFFICULT TO SAY WITH
MUCH CERTAINTY WHAT THE WEATHER WILL BE 12 HOURS OUT THIS TIME OF
YEAR...AND GOING BEYOND DAY 2 REALLY IS BEST LEFT TO CLIMO.
LATE IN THE WEEKEND AND NEXT WEEK...MODELS CONTINUE TO SHOW A DRIER
WEST/SOUTHWESTERLY FLOW OVER THE REGION...CONFINING THE THREAT FOR
DAILY SHOWERS ANDS THUNDERSTORMS TO THE HIGHER TERRAIN...WHILE
ALLOWING DESERT HIGHS TO WARM BACK TO NEAR NORMAL FOR EARLY JULY.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...THUNDERSTORMS HAVE DIMINISHED
SIGNIFICANTLY AS OF LATE THIS EVENING WITH ISOLATED LIGHT SHOWERS
OVER NORTHERN PINAL COUNTY. OUTFLOW FROM DISTANT THUNDERSTORMS WILL
KEEP AN EASTERLY WIND DIRECTION AT THE TAF SITES THE REST OF THE
NIGHT. STORM PROBABILITY AT THE TAF SITES IS TOO LOW TO INSERT TEMPO
GROUPS FOR THUNDERSTORMS. HOWEVER...INSERTED VCSH IN ACKNOWLEDGEMENT
OF THE PRESENCE OF THE LIGHT SHOWERS. EXPECT THESE TO DISSIPATE
OVERNIGHT WITH JUST SOME LINGERING DEBRIS CLOUDINESS. STORM
POTENTIAL FOR THURSDAY AFTERNOON AND EVENING DOES NOT LOOK
SUBSTANTIALLY BETTER THAN TODAY. HOWEVER...MORE SUNSHINE WILL HELP
REDUCE STABILITY WHICH MAY MAKE IT A BIT EASIER FOR STORMS TO
DEVELOP.
KIPL/KBLH AND SURROUNDING AIRFIELDS...SOME AREAS OF MID AND HIGH
CLOUDINESS WILL SLOWLY DISSIPATE OVERNIGHT. NO STORM ACTIVITY IS
ANTICIPATED OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA THE REST
OF THE NIGHT BEFORE ISOLATED DEVELOPMENT BEGINS THURSDAY
AFTERNOON...CLOSE TO THE MOUNTAINS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOISTURE WILL BE SLOWLY DECREASING DURING THE PERIOD UNDER A
SOUTHWEST FLOW ALOFT. THERE WILL BE ENOUGH HUMIDITY FOR SLIGHT
CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS MAINLY OVER THE
HIGHER TERRAIN. SUNSHINE WILL DOMINATE THE LOWER DESERTS WITH
TEMPERATURES NEAR NORMAL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...AJ
FIRE WEATHER...SIPPLE
000
FXUS65 KPSR 020452
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
950 PM MST WED JUL 1 2009
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED OVER
SOUTH-CENTRAL ARIZONA THIS EVENING BEFORE TAPERING OFF AFTER
MIDNIGHT. THE DAILY THREAT FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THE WORK WEEK...ALONG WITH HIGH
TEMPERATURES A FEW DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. LATE
IN THE WEEKEND AND INTO EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW
WILL CONFINE SHOWERS AND THUNDERSTORMS TO PRIMARILY THE HIGHER
TERRAIN NORTH AND EAST OF THE PHOENIX AREA...WHILE ALLOWING HIGH
TEMPERATURES TO RETURN TO NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
CONVECTION HAS NOT MATERIALIZED OVER MUCH OF THE FORECAST AREA THIS
EVENING BUT ISOLATED STORM ACTIVITY OVER PINAL COUNTY AND OUTFLOWS
ELSEWHERE INCLUDING THE PHOENIX AREA ARE STILL GOING ON AS OF THIS
WRITING. THE UPPER LEVEL DISTURBANCE PROGGED BY THE MODELS DOES NOT
APPEAR TO BE A FACTOR...WOULD HAVE EXPECTED STORM ACTIVITY TO BE
LONGER LIVED AND MORE WIDESPREAD OVER SOUTHERN ARIZONA BY NOW. 00Z
AND 03Z PSR SOUNDING SHOWS A MODEST AMOUNT OF CAPE COUNTERED BY A
FAIR AMOUNT OF CONVECTIVE INHIBITION. A STRONG OUTFLOW ENTERING THE
SOUTHEAST PHOENIX AREA MAY LEAD TO SOME ISOLATED SHORT LIVED STORMS
BUT THAT WOULD BE ABOUT IT. WILL NEED TO MAKE SOME UPDATES TO THE
FORECAST TO REMOVE POPS FROM SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA FOR TONIGHT.
FOR THURSDAY...BOTH NAM AND GFS INDICATE THAT THE DEEPEST MOISTURE
FOR OUR FORECAST AREA WILL BE OVER SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA...THOUGH THE GFS IS A BIT MORE GENEROUS WITH THE MOISTURE
OVER SOUTH-CENTRAL ARIZONA. THEY ALSO SHOW SOUTH-SOUTHWEST STEERING
FLOW WHICH IS NOT AN IDEAL DIRECTION FOR LOWER ELEVATION STORM
ACTIVITY. GFS INDICATES ANOTHER PERTURBATION MOVING THROUGH TOMORROW
EVENING...BUT NOT THOSE FEATURES ARE NOT MODELED WELL ENOUGH TO
COUNT ON. IN SHORT NO MAJOR CHANGES FOR TOMORROW IN THE KINEMATICS
BUT THERE SHOULD BE LESS CLOUD COVER SO THERE SHOULD BE MORE SURFACE
HEATING WHICH SHOULD HELP REDUCE SOME OF THE CONVECTIVE INHIBITION.
