723  
FXUS65 KPSR 161723  
AFDPSR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PHOENIX AZ  
1023 AM MST FRI MAY 16 2025  
   
UPDATE  
 
18Z AVIATION DISCUSSION.  
 
 
   
KEY MESSAGES  
 
1) GUSTY WINDS OVER THE WEEKEND RESULTING ADVISORY LEVEL WINDS  
ACROSS PORTIONS OF SOUTHEAST CALIFORNIA AND LOCALLY ELEVATED FIRE  
DANGER ACROSS EASTERN ARIZONA  
 
2) NEAR NORMAL TEMPERATURES INTO EARLY NEXT WEEK BEFORE WE SEE  
A WARMING TREND AND ABOVE (ROUGHLY 5-10 DEGREES) NORMAL  
TEMPERATURES BY LATE NEXT WEEK  
 
3: WIDESPREAD MODERATE HEATRISK IS EXPECTED TO RETURN LATE NEXT  
WEEK AND POTENTIALLY CONTINUE THROUGH MEMORIAL DAY  
 
 
   
DISCUSSION  
 
WEATHER PATTERN OVERVIEW:  
BROAD UPPER LEVEL TROUGHING REMAINS IN PLACE ACROSS THE WESTERN  
U.S. WITH HEIGHTS ACROSS THE DESERT SOUTHWEST SLOWING RISING  
ALLOWING FOR SOME MODEST WARMING. UNDER SUNNY SKIES TODAY,  
TEMPERATURES ARE EXPECTED REACH INTO THE LOWER 90S TO AROUND 95  
DEGREES, OR RIGHT AROUND SEASONAL NORMALS.  
 
THE NEXT WEATHER SYSTEM THAT WILL IMPACT OUR REGION IS CURRENTLY  
OFF THE COAST OF BRITISH COLUMBIA, BUT IT IS FORECAST TO QUICKLY  
DIVE SOUTHEASTWARD OVER THE NEXT 24-48 HOURS REACHING CENTRAL  
CALIFORNIA AND WESTERN NEVADA BY LATE SATURDAY MORNING AND  
NORTHERN ARIZONA LATER SATURDAY EVENING. THE MAIN FORECAST  
CONCERN WITH THIS NEXT SYSTEM WILL BE THE INCREASE IN WINDS ACROSS  
THE REGION STARTING SATURDAY AFTERNOON AND LASTING INTO SATURDAY  
NIGHT. WIND ADVISORIES HAVE BEEN ISSUED FOR THE WESTERN HALF OF  
IMPERIAL CO. FOR THIS TIME WITH GUSTS IN EXCESS OF 40 MPH INTO THE  
IMPERIAL VALLEY WHICH IS LIKELY TO AT LEAST BRING SOME LOFTED  
DUST. ELSEWHERE ACROSS THE AREA, WINDS SATURDAY AFTERNOON AND  
EARLY EVENING ARE LIKELY TO GUST BETWEEN 20-30 MPH AT TIMES,  
ESPECIALLY ACROSS THE HIGHER TERRAIN.  
 
