684  
FXUS65 KPSR 110554  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
1054 PM MST SAT MAY 10 2025  
   
UPDATE
 
UPDATED AVIATION DISCUSSION.  
 

 
   
SYNOPSIS
 
 
HOTTEST TEMPERATURES SO FAR THIS YEAR ARE EXPECTED TODAY AND  
TOMORROW, WITH HIGHS ACROSS THE LOWER DESERT RANGING FROM 100-108.  
THIS IS DUE TO HIGH PRESSURE ALOFT FULLY SETTLING OVER THE REGION.  
WIDESPREAD MODERATE HEATRISK TO LOCALIZED MAJOR HEATRISK WILL  
LAST THROUGH THE WEEKEND BECAUSE OF THESE TEMPERATURES. DAILY  
BREEZY CONDITIONS HAVE DEVELOPED THIS MORNING AND WILL CONTINUE  
INTO NEXT WEEK AS THE NEXT WEATHER SYSTEM MOVES INTO THE REGION.  
ALTHOUGH THIS SYSTEM WILL BE DRY, TEMPERATURE WILL COOL AS IT  
REACHES THE REGION.  
 

 
   
DISCUSSION
 
 
UPPER LEVEL WV IMAGERY SHOWS RIDGING ALONG WITH DRY AIR ALOFT  
OVER THE REGION. PEAK H5 HEIGHTS TODAY AND TOMORROW WILL GENERALLY  
BE BETWEEN 584-586, CAUSING HIGH TEMPERATURES TO WARM TO 100-108  
DEGREES ACROSS THE LOWER DESERT, AND UPPER 80S TO UPPER 90S IN  
THE HIGHER TERRAIN. THESE TEMPERATURES HAVE RESULTED IN  
WIDESPREAD MODERATE HEATRISK AND SOME MORE LOCALIZED MAJOR  
HEATRISK FOR BOTH TODAY AND TOMORROW. SMART HEAT SAFETY OVER THE  
WEEKEND WILL BE IMPORTANT. SO LIMIT OUTDOOR TIME, WEAR SUNSCREEN,  
WEAR LIGHT/LOOSE FITTING CLOTHING AND STAY HYDRATED. WHILE HIGH  
TEMPERATURES TOMORROW ARE EXPECTED TO BE SIMILAR TO TODAY'S, AN  
INCREASE IN CLOUD COVERAGE COULD KEEP SOME LOCATIONS FROM REACHING  
THE CURRENT NBM FORECAST.  
 
TODAY BREEZY CONDITIONS HAVE DEVELOPED OUT OF THE EAST/SOUTHEAST  
AS THE PRESSURE GRADIENT TIGHTENED BETWEEN THE LOW PRESSURE OVER  
LOUISIANA AND THE HIGH PRESSURE CENTERED OVERHEAD TODAY. WIND  
GUSTS TODAY WILL BE DIMINISHING THROUGHOUT THE AFTERNOON/EVENING  
AS THE PEAK GUSTS, 25-35 MPH, WERE MOSTLY THIS MORNING. TOMORROW A  
SIMILAR WIND PATTERN WILL TAKE HOLD BUT SPEEDS WILL BE ROUGHLY 5  
MPH LOWER.  
 
GLOBAL ENSEMBLES SHOW THE LOW PRESSURE, CURRENTLY IN THE GULF OF  
ALASKA, MOVING ONSHORE IN THE PACIFIC NORTHWEST BY LATE THIS  
WEEKEND/VERY EARLY NEXT WEEK. DURING THE EARLY APPROACH OF THIS  
SYSTEM (MONDAY) TEMPERATURES IN THE LOWER DESERTS WILL EVER SO  
SLIGHTLY COOL WITH FORECASTED AFTERNOON HIGHS IN THE HIGH 90S, TO  
LOW 100S. AS THIS SYSTEM MOVES FURTHER INTO WESTERN CONUS  
(TUESDAY/WEDNESDAY), WE WILL SEE ADDITIONAL COOLING, WITH  
WEDNESDAY FORECAST HIGH TEMPERATURES IN THE MID TO HIGH 80S,  
WHICH WILL BE BELOW NORMAL. HOWEVER, ENSEMBLES AGREE THAT THE  
CENTER OF THE LOW WILL STAY WELL TO OUR NORTH, RESULTING IN  
OVERALL LACKLUSTER COOLING FOR THE REGION. GLOBAL ENSEMBLE MODELS  
START TO DIFFER A LITTLE ON THE HOW LONG THE LOW WILL LINGER OVER  
WESTERN CONUS. HOWEVER, MOST MEMBERS SHOW THE LOW WEAKENING, BUT  
LINGERING ACROSS OUR REGION FOR THE LATTER HALF OF NEXT WEEK. THIS  
WOULD ALLOW TEMPERATURES TO WARM TO NEAR NORMAL FOR THE END OF  
NEXT WEEK.  
 