PREVIOUS DISCUSSION...
AS OF 2PM...SAT TRENDS ARE ENCOURAGING...SHOWING CLEARING OVER THE
S-CNTRL AZ DESERTS THIS PAST HOUR OR SO. DOWN OVER SOUTHEAST
AZ...WHERE THEY STARTED WITH LESS CLOUDS THAN THE CENTRAL
DESERTS...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
UNDERWAY. THE RIM IS ALSO STARTING TO FILL IN A BIT...AND WE CAN SEE
CU BUILDING OUT THE WINDOW TO THE SOUTH...AS WELL AS OVER PORTIONS
OF THE NORTHWEST VALLEY.
THE STEERING FLOW REMAINS FAVORABLE...EAST/SOUTHEASTERLY FROM
700-500MB AT 15-20KT. MODIFYING THE /FAIRLY CONTAMINATED/ 12Z PSR
SOUNDING FROM THIS MORNING...AND USING A FORECAST HIGH OF 100 WITH A
MIXING RATIO OF 10.5 G/KG...THE MEAN TEMP METHODOLOGY YIELDS ABOUT
520 J/KG OF CAPE...WITH A SLIVER OF CONVECTIVE INHIBITION. SHOULD
NOT TAKE MUCH TO OVERCOME THE NEG ENERGY-- A GOOD OUTFLOW PUSH FROM
THE EAST OR SOUTHEAST...ALONG WITH A BIT OF COOL ADVECTION IN THE
MID LEVELS FROM THE HIGHER TERRAIN STORMS MIGHT BE ALL IT TAKES TO
GET THINGS GOING IN THE SOUTH-CENTRAL DESERTS EASTWARD.
OUT WEST WHERE A WEAK LINE OF SHOWERS AND THUNDERSTORMS SLOWLY MOVED
NORTHWESTWARD THROUGH THE CWA EARLIER TODAY...THE CLOUDS ARE HANGING
IN THERE...AND KBLH TEMP IS DOWN 13 DEG FROM THIS TIME YESTERDAY.
THAT SAID...WE CANNOT EXPECT THE THERMAL DYNAMICS ALONE TO GET
THINGS GOING OUT THAT WAY...AND WILL NEED TO RELY ON A GREATER DEAL
OF LIFT/SUPPORT ALOFT. NAM AND RUC ARE BOTH SHOWING A DECENT AREA OF
UPPER LEVEL DIVERGENCE ROTATING AROUND THE WESTERN EDGE OF THE HIGH.
THIS AREA OF UPPER LEVEL SUPPORT IS PROGGED TO MOVED NORTHWARD
THROUGH W-CNTRL ARIZONA LATER THIS EVENING AND OVERNIGHT...AND
SHOULD HELP TO OVERCOME THE LACK OF SURFACE HEATING OVER THE WESTERN
DESERTS. AS SUCH...THE FORECAST CALLS FOR SCATTERED SHOWERS AND
THUNDERSTORMS PRETTY MUCH FROM OUR WESTERN CWA BOUNDARY EASTWARD
THROUGH SOUTHERN GILA COUNTY THIS AFTERNOON AND EVENING.
THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF PRODUCING STRONG AND
GUSTY OUTFLOW WINDS IN EXCESS OF 40 MPH...WITH PERIODS OF BRIEF
HEAVY RAIN. BUT IN TERMS OF SEVERE...TEMPS/TD PROFILE DOES NOT
REALLY SUPPORT IT.
TOMORROW THROUGH THE END OF THE WORK WEEK...THE MOISTURE WILL HANG
AROUND...FOR A CONTINUED THREAT OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY...FAVORING THE HIGHER TERRAIN...WITH DESERT
HIGH TEMPS RUNNING A FEW DEG BELOW NORMAL. DIFFICULT TO SAY WITH
MUCH CERTAINTY WHAT THE WEATHER WILL BE 12 HOURS OUT THIS TIME OF
YEAR...AND GOING BEYOND DAY 2 REALLY IS BEST LEFT TO CLIMO.
LATE IN THE WEEKEND AND NEXT WEEK...MODELS CONTINUE TO SHOW A DRIER
WEST/SOUTHWESTERLY FLOW OVER THE REGION...CONFINING THE THREAT FOR
DAILY SHOWERS ANDS THUNDERSTORMS TO THE HIGHER TERRAIN...WHILE
ALLOWING DESERT HIGHS TO WARM BACK TO NEAR NORMAL FOR EARLY JULY.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...CLOUDINESS FROM EARLIER TODAY
HAS THINNED OUT. THIS SHOULD AID IN THE DEVELOPMENT OF INSTABILITY
BUT STORMS HAVE BEEN SLOW TO DEVELOP ON THE LOWER ELEVATIONS. WILL
BE WATCHING STORM ACTIVITY OVER SOUTHEAST ARIZONA AND THE RIM
COUNTRY TO PRODUCE OUTFLOWS WHICH MAY PROVIDE NECESSARY LIFT TO
TRIGGER STORMS OVER THE PHOENIX AREA. WITHOUT THAT...WILL NEED
DYNAMICAL HELP FROM A DISTURBANCE PROGGED TO MOVE NORTHWARD ACROSS
ARIZONA TONIGHT. THIS DISTURBANCE IS NOT READILY EVIDENT IN THE
WATER VAPOR IMAGERY THOUGH. HOWEVER...LOCATION OF MOST ACTIVE
CONVECTION IN SOUTHEAST ARIZONA CORRESPONDS WELL WITH WHERE THIS
FEATURE SHOULD BE. DUE TO THE MEAGER LATE AFTERNOON CONVECTIVE
ACTIVITY...HAVE HELD OFF ON PUTTING IN TEMPO GROUPS FOR
THUNDERSTORMS AND STRONG WINDS IN THE TAFS. BUT POTENTIAL IS STILL
THERE SO AMMENDMENTS WILL QUITE POSSIBLY BE NECESSARY.
