Forecast-Discussion
000
FXUS65 KPSR 172126
AFDPSR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
226 PM MST THU MAY 17 2012
.SYNOPSIS...
TEMPERATURES WILL COOL SLIGHTLY FRIDAY AND SATURDAY AS A DRY COLD
FRONT MOVES THROUGH THE REGION. GUSTY WINDS FRIDAY AFTERNOON BEHIND
THE COLD FRONT...IN COMBINATION WITH VERY DRY CONDITIONS...WILL LEAD
TO HIGH FIRE DANGER ACROSS MUCH OF THE EASTERN HALF OF ARIZONA.
CLEAR SKIES...LIGHTER WIND...AND WARMER TEMPERATURES WILL DEVELOP
SUNDAY AND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...
SHORTWAVE TROUGH CURRENTLY CENTERED OVER THE CENTRAL CALIFORNIA
COAST WILL QUICKLY DROP SOUTHEASTWARD TONIGHT INTO NORTHERN ARIZONA.
VERY LITTLE MOISTURE ASSOCIATED WITH THE SYSTEM WILL AT MOST PROVIDE
THE SOUTHERN HALF OF ARIZONA WITH A BRIEF PERIOD OF SCATTERED TO
BROKEN MID AND HIGH CLOUDS MAINLY LATE TONIGHT AND FRIDAY MORNING.
500MB HEIGHTS FALL FROM AROUND 583DM TODAY TO NEAR 576-579DM DURING
THE DAY FRIDAY. THE HEIGHT FALLS ALONG WITH A DROP OF AROUND 3-4
DEGREES AT 850MB WILL LEAD TO HIGHS FRIDAY CLOSER TO NORMAL.
THE BIGGEST IMPACT OF FRIDAY/S SYSTEM WILL BE THE DANGEROUS FIRE
WEATHER CONDITIONS ACROSS EASTERN PORTIONS OF SOUTH CENTRAL ARIZONA
AND THROUGHOUT SOUTHEAST AND EAST CENTRAL ARIZONA. A TIGHTENING
PRESSURE GRADIENT LATE TONIGHT INTO FRIDAY WITH WEST TO
SOUTHWESTERLY 20-25 KNOT 850 WINDS DEVELOPING WILL LEAD TO BREEZY TO
WINDY CONDITIONS FROM MARICOPA COUNTY EASTWARD. DRY FORECAST
SOUNDINGS AND DAYTIME HEATING WILL PROBABLY ALLOW MIXING TO AROUND
700MB WHICH WOULD RESULT IN SOME 25-35 KNOTS WITH THE HIGHEST GUSTS
ACROSS HIGHER TERRAIN AREAS TO THE NORTH AND EAST. THESE CONDITIONS
HAVE LED THE ISSUANCE OF A RED FLAG WARNING FROM LATE FRIDAY MORNING
THROUGH EARLY FRIDAY EVENING FOR EAST MARICOPA...NORTHERN
PINAL...AND GILA COUNTIES.
THE TROUGH WILL EXIT FRIDAY NIGHT WITH WEST TO NORTHWESTERLY UPPER
FLOW CONTINUING THROUGH SATURDAY. 500MB HEIGHTS START TO REBOUND
SATURDAY...BUT HIGHS WILL BE SIMILAR TO A COUPLE DEGREES WARMER THAN
FRIDAY. UPPER RIDGING BUILDS IN FROM THE WEST SUNDAY AND
MONDAY...LEADING TO SHARPLY WARMER HIGH TEMPERATURES UNDER MOSTLY
SUNNY OR SUNNY SKIES. BY MONDAY AFTERNOON...500MB HEIGHTS OVER THE
LOWER DESERTS WILL REACH TO AROUND 585-588DM AND MANY HOTTER DESERTS
WILL REACH OR EXCEED 105 DEGREES.
BY TUESDAY AND WEDNESDAY...LONG RANGE MODELS DIVERGE WITH THE MORE
PROGRESSIVE GFS SHOWING AN OPEN TROUGH DIGGING INTO NORTHERN ARIZONA
TUESDAY NIGHT. THE EUROPEAN IS KEEPING THE TROUGH MUCH FURTHER NORTH
ACROSS NORTHERN NEVADA AND NORTHERN UTAH. FOR NOW...KEEPING WITH A
BLEND OF THE MODELS WHICH STILL RESULTS IN HIGH TEMPERATURES NEAR OR
JUST ABOVE 100 ACROSS THE LOWER DESERTS TUESDAY THROUGH THURSDAY.
&&
.AVIATION...
SOUTH CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL.
SOME OCCASIONAL AFTERNOON BREEZINESS THIS AFTERNOON WILL DIMINISH
AROUND SUNSET. EXPECT MOSTLY CLEAR SKIES AND LIGHT DIURNAL WINDS
TONIGHT...WITH WINDS INCREASING AROUND NOON FRIDAY. OTHERWISE EXPECT
GOOD VISIBILITIES WITH NO AVIATION CONCERNS THROUGHOUT THE TAF
PERIOD.
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH.
EXPECT BREEZY TO WINDY SOUTHERLY WINDS THROUGH AROUND MIDNIGHT.
OTHERWISE LIGHT WINDS AND GOOD VISIBILITIES ARE ANTICIPATED.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
HOT AND DRY CONDITIONS WITH ABOVE NORMAL TRIPLE DIGIT HIGH
TEMPERATURES ARE ANTICIPATED THROUGH THURSDAY. CRITICAL FIRE WEATHER
THRESHOLDS MAY BE POSSIBLE ON TUESDAY AS WINDS ARE EXPECTED TO
INCREASE IN MOST AREAS AS THE NEXT TROUGH MOVES THROUGH. BREEZY
CONDITIONS ARE ALSO ANTICIPATED IN THE COLORADO RIVER VALLEY AND
SOUTHEAST CALIFORNIA ON THURSDAY AFTERNOON. MINIMUM HUMIDITY VALUES
ARE EXPECTED IN THE MID TO UPPER SINGLE DIGITS. EXPECT POOR TO FAIR
OVERNIGHT RECOVERIES EXCEPT FOR SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA THERE THEY SHOULD BE FAIR.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...RED FLAG WARNING FROM 11 AM TO 8 PM MST FRIDAY AZZ023-024-028.
CA...NONE.
&&
$$
NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT
WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
AVIATION...SAWTELLE
FIRE WEATHER...SAWTELLE
NWS PSR Office Area Forecast Discussion
