200  
FXUS65 KPSR 312340  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
440 PM MST SUN MAY 31 2026  
   
UPDATE
 
00Z AVIATION DISCUSSION.  
 

 
   
KEY MESSAGES
 
 
- NEAR NORMAL TEMPERATURES TODAY WARM TO SLIGHTLY ABOVE NORMAL  
TOMORROW AND WILL BE NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THIS  
UPCOMING WEEK.  
 
- DRY CONDITIONS WITH MOSTLY SUNNY SKIES AND LIGHT SEASONAL WINDS  
WITH OCCASIONAL AFTERNOON BREEZINESS ARE EXPECTED THROUGH THIS  
UPCOMING WEEK.  
 

 
   
SHORT TERM /TODAY THROUGH WEDNESDAY/
 
 
UPPER-LEVEL WATER VAPOR SATELLITE IMAGERY AND 500MB RAP ANALYSIS  
SHOW AN OMEGA BLOCK STARTING TO DEVELOP WITH A STRONG CLOSED LOW IN  
THE GULF OF ALASKA, ANOTHER STRONG CLOSED LOW OVER NEW ENGLAND, AND  
A RIDGE STARTING TO DEVELOP ACROSS CENTRAL CONUS. WITH THE OMEGA  
BLOCK STARTING TO DEVELOP, UPPER LEVEL HEIGHTS ACROSS THE DESERT  
SOUTHWEST HAVE STARTED TO RISE WITH FLOW ALOFT BECOMING MORE  
SOUTHWESTERLY VS QUASI-ZONAL. H5 HEIGHTS ACROSS AZ AND SOUTHERN CA  
RANGE FROM 580-584 DM, WHICH IS AROUND 4 DM MORE THAN H5 HEIGHTS  
YESTERDAY. THIS INCREASE IN HEIGHTS ALOFT WILL RESULT IN TEMPERATURES  
CONTINUING TO WARM. AFTERNOON HIGH TEMPERATURES WILL BE NEAR  
NORMAL TODAY WITH HIGHS IN THE UPPER 90S TO AROUND 100 DEGREES  
ACROSS THE LOWER DESERTS AND IN THE 90S ACROSS THE HIGHER TERRAIN.  
 
THE OMEGA BLOCK PATTERN WILL CONTINUE TO AMPLIFY AND LOOKS TO  
MAXIMIZE DURING THE MIDDLE OF THE WEEK, WHEN THE HOTTEST TEMPERATURES  
OF THE WEEK ARE EXPECTED. AS A RESULT OF THE AMPLIFYING PATTERN,  
H5 HEIGHTS LOOK TO CLIMB TO 585-588 DM OVER OUR REGION AND THUS  
TEMPERATURES WILL CLIMB TO SLIGHTLY ABOVE NORMAL ON MONDAY AND  
THEN WARM ANOTHER DEGREE OR TWO FOR TUESDAY AND WEDNESDAY.  
AFTERNOON HIGH TEMPERATURES WILL BE IN THE 100-105 DEGREE RANGE  
ACROSS THE LOWER DESERTS AND IN THE MID TO UPPER 90S TO AROUND 100  
DEGREES ACROSS THE HIGHER TERRAIN AREAS DURING THE FIRST HALF OF  
THE WORKWEEK. MORNING LOW TEMPERATURES WILL ALSO BE ON THE RISE  
THIS WEEK WITH MORNING LOWS RANGING FROM THE MID 60S TO MID 70S  
ACROSS THE LOWER DESERTS AND THE UPPER 50S TO MID 60S ACROSS THE  
HIGHER TERRAIN AREAS. THE COMBINATION OF THESE MORNING LOWS AND  
AFTERNOON HIGHS WILL RESULT IN LOCALIZED AREAS OF MODERATE  
HEATRISK DEVELOPING AS EARLY AS MONDAY, MAINLY ACROSS THE LOWER CO  
RIVER VALLEY. AS TEMPERATURES WARM, REMEMBER TO PRACTICE SMART  
HEAT SAFETY BY DRINKING PLENTY OF WATER AND ELECTROLYTES AND  
LIMITING YOUR TIME OUTDOORS (ESPECIALLY DURING THE AFTERNOONS).  
 