KIPL/KBLH AND SURROUNDING AIRFIELDS...DEBRIS CLOUDINESS HAS
CONTINUED TO HOLD ON FROM NEAR THE LOWER COLORADO RIVER VALLEY
WESTWARD. THIS HAS LIKELY INHIBITED INSTABILITY. WITH HIGH DEW
POINTS...AND MODEST AIR TEMPERATURES...ANY STORMS THAT DO DEVELP
WILL BE MORE LIKELY TO PRODUCE BRIEF HEAVY RAIN THAN VERY STRONG
WINDS. CLOUD BASES WOULD LIKELY BE WELL BELOW 10 KFT. DUE TO THE
ABUNDANT MOISTURE...STORM ACTIVITY CANT BE RULED OUT...BUT THIS AREA
SEEMS LESS LIKELY TO BENEFIT FROM THE UPPER DISTURBANCE ADVERTISED
TO MOVE THROUGH ARIZONA. THUS HAVE HELD OFF ON TEMPO GROUPS FOR
THUNDERSTORMS. BUT DUE TO MOISTURE AVAILABILITY...STORM POTENTIAL IS
STILL THERE SO AMMENDMENTS MAY VERY WELL BE NECESSARY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOISTURE WILL BE SLOWLY DECREASING DURING THE PERIOD UNDER A
SOUTHWEST FLOW ALOFT. THERE WILL BE ENOUGH HUMIDITY FOR SLIGHT
CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS MAINLY OVER THE
HIGHER TERRAIN. SUNSHINE WILL DOMINATE THE LOWER DESERTS WITH
TEMPERATURES NEAR NORMAL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...AJ/WANEK
AVIATION...AJ
FIRE WEATHER...SIPPLE
000
FXUS65 KTWC 020437
AFDTWC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
925 PM MST WED JUL 1 2009
.SYNOPSIS...THE CURRENT WEATHER PATTERN WILL RESULT IN SCATTERED
MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS THROUGH
FRIDAY. DRIER AIR WILL THEN TRY TO PUSH IN FROM THE WEST THIS
WEEKEND AS HIGH PRESSURE ALOFT SLOWLY PUSHES EAST. ALTHOUGH THIS
WILL REDUCE THE COVERAGE OF STORMS ACROSS SOUTHEAST ARIZONA...THE
POSSIBILITY OF STRONGER THUNDERSTORMS INCREASES.
&&
.DISCUSSION...DEEP MOISTURE HAS BECOME ENTRENCHED OVER SOUTHEAST
ARIZONA. GOES BLENDED PWAT VALUES NOW RANGE FROM 1.50-2.00 INCHES
OVER THE SOUTHERN HALF OF ARIZONA. THIS MOISTURE PROFILE IS MORE
INDICATIVE OF THE MIDDLE OF THE MONSOON INSTEAD OF THE EARLY STAGES.
CONVECTIVE ACTIVITY WAS WEAKER WITH LESS COVERAGE THIS AFTERNOON
VERSUS THE PAST COUPLE OF DAYS. TUESDAY MORNING CONVECTION AND
DEBRIS CLOUDINESS LIMITED SURFACE HEATING AND ALSO PROVIDED
MID-LEVEL WARMING...WHICH SHOWS UP NICELY IN THE FORM OF POOR
MID-LEVEL LAPSE RATES ON THE 00Z TUS SOUNDING. THE STORMS THAT DID
DEVELOP PRODUCED HEAVY RAINS...MAINLY OVER CENTRAL PIMA COUNTY WHERE
GAUGES WEST OF ARIVACA SHOWED VALUES FROM 1.50-2.00 INCHES.
LARGE CONVECTIVE COMPLEX CURRENTLY COVERING ALL OF SONORA. SOUTHERLY
FLOW ABOVE 12000 FEET IS BRINGING MID-LEVEL STRATIFORM MOISTURE
NORTHWARD INTO THE AREA FROM THIS COMPLEX. HAVE UPPED POPS 20-30 PCT
FOR AREAS EAST OF SELLS TO ACCOUNT FOR THIS MOISTURE. MOST OF THE
PRECIP WILL BE LIGHT WITH VALUES LESS THAN .10 INCHES...BUT ACTIVITY
COULD LINGER THROUGH THE NIGHT. ALSO UPPED CLOUD COVER TO
CLOUDY-MOSTLY CLOUDY OVER MUCH OF THE AREA THROUGH THURSDAY MORNING.
MUCH UNCERTAINTY WITH THURSDAY CONVECTION AS DEBRIS CLOUDINESS MAY
PERSIST THROUGH MUCH OF THE DAY AND LAPSE RATES WILL AGAIN BE LESS
THAN OPTIMAL. ALTHOUGH...WITH DEEP MOISTURE IN PLACE IT WON`T TAKE
MUCH LIFT TO GENERATE CONVECTION.
