130  
FXUS65 KPSR 071700  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
1000 AM MST SAT JUN 7 2025  
   
UPDATE  
UPDATED AVIATION DISCUSSION.  
 
 
   
DISCUSSION  
 
KEY MESSAGES:  
 
- DRY CONDITIONS WITH TEMPERATURES PEAKING AROUND 10 DEGREES ABOVE  
NORMAL EARLY NEXT WEEK  
 
- WIDESPREAD MODERATE HEATRISK DURING THE FIRST HALF OF NEXT WEEK  
RELAXING LATER IN THE WEEK  
 
WV IMAGERY CONTINUES TO SHOW A SWATH OF DRY AIR INFILTRATING INTO  
THE REGION FROM A LONG WAVE TROUGH OFF THE SOUTHERN CA COAST. THIS  
IS DRYING THE REGION AS WE WILL SEE SURFACE DEW POINTS IN THE LOW TO  
MID 30'S ACROSS MOST OF THE DESERT SW, AND BELOW NORMAL PWAT VALUES.  
ACCOMPANYING THE DRY AIR, SUBTROPICAL RIDGING, SEEN IN NORTHERN  
MEXICO, HAS BEEN SLOWLY RETROGRADING TOWARDS THE WEST BUILDING HIGH  
PRESSURE ALOFT OVER THE DESERT SW IN A TEMPORARY REX BLOCK PATTERN.  
THESE TOGETHER WILL FACILITATE WARMING AND DRYING CONDITIONS  
REFLECTED IN FORECASTED TEMPERATURES ESPECIALLY FOR THIS WEEKEND AND  
THE EARLY HALF OF NEXT WEEK.  
 
THOUGH THE SUBTROPICAL RIDGE WILL NOT SUFFICIENTLY BUILD DIRECTLY  
OVER THE REGION AS IT RETROGRADES, IT WILL HOWEVER HELP INCREASE THE  
500MB HEIGHTS OVER THE REGION AS IT DOES SO OVER THE NEXT SEVERAL  
DAYS. TODAY PEAK 500MB HEIGHTS ACROSS THE LOWER DESERTS WILL BE NEAR  
585-589 DM WITH HIGH TEMPERATURES EXPECTED TO NEAR 104-106 DEGREES  
ACROSS THE LOWER DESERTS. BY SUNDAY, AND LINGERING INTO THE MIDDLE  
OF NEXT WEEK, TEMPERATURES WILL INCREASE A FEW DEGREES FROM TODAY,  
WITH 500MB HEIGHTS PEAKING NEAR 588-591 DM. THIS WILL LEAD TO HIGH  
TEMPERATURES RANGING BETWEEN 105-110 DEGREES IN THE LOWER DESERTS,  
WITH MONDAY EXPECTED TO BE HOTTEST DAY. TEMPERATURES WILL BE  
SLIGHTLY HIGHER IN SE CALIFORNIA, AND ALONG THE COLORADO RIVER  
VALLEY WITH NBM PROBABILITIES OF REACHING 110 OR ABOVE BETWEEN 50-  
80%, WHILE IN THE PHOENIX METRO THE CHANCES OF 110 OR ABOVE ARE NEAR  
30-60%.  
 
BY LATE NEXT WEEK ENSEMBLE MODELS SUGGEST THE FORMATION OF A TROUGH  
IN THE PACIFIC NW, THAT LOOKS TO DEEPEN ACROSS WESTERN CONUS. THERE  
IS UNCERTAINTY IN HOW AMPLIFIED THIS TROUGHING FEATURE WILL DEVELOP,  
BUT STILL LOOKS TO LOWER MID LEVEL HEIGHTS, RESULTING IN  
TEMPERATURES RETURNING TO NEAR NORMAL BY LATE NEXT WEEK ACROSS THE  
REGION. THIS IS SUPPORTED IN THE NBM INTERQUARTILE TEMPERATURE  
RANGES WITH HIGH TEMPERATURES ON FRIDAY RANGING BETWEEN 100-105, AND  
THE DETERMINISTIC NEARING NORMAL FOR THIS TIME OF YEAR IN THE LOWER  
DESERTS. HOWEVER THIS LOOKS TO BE A BRIEF RELIEF AS SUBTROPICAL  
RIDGING BEGINS TO BUILD BACK INTO THE REGION.  
 
 
   
AVIATION  
UPDATED AT 1700Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:  
NO AVIATION WEATHER CONCERNS ARE EXPECTED THROUGH THE TAF PERIOD  
UNDER CLEAR SKIES. THE OVERALL WIND PATTERN WILL CONTINUE TO  
EXHIBIT THE TYPICAL DIURNAL TENDENCY WITH SPEEDS AOB 10 KTS.  
PERIODS OF LIGHT AND VARIABLE WINDS ARE LIKELY AS WELL DURING THE  
TRANSITION PERIODS.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
NO AVIATION WEATHER CONCERNS UNDER CLEAR SKIES ARE EXPECTED  
THROUGHOUT THE TAF PERIOD. WINDS AT KIPL WILL FLUCTUATE BETWEEN  
THE EAST TO SOUTHEAST THROUGH THIS AFTERNOON BEFORE SHIFTING OUT  
OF THE WEST FOR A PERIOD DURING THE EVENING AND INTO THE OVERNIGHT  
HOURS. WINDS AT KBLH WILL FLUCTUATE BETWEEN THE SOUTHEAST AND  
SOUTHWEST. OVERALL WIND SPEEDS WILL REMAIN AOB 10 KTS. PERIODS OF  
LIGHT AND VARIABLE WINDS ARE LIKELY AS WELL.  
 
 
   
FIRE WEATHER  
 
WARMING TEMPERATURES WITH HIGHS CLIMBING NEAR 10F ABOVE NORMAL  
WILL AFFECT THE REGION THROUGH THE MIDDLE OF NEXT WEEK WHILE THE  
ENVIRONMENT BECOMES PROGRESSIVELY DRIER. AFTERNOON MINRHS WILL  
LARGELY FALL NEAR 10% WITH MORE PREVALENT SINGLE DIGIT RH'S  
TOMORROW AND MONDAY. THIS WILL BE ACCOMPANIED WITH POOR TO  
PROGRESSIVELY FAIRER OVERNIGHT RECOVERY OF 20-40%. WINDS SHOULD  
FOLLOW FAIRLY TYPICAL LATE SPRING CYCLES WITH PERIODS AFTERNOON  
UPSLOPE GUSTINESS. SOMEWHAT MORE BREEZY CONDITIONS MAY ARRIVE TO  
THE REGION TOWARDS THE END OF NEXT WEEK RESULTING IN A SLIGHTLY  
ELEVATED FIRE DANGER.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...NONE.  
CA...NONE.  
 
 
 
 
DISCUSSION...RYAN  
AVIATION...SMITH/YOUNG  
FIRE WEATHER...RYAN/18  
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