251  
FXUS65 KPSR 012310  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
410 PM MST TUE APR 1 2025  
   
UPDATE
 
 
UPDATED AVIATION  
 

 
   
SYNOPSIS
 
 
AN UNSETTLED WEATHER PATTERN IS BRINGING WIDESPREAD GUSTY WINDS TO  
THE REGION TODAY ALONG WITH COOLER TEMPERATURES. THE STRONGEST WINDS  
WILL REMAIN FOCUSED ACROSS THE SOUTHERN GILA COUNTY HIGHER TERRAIN  
AS WELL AS PORTIONS OF SOUTHEAST CALIFORNIA THROUGH THE EVENING INTO  
TONIGHT. SOME CHANCES FOR SHOWERS CAN BE EXPECTED ON WEDNESDAY AND  
ON AGAIN FRIDAY, WITH MOST OF THE ACTIVITY FAVORING THE HIGHER  
TERRAIN AREAS TO THE NORTH AND EAST OF PHOENIX. TEMPERATURES WILL  
REMAIN WELL BELOW NORMAL THROUGH THE REST OF THE WORKWEEK BEFORE A  
WARMING TREND TAKES SHAPE STARTING THIS WEEKEND.  
 

 
   
DISCUSSION
 
 
EARLY AFTERNOON OBJECTIVE ANALYSIS SHOWS A LARGE TROUGH OVER THE  
INTERMOUNTAIN WEST WITH A STRONG MID LEVEL JET CONTINUING TO SAG  
SOUTHWARD ACROSS OUR AREA. THE INCREASED GRADIENT AND HIGHER  
MOMENTUM AIR ALOFT MIXING DOWN HAS LED TO WIDESPREAD GUSTY WINDS  
THIS AFTERNOON. SURFACE OBSERVATIONS AS OF THIS AFTERNOON SHOWED  
PEAK WIND GUSTS UPWARDS OF 25-35 MPH FOR MANY AREAS ACROSS OUR CWA,  
WHILE A FEW AREAS HAVE SEEN GUSTS AROUND 40 MPH. THE STRONGEST WINDS  
WILL CONTINUE TO REMAIN FOCUSED ACROSS THE SOUTHERN GILA COUNTY HIGH  
TERRAIN AS WELL AS PARTS OF SOUTHEAST CALIFORNIA, PARTICULARLY  
PORTIONS OF IMPERIAL COUNTY. WIND ADVISORIES ARE IN EFFECT FOR THESE  
AREAS THROUGH THIS EVENING INTO TONIGHT. GIVEN THESE WINDS, BLOWING  
DUST WILL BE A CONCERN, ESPECIALLY ACROSS IMPERIAL COUNTY WHERE  
WEBCAMS ARE SHOWING DUST BEING LOFTED THIS AFTERNOON. BLOWING DUST  
COULD LEAD TO SOME VISIBILITY REDUCTIONS.  
 
THE LONGWAVE TROUGHING PATTERN WILL SETTLE ACROSS THE DESERT  
SOUTHWEST THROUGH THE END OF THE WEEK, BRINGING MUCH COOLER THAN  
NORMAL TEMPERATURES AS WELL AS SEND A COUPLE OF SHORTWAVES OVER THE  
AREA BRINGING SOME PRECIPITATION CHANCES. WV IMAGERY CURRENTLY SHOWS  
ONE OF THESE SHORTWAVES NEAR THE NORTHERN CALIFORNIA COAST. THIS  
SHORTWAVE WILL CONTINUE TO PROPAGATE TOWARD THE SOUTHEAST AND INTO  
ARIZONA GOING INTO WEDNESDAY AFTERNOON. WHILE MOISTURE WILL BE QUITE  
MEAGER WITH PWATS AROUND 0.3-0.4", THE VORT MAX IS EXPECTED TO  
PROVIDE THE NECESSARY ASCENT NEEDED TO SQUEEZE OUT SOME OF THIS  
MOISTURE. HREF DATA SHOWS LIGHT SHOWERS DEVELOPING ACROSS PARTS OF  
SOUTH-CENTRAL ARIZONA GOING INTO WEDNESDAY AFTERNOON, FAVORING AREAS  
TO THE NORTH OF PHOENIX. FORECAST SOUNDINGS ALSO INDICATE CAPE  
VALUES UP TO 100-200 J/KG BY EARLY WEDNESDAY AFTERNOON AND MAY LEAD  
TO A FEW ISOLATED THUNDERSTORMS. RAINFALL AMOUNTS ACROSS OUR AREA  
WILL REMAIN LIGHT GENERALLY AROUND SEVERAL HUNDREDTHS WITH LOCALLY  
HIGHER AMOUNTS WITH ANY THUNDERSTORMS THAT WERE TO DEVELOP.  
TEMPERATURES WILL BOTTOM OUT WELL BELOW NORMAL WEDNESDAY AS HIGHS  
STRUGGLE TO GET OUT OF THE 60S FOR MANY LOWER DESERT COMMUNITIES.  
TEMPERATURES WILL GRADUALLY TREND UPWARDS FOR THE LATTER PART OF  
THIS WEEK AS HEIGHT FIELDS GRADUALLY RECOVER. TEMPERATURES, HOWEVER,  
WILL CONTINUE TO REMAIN WELL BELOW NORMAL THURSDAY AND FRIDAY AS THE  
REGION REMAINS UNDER TROUGHING. ANOTHER WEATHER SYSTEM WILL TAKE  
SHAPE OVER THE SOUTHWEST CONUS GOING INTO FRIDAY, BRINGING  
ADDITIONAL CHANCES FOR LIGHT SHOWERS ACROSS THE HIGHER TERRAIN FOR  
THE END OF THE WEEK.  
 