&&
.AVIATION...SCATTERED AREAS OF GENERALLY LIGHT STRATIFORM
PRECIPITATION IS OCCURRING OVER AREAS EAST OF SELLS. AS THE EVENING
PROGRESSES THE CIGS WILL GENERALLY BE AROUND 8-10K FT OVER MOST OF
THE FORECAST AREA...BUT THESE CIGS WILL ERODE AND BECOME SCATTERED
TO OCCASIONALLY BROKEN TOWARDS MORNING. EXPECTING ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS AGAIN THURSDAY AFTERNOON. GENERALLY
SCATTERED CUMULUS IN THE LATE MORNING AND EARLY AFTERNOON ON
THURSDAY WITH BROKEN CIGS DURING THE MID TO LATE AFTERNOON. SURFACE
WINDS GENERALLY DIURNAL IN NATURE AND LESS THAN 15 KTS...WITH THE
EXCEPTION OF ERRATIC/GUSTY OUTFLOW WINDS NEAR ANY THUNDERSTORMS
THURSDAY AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...A MOIST ATMOSPHERE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS THIS WEEK. THE HIGHER HUMIDITY AND RAINFALL WILL
RESULT IN FEW FIRE WEATHER CONCERNS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
$$
SHOEMAKER
WEATHER.GOV/TUCSON
000
FXUS65 KFGZ 020408
AFDFGZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 PM MST WED JUL 1 2009
.SYNOPSIS...MONSOON FLOW WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TO NORTHERN ARIZONA FROM NOW INTO THE WEEKEND.
SEASONABLE TEMPERATURES ARE EXPECTED THROUGH THE PERIOD.
&&
.DISCUSSION...MOISTURE SURGED NORTHWARD LAST NIGHT AS A RESULT OF
STORM OUTFLOWS AND THE GENERAL SHIFTING OF THE LARGE SCALE FLOW.
THUNDERSTORMS DEVELOPED MUCH FURTHER NORTH THAN ON TUESDAY...WITH
THE STRONGEST STORMS NEAR THE SAN FRANCISCO PEAKS...NORTHERN GILA
COUNTY...AND LATE THIS EVENING OVER MUCH OF CENTRAL YAVAPAI COUNTY.
AT 845 PM...A LARGE SCALE THUNDERSTORM OUTFLOW WAS PUSHING
SOUTHWESTWARD THROUGH CENTRAL YAVAPAI COUNTY INCLUDING PRESCOTT AND
VICINITY...WITH SHOWERS AND THUNDERSTORMS DEVELOPING ALONG AND
BEHIND THIS BOUNDARY. SOME HEAVY RAIN WILL BE POSSIBLE IN THE
PRESCOTT AREA FOR THE NEXT COUPLE HOURS...THEN THE THREAT SHIFTS
SOUTHWEST OF THERE. ELSEWHERE FOR THE REST OF TONIGHT...MAINLY JUST
A FEW SHOWERS POSSIBLE.
FAVORABLE MOISTURE FOR PRECIPITATION SHOULD REMAIN THROUGH THE END
OF THE WEEK...WITH A DRIER WESTERLY FLOW ALOFT DEVELOPING BY LATE IN
THE WEEKEND AND EARLY NEXT WEEK. PRECIP CHANCES ARE REDUCED FOR THIS
TIME FRAME...ALTHOUGH NOT ELIMINATED.
IN ALL...KEEPING NEAR SEASONABLE DAYTIME TEMPERATURES AND PRECIP
CHANCES THROUGH THE MAJORITY OF THE 7-DAY FORECAST.
&&
.AVIATION...FOR THE 06Z PACKAGE...AREAS OF LIGHT RAIN WITH CLOUD
BASES NEAR 8 KFT AGL WILL PERSIST OVER MUCH OF COCONINO...SOUTHERN
NAVAJO AND GILA COUNTIES THROUGH 07Z. FURTHER SOUTH...SCATTERED
THUNDERSTORMS WILL CONTINUE ACROSS PORTIONS OF YAVAPAI COUNTY
THROUGH AROUND 07Z...SOME WITH HEAVY RAIN AND MVFR CONDITIONS.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BEGIN DEVELOPING AGAIN
BETWEEN 16-17Z THURSDAY OVER NORTHERN ARIZONA. AVIATION DISCUSSION
NOT UPDATED FOR AMENDMENTS.
&&
.FIRE WEATHER...HIGH PRESSURE WILL GRADUALLY SHIFT EASTWARD LEADING
TO INCREASED SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY. WINDS
WILL GENERALLY BE LIGHT...WITH OUTFLOW-DRIVEN GUSTS FROM 25 TO 45
MPH NEAR THE STRONGER STORMS.
SATURDAY THROUGH MONDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE SATURDAY THROUGH MONDAY AS DRIER AIR MOVES OVER
NORTHERN ARIZONA FROM THE WEST.
&&
PUBLIC..................JJ
AVIATION/FIRE WEATHER...JJ
VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER
INFORMATION.
000
FXUS65 KPSR 020001 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
500 PM MST WED JUL 1 2009
.UPDATE...
UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
THE ATMOSPHERE REMAINS MOIST AND UNSTABLE FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS THIS EVENING. THE DAILY THREAT FOR
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
AS OF 2PM...SAT TRENDS ARE ENCOURAGING...SHOWING CLEARING OVER THE
S-CNTRL AZ DESERTS THIS PAST HOUR OR SO. DOWN OVER SOUTHEAST
AZ...WHERE THEY STARTED WITH LESS CLOUDS THAN THE CENTRAL
DESERTS...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
UNDERWAY. THE RIM IS ALSO STARTING TO FILL IN A BIT...AND WE CAN SEE
CU BUILDING OUT THE WINDOW TO THE SOUTH...AS WELL AS OVER PORTIONS
OF THE NORTHWEST VALLEY.