THE SATURDAY DISTURBANCE IS EXPECTED TO SHIFT NORTHEASTWARD OUT OF  
OUR REGION SUNDAY MORNING, BUT THERE WILL BE ANOTHER ONE QUICKLY  
FOLLOWING IN ITS WAKE MOVING SOUTHWARD ACROSS THE GREAT BASIN  
SUNDAY BEFORE LIKELY REACHING NORTHERN ARIZONA BY EARLY MONDAY.  
THE GRADIENT WILL STAY COMPACT ENOUGH ON SUNDAY TO PROVIDE FOR  
ANOTHER BREEZY DAY, BUT TO A LESSER DEGREE COMPARED TO SATURDAY.  
MODESTLY COOLER AIR WILL ALSO SPREAD INTO THE AREA SATURDAY NIGHT  
INTO SUNDAY, LOWERING HIGHS SUNDAY TO BETWEEN 85-90 DEGREES. THERE  
WILL ALSO BE A MINOR INFLUX OF LOWER LEVEL MOISTURE INTO OUR AREA  
ON SUNDAY, LASTING THROUGH THE FIRST PART OF MONDAY. DESPITE THIS  
INCREASE IN MOISTURE, THE BULK OF THE SYSTEM ENERGY IS EXPECTED TO  
STAY WELL TO OUR NORTH WITH ANY SHOWER CHANCES LIKELY CONFINED TO  
THE ARIZONA HIGH COUNTRY FOR SUNDAY AND MONDAY. MONDAY SHOULD  
ALSO BRING SOME INCREASED NORTHERLY BREEZINESS FOCUSED DOWN THE  
LOWER CO RIVER VALLEY AS DRIER AIR BEGINS SPREAD INTO THE AREA  
FROM THE NORTH. ENSEMBLE GUIDANCE AGREES THIS SECOND SYSTEM WILL  
EJECT TO THE EAST NORTHEAST BY MONDAY NIGHT WITH UPPER LEVEL  
RIDGING BEGINNING TO SPREAD IN FROM THE WEST.  
 
AS THE UPPER LEVEL RIDGE GRADUALLY SETTLES OVER THE DESERT  
SOUTHWEST DURING THE MIDDLE PART OF NEXT WEEK, WE ARE EXPECTING  
TO SEE A RETURN OF HOT TEMPERATURES AND HIGHS LIKELY REACHING OR  
TOPPING 100 DEGREES AS EARLY AS NEXT WEDNESDAY. THE LARGE SCALE  
WEATHER PATTERN IS EXPECTED TO SUPPORT KEEPING THE RIDGE OVER THE  
SOUTHWESTERN U.S. FOR SEVERAL DAYS AND LIKELY THROUGH NEXT  
WEEKEND. THERE ARE STILL SOME MODEL DIFFERENCES WITH THE FORECAST  
H5 HEIGHTS, BUT FOR NOW IT STILL LOOKS LIKE THE PEAK OF THE RIDGE  
MAY BE AROUND NEXT FRIDAY WITH SOME POTENTIAL MINOR FLATTENING OF  
THE RIDGE OVER MEMORIAL DAY WEEKEND. THE LATEST NBM FORECAST  
TEMPERATURES ARE VERY SIMILAR TO WHAT WE HAVE SEEN OVER THE PAST  
COUPLE OF RUNS WITH HIGHS PEAKING AT OR JUST ABOVE 105 DEGREES ON  
THURSDAY AND/OR FRIDAY, BUT WITH A SLIGHT LOWERING OF TEMPERATURES  
OVER MEMORIAL DAY WEEKEND. EITHER WAY, GUIDANCE CONTINUES TO SHOW  
MODERATE HEATRISK DEVELOPING BY NEXT WEDNESDAY OR THURSDAY.  
 
FORECAST CONFIDENCE & DEVIATIONS:  
 
CONFIDENCE IN TEMPERATURE FORECASTS REMAINS VERY GOOD THROUGH  
SATURDAY WITH A BIT LOWER CONFIDENCE GOING INTO NEXT WEEK,  
ESPECIALLY MONDAY, AS THE SECOND DISTURBANCE PASSES ACROSS  
NORTHERN PORTIONS OF THE REGION. IF THE SYSTEM ENDS UP DIGGING  
FARTHER SOUTH INTO ARIZONA, WE ARE MORE LIKELY TO SEE HIGHS  
CLOSER TO SUNDAY'S COMPARED TO SOME SLIGHT WARMING THE CURRENT NBM  
FAVORS. KEEPING IN LINE WITH PREVIOUS FORECAST PACKAGES,  
CONTINUED TO ADJUST THE WINDS HIGHER OVER THE WEEKEND, FOCUSED  
MORE OVER SOUTHEAST CALIFORNIA. FORECAST CONFIDENCE FOR THE HOTTER  
TEMPERATURES DURING THE LATTER HALF OF THE FORECAST PERIOD  
REMAINS GOOD, BUT SOME CHANGES TO THE TEMPERATURES (MAYBE A 1-3  
DEGREES HIGHER) MAY EVENTUALLY OCCUR, ESPECIALLY OVER THE MEMORIAL  
DAY WEEKEND.  
 
