521  
FXUS65 KPSR 131722  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
1022 AM MST TUE MAY 13 2025  
   
UPDATE  
UPDATED 18Z AVIATION DISCUSSION.  
 
 
   
SYNOPSIS  
 
GUSTY WINDS AND ELEVATED TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS  
WILL BE THE MAIN WEATHER CONCERNS AGAIN TODAY, AS A WEATHER SYSTEM  
PUSHES THROUGH THE REGION. TEMPERATURES WILL ALSO FALL BELOW  
NORMAL THROUGH WEDNESDAY BEFORE WARMING BACK UP TO NEAR NORMAL  
READINGS FOR THE END OF THE WORKWEEK. GUSTY WINDS AND COOLER THAN  
NORMAL TEMPERATURES WILL ONCE AGAIN BE POSSIBLE THIS WEEKEND INTO  
EARLY NEXT WEEK.  
 
 
   
DISCUSSION  
 
SATELLITE WV IMAGERY AND RAP ANALYSIS EARLY THIS MORNING SHOWED A  
PACIFIC TROUGH CONTINUING TO ADVANCE INLAND ALONG THE WEST COAST  
WHILE EXPANSIVE MID AND HIGH CLOUD COVERAGE CONTINUES TO OVERSPREAD  
ARIZONA IN RESPONSE TO THE APPROACHING WEATHER SYSTEM. THE  
APPROACHING SYSTEM LED TO WIDESPREAD GUSTY WINDS YESTERDAY WITH MANY  
PLACES SEEING GUSTS UPWARDS OF 25-35 MPH AND LOCALLY HIGHER ACROSS  
PARTS OF SOUTHEAST CALIFORNIA. STRONG WINDS WILL CONTINUE TO BE THE  
PRIMARY SENSIBLE WEATHER IMPACT AS WIDESPREAD GUSTS AROUND 25-35 MPH  
ARE AGAIN IN THE FORECAST FOR TODAY WITH THE STRONGEST WINDS  
FAVORING PARTS OF IMPERIAL COUNTY AND THE RIDGETOPS IN SOUTHERN GILA  
COUNTY. A WIND ADVISORY REMAINS IN EFFECT FOR PARTS OF IMPERIAL  
COUNTY, INCLUDING THE IMPERIAL VALLEY, TODAY WHERE GUSTS IN EXCESS  
OF 40 MPH ARE MOST LIKELY TO OCCUR. THESE STRONG WINDS WILL BE  
CAPABLE OF GENERATING A FEW DUST CHANNELS WHICH COULD LEAD TO SOME  
LOCALIZED VISIBILITY RESTRICTIONS. ADDITIONALLY, THE DRY NATURE OF  
THIS SYSTEM COMBINED WITH THE STRONG WINDS WILL PROMOTE ELEVATED TO  
LOCALLY CRITICAL FIRE WEATHER CONDITIONS, PARTICULARLY ACROSS THE  
HIGHER TERRAIN EAST OF PHOENIX WHERE A RED FLAG WARNING REMAINS IN  
EFFECT FOR TODAY.  
 
WHILE STRONG WINDS WILL BE THE GREATEST WEATHER IMPACT, HEIGHT FALLS  
WITH THE PASSAGE OF THE TROUGH WILL PUSH 500 MB HEIGHTS DOWN TO  
AROUND 570-574 DM WHILE THE GREATEST NEGATIVE HEIGHT ANOMALIES WILL  
RESIDE NORTH OF OUR AREA. TEMPERATURES IN RESPONSE TO THIS TROUGH  
WILL DROP BELOW NORMAL OVER THE NEXT COUPLE OF DAYS. FORECAST HIGHS  
FOR TODAY RANGE FROM LOW TO MID 80S ACROSS SOUTHEAST CALIFORNIA AND  
SOUTHWEST ARIZONA TO MID/UPPER 80S TO AROUND 90 DEGREES ACROSS SOUTH-  
CENTRAL ARIZONA. HIGHS WEDNESDAY FURTHER DROP ACROSS SOUTH-CENTRAL  
ARIZONA AS MOST LOWER DESERT LOCALES ARE FORECAST TO TOP OUT IN THE  
MID TO UPPER 80S.  
 
FOLLOWING THE PASSAGE OF THE AFOREMENTIONED TROUGH, BROAD  
CYCLONIC/QUASI ZONAL FLOW WILL PREVAIL OVER THE SOUTHWEST CONUS  
THROUGH THE LATTER HALF OF THIS WEEK. NBM INDICATES MINIMAL IQR  
SPREAD YIELDING EXCELLENT CONFIDENCE THAT TEMPERATURES WILL RETURN  
TO NEAR NORMAL READINGS FOR THE LATTER HALF OF THIS WEEK AS HEIGHTS  
GRADUALLY REBOUND DURING THIS TIME. FORECAST HIGHS BY THE END OF THE  
WORKWEEK RETURN TO SEASONABLE READINGS IN THE LOWER 90S ACROSS THE  
LOWER DESERTS. FORECAST UNCERTAINTY THEN INCREASES FOR THE WEEKEND  
INTO EARLY NEXT WEEK AS OPERATIONAL AND ENSEMBLE GUIDANCE SHOW  
ANOTHER TROUGH PROPAGATING INTO THE DESERT SOUTHWEST. ENSEMBLE  
CLUSTER ANALYSIS REVEALS DISCREPANCIES AMONGST ENSEMBLE MEMBERSHIP  
REGARDING THE DEPTH OF THIS TROUGH. FOR NOW, THERE IS GOOD AGREEMENT  
THAT WE WILL SEE ANOTHER ROUND OF GUSTY WINDS AND COOLER  
TEMPERATURES LATE WEEKEND INTO EARLY NEXT WEEK, WHILE POPS AT THIS  
TIME ARE FOCUSED OVER THE NORTHERN ARIZONA HIGH TERRAIN.  
 