GLOBAL ENSEMBLES SHOW THE TROUGHING PATTERN WEAKENING AND SHIFTING  
EAST THIS WEEKEND, LEADING TO A MORE PRONOUNCED WARMING TREND.  
ENSEMBLE CLUSTER ANALYSIS SHOWS GOOD AGREEMENT AMONGST ENSEMBLE  
MEMBERS THAT UPPER LEVEL RIDGING WILL BUILD INTO THE REGION GOING  
INTO THE START OF NEXT WEEK. NBM SHOWS TEMPERATURES RETURNING TO  
NEAR NORMAL READINGS SUNDAY BEFORE WARMING ABOVE NORMAL EARLY NEXT  
WEEK. BY THE MID TO LATTER PART OF NEXT WEEK, ENSEMBLE CLUSTERS  
FAVOR STRONGER RIDGING BUILDING ACROSS THE WEST, BOOSTING  
TEMPERATURES WELL ABOVE SEASONAL NORMALS.  
 

 
   
AVIATION
 
UPDATED AT 2310Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT:  
ABNORMAL TRENDS IN WIND DIRECTIONS, OCCASIONAL STRONGER GUSTS, AND  
PERIODS OF LOWER CIGS WILL ALL BE WEATHER CONCERNS THROUGH WEDNESDAY  
AFTERNOON RESULTING IN LOWER THAN USUAL FORECAST CONFIDENCE. GUSTY  
W/SW WINDS 20-30KT SHOULD PARTIALLY DECOUPLE AND WEAKEN AFTER  
SUNSET, HOWEVER ITS UNLIKELY A WIDESPREAD SHIFT TO EASTERLY WILL  
OCCUR OVERNIGHT. LOFTED DUST WILL BE COMMON DUE TO THESE WIND GUSTS  
AND SLANTWISE VSBY IMPACTED THROUGH MID EVENING. SOME OF THE OUTER  
TERMINALS MAY BRIEFLY BECOME SE OR VARIABLE TOWARDS SUNRISE THOUGH  
CONFIDENCE IS LOW TO MODERATE.  
 