ASIDE FROM THE WARMING TEMPERATURES, WITH HIGH PRESSURE BUILDING  
OVER OUR REGION, DRY CONDITIONS WITH MOSTLY CLEAR SKIES WILL  
CONTINUE THROUGH AT LEAST THE MIDDLE OF THE WEEK. WITH NO WEATHER  
SYSTEMS MOVING THROUGH THE REGION, WIND SPEEDS WILL FOLLOW TYPICAL  
DIURNAL TRENDS ALONG WITH SEASONAL LIGHT WIND SPEEDS AND OCCASIONAL  
MODEST AFTERNOON BREEZINESS.  
 

 
   
LONG TERM /THURSDAY THROUGH SATURDAY/
 
 
MODEL ENSEMBLES ARE IN GOOD AGREEMENT THAT THE UPPER LEVEL RIDGE  
OVER THE CENTRAL PLAINS WILL BEGIN SHIFTING EASTWARD AS EARLY AS  
WEDNESDAY, THEN AFTERWARDS A CUT OFF LOW WILL DEVELOP THURSDAY IN  
NORTHERN MEXICO AND IS WHAT WILL HELP TEMPERATURES TREND BACK  
TOWARDS NORMAL LATE NEXT WEEK. AFTERNOON HIGHS THURSDAY WILL NOT  
FEEL THE FULL EFFECT OF THIS DEVELOPING LOW AS H5 HEIGHTS WILL  
REMAIN BETWEEN 582-585 DAM. WHILE THESE HEIGHTS WILL BE SLIGHTLY  
LOWER THAN EARLIER IN THE WEEK, TEMPERATURES WILL REMAIN GENERALLY  
BETWEEN 101F-104F DEGREES. STARTING FRIDAY TEMPERATURES WILL BEGIN  
RETURNING TO NEAR NORMAL, ~100F, AS HEIGHTS CONTINUE TO LOWER  
SLIGHTLY IN RESPONSE TO THE DEVELOPING LOW TO THE SOUTH OF THE  
REGION. THESE NEAR NORMAL TEMPERATURES ARE LIKELY TO PERSIST THROUGH  
NEXT WEEKEND.  
 

 
   
AVIATION
 
UPDATED AT 2340Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, AND KDVT; AND  
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
 
NO AVIATION WEATHER CONCERNS ARE ANTICIPATED UNDER GENERALLY  
CLEAR SKIES THROUGHOUT THE TAF PERIOD. THE OVERALL WIND PATTERN  
WILL EXHIBIT TYPICAL DIURNAL FLUCTUATIONS WITH SPEEDS GENERALLY  
REMAINING AOB 10 KTS. THERE MAY ALSO BE PERIODS OF LIGHT AND VRB  
TO CALM CONDITIONS AT TIMES, PARTICULARLY PRIOR TO THE ONSET OF  
ANY WIND SHIFTS.  
 

 
   
FIRE WEATHER
 
 
LIGHT WINDS WILL MAINLY FOLLOW THEIR DIURNAL UPSLOPE/UPVALLEY AND  
NOCTURNAL DRAINAGE PATTERNS THROUGH MOST OF THIS UPCOMING WEEK. SOME  
OCCASIONAL MODEST AFTERNOON BREEZINESS IS EXPECTED AS WELL.  
TEMPERATURES WILL BE NEAR NORMAL TODAY BEFORE RISING TO SLIGHTLY  
ABOVE NORMAL FOR THE MAJORITY OF THE UPCOMING WORKWEEK. MINRHS  
WILL BE AROUND 5-15% THROUGH THE UPCOMING WEEK WITH POOR OVERNIGHT  
RECOVERIES (15-35%). THE DRIEST DAYS (LOWEST HUMIDITIES) ARE  
EXPECTED MID WEEK.  
 

 
   
PSR WATCHES/WARNINGS/ADVISORIES
 
 
AZ...NONE.  
CA...NONE.  

 
 

 
 
SHORT TERM...BERISLAVICH  
LONG TERM...RYAN  
AVIATION...SALERNO  
FIRE WEATHER...BERISLAVICH  
 
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