702  
FXUS65 KTWC 261700  
AFDTWC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TUCSON AZ  
1000 AM MST THU JUN 26 2025  
   
SYNOPSIS  
AFTERNOON AND EVENING CHANCES FOR SHOWERS AND  
THUNDERSTORMS ARE POSSIBLE DAILY THROUGH FRIDAY IN EASTERN  
LOCATIONS, MAINLY CLOSER TO THE NEW MEXICO BORDER. TEMPERATURES  
BECOME HOTTER THIS WEEKEND AS CONDITIONS DRY OUT. MOISTURE IS  
EXPECTED TO INCREASE NEXT WEEK AND LIKELY BRING THE START TO THE  
MONSOON SEASON.  
 
 
   
UPDATE  
THE SKY WAS SUNNY TO PARTLY CLOUDY ACROSS SOUTHEAST  
ARIZONA THIS MORNING. GOES-19 PW IMAGERY SHOWED VALUES BETWEEN  
0.80" AND 1" ALONG THE AZ/NM BORDER. THIS AREA WILL HAVE A 10-30%  
CHANCE OF STORMS THIS AFTERNOON. OTHERWISE HIGH TEMPERATURES WILL  
BE NEAR NORMAL. SEE DISCUSSION BELOW FOR FURTHER DETAILS IN THE  
7-DAY FORECAST.  
 
 
   
DISCUSSION  
WATER VAPOR AND SATELLITE DERIVED MOISTURE  
PRODUCTS THIS MORNING SHOW AN EASTWARD EXPANSION OF DRY AIR INTO  
WESTERN GRAHAM AND COCHISE COUNTIES. THIS HAS DROPPED FORECAST  
THUNDERSTORM COVERAGE TODAY TO AN AREA GENERALLY NEAR AND EAST OF  
A LINE FROM THE WHITE MOUNTAINS THROUGH SAFFORD, WILLCOX, AND  
SIERRA VISTA. WITH SATELLITE DERIVED PRECIPITABLE WATER VALUES  
GENERALLY NEAR OR BELOW ONE INCH AND FORECAST CAPE VALUES ON THE  
WEAK SIDE IN THIS AREA, STORM COVERAGE AND STRENGTH SHOULD BE LOW.  
 
FRIDAY SHOULD SEE A MARGINALLY BETTER ENVIRONMENT IN EASTERN  
LOCATIONS THAN TODAY, BUT OTHERWISE A SIMILAR STORM STRENGTH  
OUTLOOK WILL BE IN STORE. 00Z GUIDANCE DOES TRY TO BRING IN WEAK  
MOISTURE INTO SOUTHERN PIMA AND SANTA CRUZ COUNTIES FRIDAY,  
HOWEVER THIS DOESN'T LOOK LIKE A STRONG ENOUGH PUSH AT THIS MOMENT  
TO ADD NOTABLE THUNDERSTORM CHANCES.  
 
FROM THIS WEEKEND INTO EARLY NEXT WEEK AN UPPER RIDGE IS EXPECTED  
TO BECOME CENTERED OVER THE FOUR CORNERS. BY MONDAY THIS RIDGE  
WILL LIKELY HAVE BECOME AMPLIFIED THROUGH THE PACIFIC NORTHWEST  
AND NORTHERN ROCKIES. NAEFS GUIDANCE SHOWS 700MB TEMPERATURES OVER  
ARIZONA AROUND THE 90TH CLIMATOLOGICAL PERCENTILE FOR THIS TIME  
OF YEAR, HIGHLIGHTING THE HEAT POTENTIAL. CURRENT FORECAST HIGHS  
FOR SOUTHEASTERN ARIZONA DESERT LOCATIONS ON MONDAY RUN FROM 108  
TO 112.  
 
THIS RIDGE ORIENTATION NEXT WEEK WILL ADDITIONALLY FAVOR THE  
INCREASE IN MOISTURE NEEDED TO START THE MONSOON SEASON. AS  
PREVIOUSLY DISCUSSED THE CLIMATE PREDICTION CENTER HAS HIGHLIGHTED  
SOUTHERN ARIZONA FOR A HIGH RISK OF HEAVY RAINFALL AND FLASH  
FLOODING DURING THE SECOND HALF OF THE WEEK, WHICH IS WHEN  
ENSEMBLE MODELS HAVE HEAVILY FAVORED RICH MOISTURE TO SET IN. IN  
THE INITIAL MOISTURE PUSH HOWEVER THERE WILL STILL BE  
OPPORTUNITIES FOR THUNDERSTORM IMPACTS INCLUDING STRONG WIND  
GUSTS, BLOWING DUST, AND LIGHTNING AS EARLY AS MONDAY AS THE  
INCOMING MOISTURE INTERACTS WITH THE HOT AND INITIALLY DRY  
ANTECEDENT ATMOSPHERE.  
 
 
   
AVIATION  
VALID THROUGH 27/12Z.  
FEW CLOUDS AT 10K FEET, OTHERWISE SKC THROUGH 26/18Z. FEW-SCT  
CUMULUS AT 10K FEET WITH ISOLATED TO SCATTERED SHOWERS AND  
THUNDERSTORMS MAINLY NEAR AND EAST OF A KSAD- KFHU LINE AFTER  
26/18Z, DIMINISHING AFTER 27/03Z. ISOLATED GUSTS UP TO 40 KTS WITH  
STRONGER CELLS. OTHERWISE WINDS LIGHT AND UNDER 12 KTS WITH AN  
OCCASIONAL AFTERNOON GUST UP TO 20 KTS. AVIATION DISCUSSION NOT  
UPDATED FOR TAF AMENDMENTS.  
 
 
   
FIRE WEATHER  
CHANCES FOR ISOLATED TO SCATTERED SHOWERS AND  
THUNDERSTORMS TODAY AND TOMORROW EAST OF TUCSON. MINIMUM RELATIVE  
HUMIDITIES FROM 10 TO 20 PERCENT TODAY AND TOMORROW, WITH A DRYING  
AND WARMING TREND THIS WEEKEND. WINDS GENERALLY LIGHT AND UNDER  
15 MPH WITH ISOLATED GUSTS UP TO 45 MPH UNDER ANY THUNDERSTORM  
THROUGH FRIDAY. MOISTURE SHOULD BEGIN TO ARRIVE NEXT WEEK AND  
BRING A START TO THE MONSOON SEASON ACROSS SOUTHEASTERN ARIZONA.  
 
 
   
TWC WATCHES/WARNINGS/ADVISORIES  
NONE.  
 
 
 
 
 
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