CONFIDENCE IS SOMEWHAT BETTER THAT 050-070 AGL CIGS WILL DEVELOP MID  
MORNING THROUGH EARLY AFTERNOON WITH A TENDENCY FOR BASES TO RISE  
THROUGH THE AFTERNOON THOUGH MAY HOVER NOT FAR FROM THE 060  
THRESHOLD. ANOTHER ROUND OF GUSTY SW WINDS 20-25KT IS LIKELY  
MID/LATE AFTERNOON. ISOLATED SHRA ARE POSSIBLE AROUND THE AIRSPACE  
DURING THE AFTERNOON, HOWEVER COVERAGE AND PROBABILITIES ARE TOO LOW  
TO INCLUDE IN THE TAF PACKAGE. THERE IS MODEL EVIDENCE THAT SOME OF  
THESE SHRA NORTH AND WEST OF PHOENIX MAY CREATE ERRATIC WINDS AND  
CREATE A NORTHERLY COMPONENT LATE AFTERNOON/EARLY EVENING.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
GUSTY WINDS WILL REMAIN THE GREATEST WEATHER ISSUE THROUGH WEDNESDAY  
AFTERNOON UNDER PERIODS OF PASSING HIGH CLOUDS AND POTENTIAL FOR  
ISOLATED LOWER CIGS. WESTERLY GUSTS 25-35KT WILL BE MOST PRONOUNCED  
IN DURATION AND MAGNITUDE AT KIPL WITH ONLY A BRIEF EARLY MORNING  
PERIOD OF WEAKENED DECOUPLING. WHILE SOME SFC VISIBILITY  
RESTRICTIONS ARE POSSIBLE, ITS MORE LIKELY DUST WILL REMAIN LOFTED  
AND IMPACTING SLANTWISE VSBY. GUSTS WILL BE FAR WEAKER AT KBLH,  
HOWEVER WIND DIRECTIONS MAY BE MUCH MORE VARIABLE THROUGH THE  
PERIOD. THERE IS MODEL EVIDENCE OF CIGS 050-070 DEVELOPING DURING  
THE MID MORNING HOURS, THOUGH CONFIDENCE IS ONLY MODERATE.  
 

 
   
FIRE WEATHER
 
 
A WEATHER SYSTEM OVER THE REGION WILL CONTINUE TO PROMOTE WIDESPREAD  
GUSTY WINDS INTO THIS EVENING. THE GUSTY WINDS COMBINED WITH MIN RHS  
AROUND 15-25% WILL CONTINUE TO PROMOTE AREAS OF ELEVATED FIRE  
WEATHER CONDITIONS. THE STRONGEST WINDS WILL REMAIN FOCUSED ACROSS  
PORTIONS OF SOUTHEAST CALIFORNIA, MAINLY ACROSS IMPERIAL COUNTY, AND  
THE HIGHER TERRAIN AREAS OF MARICOPA AND SOUTHERN GILA COUNTIES  
WHERE GUSTS IN EXCESS OF 40 MPH ARE MOST LIKELY TO OCCUR. WINDS  
ELSEWHERE WILL RANGE BETWEEN 20-35 MPH. WEAKER WINDS ARE EXPECTED ON  
WEDNESDAY BUT WILL LIKELY GUST BETWEEN 15-30 MPH, WITH THE STRONGEST  
WINDS EXPECTED ACROSS THE HIGHER TERRAIN AREAS OF SOUTH-CENTRAL  
ARIZONA AND ACROSS IMPERIAL COUNTY. THERE WILL BE SOME MODEST RAIN  
CHANCES (20-50%) ACROSS THE FOOTHILLS AND HIGHER TERRAIN AREAS TO  
THE NORTH AND EAST OF PHOENIX WEDNESDAY AFTERNOON, HOWEVER, THE CWR  
WILL REMAIN LOW AT 10-20%. A FEW ISOLATED THUNDERSTORMS WILL ALSO BE  
POSSIBLE, WHICH COULD LEAD TO LOCALLY ERRATIC WINDS. LIGHTER WINDS  
ARE ANTICIPATED FROM THURSDAY ONWARD. MINRHS WILL RANGE BETWEEN 20-  
30% WEDNESDAY-THURSDAY, BETWEEN 15-25% FRIDAY, AND BETWEEN 10-25%  
OVER THE WEEKEND. OVERNIGHT RECOVERIES WILL BE FAIR TO GOOD ON MOST  
DAYS, GENERALLY BETWEEN 40-70%. WELL-BELOW NORMAL TEMPERATURES ARE  
ANTICIPATED THROUGH THE END OF THE WEEK.  
 

 
   
PSR WATCHES/WARNINGS/ADVISORIES
 
 
AZ...WIND ADVISORY UNTIL 2 AM MST WEDNESDAY FOR AZZ532.  
 
WIND ADVISORY UNTIL 8 PM MST THIS EVENING FOR AZZ558-560>563.  
 
CA...WIND ADVISORY UNTIL 2 AM PDT WEDNESDAY FOR CAZ560-563-565>567.  
 
WIND ADVISORY UNTIL 5 AM PDT WEDNESDAY FOR CAZ562.  
 

 
 

 
 
DISCUSSION...SMITH/LOJERO  
AVIATION...18  
FIRE WEATHER...SMITH/LOJERO  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab AZ Page
The Nexlab CA Page Main Text Page