THE STEERING FLOW REMAINS FAVORABLE...EAST/SOUTHEASTERLY FROM
700-500MB AT 15-20KT. MODIFYING THE /FAIRLY CONTAMINATED/ 12Z PSR
SOUNDING FROM THIS MORNING...AND USING A FORECAST HIGH OF 100 WITH A
MIXING RATIO OF 10.5 G/KG...THE MEAN TEMP METHODOLOGY YIELDS ABOUT
520 J/KG OF CAPE...WITH A SLIVER OF CONVECTIVE INHIBITION. SHOULD
NOT TAKE MUCH TO OVERCOME THE NEG ENERGY-- A GOOD OUTFLOW PUSH FROM
THE EAST OR SOUTHEAST...ALONG WITH A BIT OF COOL ADVECTION IN THE
MID LEVELS FROM THE HIGHER TERRAIN STORMS MIGHT BE ALL IT TAKES TO
GET THINGS GOING IN THE SOUTH-CENTRAL DESERTS EASTWARD.
OUT WEST WHERE A WEAK LINE OF SHOWERS AND THUNDERSTORMS SLOWLY MOVED
NORTHWESTWARD THROUGH THE CWA EARLIER TODAY...THE CLOUDS ARE HANGING
IN THERE...AND KBLH TEMP IS DOWN 13 DEG FROM THIS TIME YESTERDAY.
THAT SAID...WE CANNOT EXPECT THE THERMAL DYNAMICS ALONE TO GET
THINGS GOING OUT THAT WAY...AND WILL NEED TO RELY ON A GREATER DEAL
OF LIFT/SUPPORT ALOFT. NAM AND RUC ARE BOTH SHOWING A DECENT AREA OF
UPPER LEVEL DIVERGENCE ROTATING AROUND THE WESTERN EDGE OF THE HIGH.
THIS AREA OF UPPER LEVEL SUPPORT IS PROGGED TO MOVED NORTHWARD
THROUGH W-CNTRL ARIZONA LATER THIS EVENING AND OVERNIGHT...AND
SHOULD HELP TO OVERCOME THE LACK OF SURFACE HEATING OVER THE WESTERN
DESERTS. AS SUCH...THE FORECAST CALLS FOR SCATTERED SHOWERS AND
THUNDERSTORMS PRETTY MUCH FROM OUR WESTERN CWA BOUNDARY EASTWARD
THROUGH SOUTHERN GILA COUNTY THIS AFTERNOON AND EVENING.
THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF PRODUCING STRONG AND
GUSTY OUTFLOW WINDS IN EXCESS OF 40 MPH...WITH PERIODS OF BRIEF
HEAVY RAIN. BUT IN TERMS OF SEVERE...TEMPS/TD PROFILE DOES NOT
REALLY SUPPORT IT.
TOMORROW THROUGH THE END OF THE WORK WEEK...THE MOISTURE WILL HANG
AROUND...FOR A CONTINUED THREAT OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY...FAVORING THE HIGHER TERRAIN...WITH DESERT
HIGH TEMPS RUNNING A FEW DEG BELOW NORMAL. DIFFICULT TO SAY WITH
MUCH CERTAINTY WHAT THE WEATHER WILL BE 12 HOURS OUT THIS TIME OF
YEAR...AND GOING BEYOND DAY 2 REALLY IS BEST LEFT TO CLIMO.
LATE IN THE WEEKEND AND NEXT WEEK...MODELS CONTINUE TO SHOW A DRIER
WEST/SOUTHWESTERLY FLOW OVER THE REGION...CONFINING THE THREAT FOR
DAILY SHOWERS ANDS THUNDERSTORMS TO THE HIGHER TERRAIN...WHILE
ALLOWING DESERT HIGHS TO WARM BACK TO NEAR NORMAL FOR EARLY JULY.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...CLOUDINESS FROM EARLIER TODAY
HAS THINNED OUT. THIS SHOULD AID IN THE DEVELOPMENT OF INSTABILITY
BUT STORMS HAVE BEEN SLOW TO DEVELOP ON THE LOWER ELEVATIONS. WILL
BE WATCHING STORM ACTIVITY OVER SOUTHEAST ARIZONA AND THE RIM
COUNTRY TO PRODUCE OUTFLOWS WHICH MAY PROVIDE NECESSARY LIFT TO
TRIGGER STORMS OVER THE PHOENIX AREA. WITHOUT THAT...WILL NEED
DYNAMICAL HELP FROM A DISTURBANCE PROGGED TO MOVE NORTHWARD ACROSS
ARIZONA TONIGHT. THIS DISTURBANCE IS NOT READILY EVIDENT IN THE
WATER VAPOR IMAGERY THOUGH. HOWEVER...LOCATION OF MOST ACTIVE
CONVECTION IN SOUTHEAST ARIZONA CORRESPONDS WELL WITH WHERE THIS
FEATURE SHOULD BE. DUE TO THE MEAGER LATE AFTERNOON CONVECTIVE
ACTIVITY...HAVE HELD OFF ON PUTTING IN TEMPO GROUPS FOR
THUNDERSTORMS AND STRONG WINDS IN THE TAFS. BUT POTENTIAL IS STILL
THERE SO AMMENDMENTS WILL QUITE POSSIBLY BE NECESSARY.