 
   
AVIATION
 
UPDATED AT 0554Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:  
EASTERLY WINDS WILL REMAIN ELEVATED AROUND 6-12 KTS THROUGH EARLY  
SUNDAY MORNING. ANOTHER BREEZY MIXOUT IS EXPECTED SUNDAY MORNING  
BETWEEN 15-19Z, WITH GUSTS UP TO 20-25 KTS. EASTERLY WINDS WILL  
SUBSIDE AND VEER SOUTHERLY MIDDAY AND THERE WILL LIKELY BE A  
PERIOD OF 150V220 DEGREES FROM 20-23Z BEFORE SHIFTING MORE  
SOUTHWESTERLY TOWARD LATE AFTERNOON. MID AND HIGH CLOUDS WILL  
INCREASE TONIGHT AND PERSIST THROUGH SUNDAY, WITH BASES STAYING  
ABOVE 15K FT AGL.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
A N/NE DRAINAGE WIND IS EXPECTED THROUGH TONIGHT/EARLY MORNING AT  
KBLH BEFORE SHIFTING S/SE BY LATE MORNING SUNDAY. WINDS AT KIPL  
WILL SEE PERIODS OF LIGHT W/SW AND LIGHT VARIABILITY THROUGH THE  
OVERNIGHT HOURS FOLLOWED BY A PREVAILING E/SE WIND MOST OF THE DAY  
SUNDAY. WINDS ARE THEN EXPECTED TO TURN MORE W/SW AT BOTH  
TERMINALS SUNDAY EVENING, WITH POTENTIAL FOR 20-25 KT SUNDOWNER  
WINDS AT KIPL. SCT TO BKN HIGH CLOUDS WILL PREVAIL THROUGH THE TAF  
PERIOD.  
 

 
   
FIRE WEATHER
 
 
WITH HIGH PRESSURE FIRMLY OVERHEAD THIS WEEKEND, TEMPERATURES WILL  
CLIMB INTO THE 100-108 DEGREE RANGE ACROSS THE LOWER DESERTS AND  
MOST HIGHER ELEVATIONS WILL SEE HIGH TEMPERATURES RANGING FROM THE  
UPPER 80S TO UPPER 90S. MINRHS WILL BE IN THE 7-15% RANGE THROUGH  
MONDAY. BREEZY CONDITIONS HAVE DEVELOPED THIS MORNING ACROSS  
SOUTHERN AND CENTRAL ARIZONA WITH GUSTS OF 25-35 MPH OUT OF THE  
EAST/SOUTHEAST. SPEEDS WILL DECREASE A LITTLE THROUGHOUT THE  
AFTERNOON/EVENING. A SIMILAR WIND PATTERN IS EXPECTED TOMORROW  
WITH SPEEDS AROUND 5 MPH LOWER THAN TODAY. THE BREEZY CONDITIONS  
WILL ALSO EXPAND INTO THE WESTERN DISTRICTS TOMORROW. THESE BREEZY  
CONDITIONS AND LOW RHS COULD RESULT IN SOME ELEVATED FIRE DANGER  
IN SOME AREAS THIS WEEKEND. A LOW PRESSURE SYSTEM WILL MOVE INTO  
THE REGION EARLY NEXT WEEK. WHILE THIS SYSTEM WILL BRING COOLER  
CONDITIONS IT WILL ALSO BRING MORE BREEZY TO WINDY CONDITIONS  
LIKELY LEADING TO A CONTINUATION OF ELEVATED FIRE DANGER.  
 

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

 
 

 
 
DISCUSSION...BERISLAVICH/RYAN  
AVIATION...BENEDICT  
FIRE WEATHER...BERISLAVICH/RYAN  
 
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