 
   
AVIATION  
UPDATED AT 1722Z.  
 
SOUTH CENTRAL ARIZONA INCLUDING KPHX, KIWA, KSDL, KDVT:  
 
NO AVIATION WEATHER CONCERNS ARE ANTICIPATED THROUGH THE FORECAST  
PERIOD. TYPICAL DIURNAL TRENDS WILL BE COMMON AT ALL TERMINALS,  
WITH THE EXCEPTION OF A MORE NW'RLY COMPONENT THIS EVENING.  
SPEEDS WILL REMAIN AT OR BELOW 8 KTS THROUGH THIS AFTERNOON, BUT  
INTERMITTENT GUSTS INTO THE TEENS WILL BE POSSIBLE AT THE PHOENIX  
THIS AFTERNOON INTO THE EVENING. MOSTLY CLEAR SKIES WILL PREVAIL  
OVER THE REGION.  
 
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH:  
 
NO AVIATION WEATHER CONCERNS ARE ANTICIPATED THROUGH THE FORECAST  
PERIOD. KIPL WILL BE E'RLY THROUGH THIS AFTERNOON, GOING W'RLY BY  
TONIGHT. KBLH WILL BE PREDOMINANTLY S'RLY. WINDS AT BOTH TERMINALS  
WILL GENERALLY BE AOB 10KTS, BUT LOOK TO INCREASE NEAR THE END OF  
THE TAF PERIOD, ESPECIALLY AT KBLH WITH SPEEDS INCREASING INTO  
THE TEENS. MOSTLY CLEAR SKIES WILL PREVAIL OVER THE REGION.  
 
 
   
FIRE WEATHER  
 
TODAY WILL BRING ANOTHER DAY OF SEASONABLY DRY CONDITIONS WITH  
LIGHT WINDS BEFORE WIND SPEEDS INCREASE MARKEDLY SATURDAY  
RESULTING IN AN ELEVATED FIRE DANGER ACROSS THE EASTERN  
DISTRICTS. MINRHS WILL REACH 10-15% TODAY AND SATURDAY ACROSS THE  
EASTERN DISTRICTS WITH READINGS ACROSS THE WESTERN DISTRICTS  
IMPROVING TO 20-25% SATURDAY. OVERNIGHT RECOVERY WILL BE FAIR TO  
POOR WITH READINGS BETWEEN 20-30% OVER THE EASTERN DISTRICTS AND  
30-50% OVER THE WESTERN DISTRICTS. WIND GUSTS OF 20-30 MPH WILL  
BE COMMON SATURDAY AFTERNOON WITH LOCALIZED STRONGER SPEEDS  
ACROSS THE WESTERN DISTRICTS. VERY WARM AND DRY WEATHER WILL  
RETURN DURING THE MIDDLE OF NEXT WEEK, HOWEVER WIND SPEEDS WILL BE  
MUCH WEAKER AS HIGH PRESSURE STARTS BUILDING INTO THE REGION.  
 
 
   
PSR WATCHES/WARNINGS/ADVISORIES  
 
AZ...NONE.  
CA...WIND ADVISORY FROM 2 PM SATURDAY TO 7 AM PDT SUNDAY FOR CAZ562.  
 
WIND ADVISORY FROM 4 PM SATURDAY TO 2 AM PDT SUNDAY FOR CAZ563-  
566-567.  
 
 
 
 
 
DISCUSSION...KUHLMAN  
AVIATION...RYAN  
FIRE WEATHER...KUHLMAN  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab AZ Page
The Nexlab CA Page
Main Text Page