KIPL/KBLH AND SURROUNDING AIRFIELDS...DEBRIS CLOUDINESS HAS
CONTINUED TO HOLD ON FROM NEAR THE LOWER COLORADO RIVER VALLEY
WESTWARD. THIS HAS LIKELY INHIBITED INSTABILITY. WITH HIGH DEW
POINTS...AND MODEST AIR TEMPERATURES...ANY STORMS THAT DO DEVELP
WILL BE MORE LIKELY TO PRODUCE BRIEF HEAVY RAIN THAN VERY STRONG
WINDS. CLOUD BASES WOULD LIKELY BE WELL BELOW 10 KFT. DUE TO THE
ABUNDANT MOISTURE...STORM ACTIVITY CANT BE RULED OUT...BUT THIS AREA
SEEMS LESS LIKELY TO BENEFIT FROM THE UPPER DISTURBANCE ADVERTISED
TO MOVE THROUGH ARIZONA. THUS HAVE HELD OFF ON TEMPO GROUPS FOR
THUNDERSTORMS. BUT DUE TO MOISTURE AVAILABILITY...STORM POTENTIAL IS
STILL THERE SO AMMENDMENTS MAY VERY WELL BE NECESSARY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOISTURE WILL BE SLOWLY DECREASING DURING THE PERIOD UNDER A
SOUTHWEST FLOW ALOFT. THERE WILL BE ENOUGH HUMIDITY FOR SLIGHT
CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS MAINLY OVER THE
HIGHER TERRAIN. SUNSHINE WILL DOMINATE THE LOWER DESERTS WITH
TEMPERATURES NEAR NORMAL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...WANEK
AVIATION...AJ
FIRE WEATHER...SIPPLE
000
FXUS65 KPSR 012226 AAA
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM MST WED JUL 1 2009
.UPDATE...UPDATED FIRE WEATHER DISCUSSION.
&&
.SYNOPSIS...
THE ATMOSPHERE REMAINS MOIST AND UNSTABLE FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS THIS EVENING. THE DAILY THREAT FOR
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
AS OF 2PM...SAT TRENDS ARE ENCOURAGING...SHOWING CLEARING OVER THE
S-CNTRL AZ DESERTS THIS PAST HOUR OR SO. DOWN OVER SOUTHEAST
AZ...WHERE THEY STARTED WITH LESS CLOUDS THAN THE CENTRAL
DESERTS...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
UNDERWAY. THE RIM IS ALSO STARTING TO FILL IN A BIT...AND WE CAN SEE
CU BUILDING OUT THE WINDOW TO THE SOUTH...AS WELL AS OVER PORTIONS
OF THE NORTHWEST VALLEY.
THE STEERING FLOW REMAINS FAVORABLE...EAST/SOUTHEASTERLY FROM
700-500MB AT 15-20KT. MODIFYING THE /FAIRLY CONTAMINATED/ 12Z PSR
SOUNDING FROM THIS MORNING...AND USING A FORECAST HIGH OF 100 WITH A
MIXING RATIO OF 10.5 G/KG...THE MEAN TEMP METHODOLOGY YIELDS ABOUT
520 J/KG OF CAPE...WITH A SLIVER OF CONVECTIVE INHIBITION. SHOULD
NOT TAKE MUCH TO OVERCOME THE NEG ENERGY-- A GOOD OUTFLOW PUSH FROM
THE EAST OR SOUTHEAST...ALONG WITH A BIT OF COOL ADVECTION IN THE
MID LEVELS FROM THE HIGHER TERRAIN STORMS MIGHT BE ALL IT TAKES TO
GET THINGS GOING IN THE SOUTH-CENTRAL DESERTS EASTWARD.
OUT WEST WHERE A WEAK LINE OF SHOWERS AND THUNDERSTORMS SLOWLY MOVED
NORTHWESTWARD THROUGH THE CWA EARLIER TODAY...THE CLOUDS ARE HANGING
IN THERE...AND KBLH TEMP IS DOWN 13 DEG FROM THIS TIME YESTERDAY.
THAT SAID...WE CANNOT EXPECT THE THERMAL DYNAMICS ALONE TO GET
THINGS GOING OUT THAT WAY...AND WILL NEED TO RELY ON A GREATER DEAL
OF LIFT/SUPPORT ALOFT. NAM AND RUC ARE BOTH SHOWING A DECENT AREA OF
UPPER LEVEL DIVERGENCE ROTATING AROUND THE WESTERN EDGE OF THE HIGH.
THIS AREA OF UPPER LEVEL SUPPORT IS PROGGED TO MOVED NORTHWARD
THROUGH W-CNTRL ARIZONA LATER THIS EVENING AND OVERNIGHT...AND
SHOULD HELP TO OVERCOME THE LACK OF SURFACE HEATING OVER THE WESTERN
DESERTS. AS SUCH...THE FORECAST CALLS FOR SCATTERED SHOWERS AND
THUNDERSTORMS PRETTY MUCH FROM OUR WESTERN CWA BOUNDARY EASTWARD
THROUGH SOUTHERN GILA COUNTY THIS AFTERNOON AND EVENING.
THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF PRODUCING STRONG AND
GUSTY OUTFLOW WINDS IN EXCESS OF 40 MPH...WITH PERIODS OF BRIEF
HEAVY RAIN. BUT IN TERMS OF SEVERE...TEMPS/TD PROFILE DOES NOT
REALLY SUPPORT IT.