 
   
AVIATION  
UPDATED AT 1720Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:  
GUSTY WSW WINDS WILL BE THE PRIMARY AVIATION CONCERN DURING THE  
TAF PERIOD UNDER FEW HIGH CLOUDS. GUSTS TO AROUND 25 KTS WILL PICK  
UP OVER THE NEXT FEW HOURS AND PERSIST INTO EARLY THIS EVENING,  
EVENTUALLY SUBSIDING BY 03-04Z. THOUGH W-SW WINDS ARE ANTICIPATED  
TO PREVAIL THROUGH THE OVERNIGHT HOURS, DIRECTIONS MAY TRY TO  
SHIFT S-SE OR BECOME VRB FOR A PERIOD EARLY WEDNESDAY MORNING.  
CONFIDENCE IS TOO LOW TO INCLUDE S-SE WINDS EARLY WEDNESDAY  
MORNING AT ANY OF THE TERMINALS EXCEPT FOR KIWA, SO HAVE OPTED FOR  
PREVAILING VRB GROUPS AT THE OTHER SITES, WITH SPEEDS AOB 6 KTS  
DURING THAT TIMEFRAME.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
GUSTY WINDS AND THE POTENTIAL FOR BRIEF VISIBILITY RESTRICTIONS  
FROM BLOWING DUST WILL CONTINUE TO BE THE PRIMARY AVIATION  
CONCERNS AT THE SE CALIFORNIA TERMINALS UNDER FEW OCCASIONAL HIGH  
CLOUDS. WINDS WILL REMAIN WESTERLY AT KIPL AND SOUTHWESTERLY AT  
KBLH THROUGH MUCH OF THE TAF PERIOD AND ARE EXPECTED TO SHIFT NW  
WEDNESDAY MORNING AFTER SUNRISE. AT KIPL, GUSTS OF 25-30 KT WILL  
CONTINUE THROUGH THE AFTERNOON AND WILL THEN PICK UP LATE THIS  
AFTERNOON WITH GUSTS OF 30-35 KT EXPECTED THROUGH THE EVENING.  
GUSTS WILL FINALLY START TO SUBSIDE DURING THE OVERNIGHT/EARLY  
MORNING HOURS WEDNESDAY. AT KBLH, WINDS WILL PICK UP OVER THE NEXT  
FEW HOURS, WITH GUSTS TO AROUND 25 KTS BECOMING COMMON DURING THE  
AFTERNOON AND EARLY EVENING.  
 
 
   
FIRE WEATHER  
 
ELEVATED TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS WILL  
INCREASE AGAIN GOING INTO THIS AFTERNOON AS STRONG WINDS AND DRY  
CONDITIONS CONTINUE IN RESPONSE TO AN APPROACHING WEATHER SYSTEM.  
GUSTY WEST TO SOUTHWEST WINDS WILL PICK UP BY LATE THIS MORNING  
INTO THE AFTERNOON, WITH WIDESPREAD GUSTS CLIMBING UPWARDS OF  
25-35 MPH AND LOCALIZED GUSTS TO AROUND 40 MPH ACROSS PORTIONS OF  
IMPERIAL COUNTY AND ALONG RIDGETOPS IN SOUTHERN GILA COUNTY. MIN  
RHS THIS AFTERNOON WILL BE AROUND 8-15% FOR MOST AREAS WHILE  
OVERNIGHT MAX RHS CLIMB INTO THE 25-50% RANGE. EXPECT A RETURN TO  
MORE TYPICAL DIURNAL WIND PATTERNS FOR THE LATTER HALF OF THIS  
WEEK, WITH TYPICAL AFTERNOON UPSLOPE BREEZES FOR THE TIME OF  
YEAR. GUSTY WINDS ARE EXPECTED TO INCREASE AGAIN THIS WEEKEND AS  
ANOTHER WEATHER SYSTEM PUSHES INTO THE REGION.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...RED FLAG WARNING UNTIL 8 PM MST THIS EVENING FOR AZZ133.  
 
CA...WIND ADVISORY UNTIL 5 AM PDT WEDNESDAY FOR CAZ562.  
 
WIND ADVISORY UNTIL 2 AM PDT WEDNESDAY FOR CAZ563-566-567.  
 
 
 
 
 
DISCUSSION...SMITH  
AVIATION...WHITTOCK  
FIRE WEATHER...SMITH  
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