TOMORROW THROUGH THE END OF THE WORK WEEK...THE MOISTURE WILL HANG
AROUND...FOR A CONTINUED THREAT OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY...FAVORING THE HIGHER TERRAIN...WITH DESERT
HIGH TEMPS RUNNING A FEW DEG BELOW NORMAL. DIFFICULT TO SAY WITH
MUCH CERTAINTY WHAT THE WEATHER WILL BE 12 HOURS OUT THIS TIME OF
YEAR...AND GOING BEYOND DAY 2 REALLY IS BEST LEFT TO CLIMO.
LATE IN THE WEEKEND AND NEXT WEEK...MODELS CONTINUE TO SHOW A DRIER
WEST/SOUTHWESTERLY FLOW OVER THE REGION...CONFINING THE THREAT FOR
DAILY SHOWERS ANDS THUNDERSTORMS TO THE HIGHER TERRAIN...WHILE
ALLOWING DESERT HIGHS TO WARM BACK TO NEAR NORMAL FOR EARLY JULY.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...CONSIDERABLE CLOUD COVER ABOVE
12 THSD FT HELD DOWN MUCH OF THE MID DAY CONVECTION. BY 20Z...TEMPS
WERE STILL IN THE MID-UPPER 90S...AND THE AFTERNOON BUILDUPS WERE
JUST STARTING TO FORM NORTHEAST OF GLOBE/MIAMI. STEERING FLOW IS
NEARLY THE SAME AS YESTERDAY...AND LATE AFTERNOON STORMS LIKELY TO
DRIFT TOWARD THE WEST...AND OCNL CIGS COULD DROP TO 6-9 THSD FT. NOT
CALLING FOR LOW VSBYS DUE TO BLOWING DUST AT THIS TIME.
KIPL/KBLH AND SURROUNDING AIRFIELDS...INCREASED LOW/MID LEVEL
MOISTURE LIKELY TO RESULT IN BETTER CHANCES OF STORMS. EARLIER
STORMS BTWN KBLH AND KYUM GAVE VERY LIGHT PRECIP...AND ONLY MODEST
WINDS. AFTERNOON HEATING WILL BE SUFFICIENT TO RESULT IN SCT SHOWERS
AND TSTMS...AND A HIGHER PROBABILITY OF PRECIP. EARLIER SCT CLOUDS
WERE 5-10 THSD FEET AND BKN MID/HIGH LAYERS. THE CLOUDS SHOULD THIN
OUT AND ALLOW ADDITIONAL STORMS TO FORM AND PERSIST INTO TONIGHT.
CONFIDENCE IS STILL LOW FOR ANY BLOWING DUST AT KBLH OR KIPL.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
MOISTURE WILL BE SLOWLY DECREASING DURING THE PERIOD UNDER A
SOUTHWEST FLOW ALOFT. THERE WILL BE ENOUGH HUMIDITY FOR SLIGHT
CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS MAINLY OVER THE
HIGHER TERRAIN. SUNSHINE WILL DOMINATE THE LOWER DESERTS WITH
TEMPERATURES NEAR NORMAL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...WANEK
AVIATION...SIPPLE
FIRE WEATHER...SIPPLE
000
FXUS65 KPSR 012218
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
315 PM MST WED JUL 1 2009
.SYNOPSIS...
THE ATMOSPHERE REMAINS MOIST AND UNSTABLE FOR ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS THIS EVENING. THE DAILY THREAT FOR
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WORK WEEK...ALONG WITH HIGH TEMPERATURES A FEW DEGREES
BELOW NORMAL FOR THIS TIME OF YEAR. LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK...A DRIER SOUTHWESTERLY FLOW WILL CONFINE SHOWERS
AND THUNDERSTORMS TO PRIMARILY THE HIGHER TERRAIN NORTH AND EAST OF
THE PHOENIX AREA...WHILE ALLOWING HIGH TEMPERATURES TO RETURN TO
NEAR NORMAL FOR THIS TIME OF YEAR.
&&
.DISCUSSION...
AS OF 2PM...SAT TRENDS ARE ENCOURAGING...SHOWING CLEARING OVER THE
S-CNTRL AZ DESERTS THIS PAST HOUR OR SO. DOWN OVER SOUTHEAST
AZ...WHERE THEY STARTED WITH LESS CLOUDS THAN THE CENTRAL
DESERTS...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
UNDERWAY. THE RIM IS ALSO STARTING TO FILL IN A BIT...AND WE CAN SEE
CU BUILDING OUT THE WINDOW TO THE SOUTH...AS WELL AS OVER PORTIONS
OF THE NORTHWEST VALLEY.
THE STEERING FLOW REMAINS FAVORABLE...EAST/SOUTHEASTERLY FROM
700-500MB AT 15-20KT. MODIFYING THE /FAIRLY CONTAMINATED/ 12Z PSR
SOUNDING FROM THIS MORNING...AND USING A FORECAST HIGH OF 100 WITH A
MIXING RATIO OF 10.5 G/KG...THE MEAN TEMP METHODOLOGY YIELDS ABOUT
520 J/KG OF CAPE...WITH A SLIVER OF CONVECTIVE INHIBITION. SHOULD
NOT TAKE MUCH TO OVERCOME THE NEG ENERGY-- A GOOD OUTFLOW PUSH FROM
THE EAST OR SOUTHEAST...ALONG WITH A BIT OF COOL ADVECTION IN THE
MID LEVELS FROM THE HIGHER TERRAIN STORMS MIGHT BE ALL IT TAKES TO
GET THINGS GOING IN THE SOUTH-CENTRAL DESERTS EASTWARD.
OUT WEST WHERE A WEAK LINE OF SHOWERS AND THUNDERSTORMS SLOWLY MOVED
NORTHWESTWARD THROUGH THE CWA EARLIER TODAY...THE CLOUDS ARE HANGING
IN THERE...AND KBLH TEMP IS DOWN 13 DEG FROM THIS TIME YESTERDAY.
THAT SAID...WE CANNOT EXPECT THE THERMAL DYNAMICS ALONE TO GET
THINGS GOING OUT THAT WAY...AND WILL NEED TO RELY ON A GREATER DEAL
OF LIFT/SUPPORT ALOFT. NAM AND RUC ARE BOTH SHOWING A DECENT AREA OF
UPPER LEVEL DIVERGENCE ROTATING AROUND THE WESTERN EDGE OF THE HIGH.
THIS AREA OF UPPER LEVEL SUPPORT IS PROGGED TO MOVED NORTHWARD
THROUGH W-CNTRL ARIZONA LATER THIS EVENING AND OVERNIGHT...AND
SHOULD HELP TO OVERCOME THE LACK OF SURFACE HEATING OVER THE WESTERN
DESERTS. AS SUCH...THE FORECAST CALLS FOR SCATTERED SHOWERS AND
THUNDERSTORMS PRETTY MUCH FROM OUR WESTERN CWA BOUNDARY EASTWARD
THROUGH SOUTHERN GILA COUNTY THIS AFTERNOON AND EVENING.
THUNDERSTORMS THAT DEVELOP WILL BE CAPABLE OF PRODUCING STRONG AND
GUSTY OUTFLOW WINDS IN EXCESS OF 40 MPH...WITH PERIODS OF BRIEF
HEAVY RAIN. BUT IN TERMS OF SEVERE...TEMPS/TD PROFILE DOES NOT
REALLY SUPPORT IT.
TOMORROW THROUGH THE END OF THE WORK WEEK...THE MOISTURE WILL HANG
AROUND...FOR A CONTINUED THREAT OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY...FAVORING THE HIGHER TERRAIN...WITH DESERT
HIGH TEMPS RUNNING A FEW DEG BELOW NORMAL. DIFFICULT TO SAY WITH
MUCH CERTAINTY WHAT THE WEATHER WILL BE 12 HOURS OUT THIS TIME OF
YEAR...AND GOING BEYOND DAY 2 REALLY IS BEST LEFT TO CLIMO.
LATE IN THE WEEKEND AND NEXT WEEK...MODELS CONTINUE TO SHOW A DRIER
WEST/SOUTHWESTERLY FLOW OVER THE REGION...CONFINING THE THREAT FOR
DAILY SHOWERS ANDS THUNDERSTORMS TO THE HIGHER TERRAIN...WHILE
ALLOWING DESERT HIGHS TO WARM BACK TO NEAR NORMAL FOR EARLY JULY.
&&
.AVIATION...
PHX/KIWA AND SURROUNDING AIRFIELDS...CONSIDERABLE CLOUD COVER ABOVE
12 THSD FT HELD DOWN MUCH OF THE MID DAY CONVECTION. BY 20Z...TEMPS
WERE STILL IN THE MID-UPPER 90S...AND THE AFTERNOON BUILDUPS WERE
JUST STARTING TO FORM NORTHEAST OF GLOBE/MIAMI. STEERING FLOW IS
NEARLY THE SAME AS YESTERDAY...AND LATE AFTERNOON STORMS LIKELY TO
DRIFT TOWARD THE WEST...AND OCNL CIGS COULD DROP TO 6-9 THSD FT. NOT
CALLING FOR LOW VSBYS DUE TO BLOWING DUST AT THIS TIME.
KIPL/KBLH AND SURROUNDING AIRFIELDS...INCREASED LOW/MID LEVEL
MOISTURE LIKELY TO RESULT IN BETTER CHANCES OF STORMS. EARLIER
STORMS BTWN KBLH AND KYUM GAVE VERY LIGHT PRECIP...AND ONLY MODEST
WINDS. AFTERNOON HEATING WILL BE SUFFICIENT TO RESULT IN SCT SHOWERS
AND TSTMS...AND A HIGHER PROBABILITY OF PRECIP. EARLIER SCT CLOUDS
WERE 5-10 THSD FEET AND BKN MID/HIGH LAYERS. THE CLOUDS SHOULD THIN
OUT AND ALLOW ADDITIONAL STORMS TO FORM AND PERSIST INTO TONIGHT.
CONFIDENCE IS STILL LOW FOR ANY BLOWING DUST AT KBLH OR KIPL.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOIST MONSOON FLOW WILL BEGIN TO WANE AND SHIFT EAST SATURDAY
BRINGING A DRYING TREND TO SOUTHEAST CALIFORNIA AND THE SOUTHWEST
DESERTS OF ARIZONA. TEMPERATURES WILL BE HOT AND DAYTIME HUMIDITY
LEVELS ACROSS THIS AREA WILL DROP BACK INTO THE SINGLE DIGITS.
HIGHER HUMIDITY LEVELS WILL BE COMMON ACROSS THE HIGHER TERRAIN OF
SOUTH-CENTRAL ARIZONA...GENERALLY OVER SOUTHERN GILA COUNTY...IN
ADDITION TO A SLIGHT CHANCE FOR AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...WANEK
AVIATION...SIPPLE
FIRE WEATHER...MEYERS
| 
