611  
FXUS65 KTWC 252142  
AFDTWC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TUCSON AZ  
242 PM MST MON AUG 25 2025  
   
SYNOPSIS  
EXPECT DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS  
WITH DAY TO DAY VARIABILITY ON COVERAGE AND INTENSITY THROUGH MID  
WEEK WITH A DRYING TREND LATER IN THE WEEK. ABOVE NORMAL  
TEMPERATURES THROUGH TODAY THEN TRENDING DOWN TO SLIGHTLY BELOW  
NORMAL TUESDAY THROUGH THURSDAY.  
 
 
   
UPDATE  
QUICK UPDATE TO EXTEND TIMING OF PINAL/EASTERN PORTIONS  
OF PIMA COUNTY BLOWING DUST ADVISORY UNTIL 7 PM MST. WARN-ON-  
FORECAST SYSTEM SEVERE WIND PROBABILITIES HAVE BEEN HIGHLIGHTING A  
STRONG TO SEVERE WIND POTENTIAL FROM NORTHWEST OF TUCSON THROUGH  
PINAL COUNTY FROM JUST BEFORE 23Z THROUGH AT LEAST 00Z THIS  
EVENING, POTENTIALLY LATCHING ON TO A RISK OF BLOWING DUST ALONG  
THE INTERSTATE 10 CORRIDOR. THAT SAID, CURRENT SATELLITE PICTURE  
DOES SHOW INCREASING ANVIL COVER THE TUCSON METRO, WHICH ADDS SOME  
UNCERTAINTY IN STRONGEST THUNDERSTORM POTENTIAL LATER THIS  
AFTERNOON AND EARLY EVENING. TO BE ON THE SAFE SIDE HOWEVER, THE  
CURRENT BLOWING DUST ADVISORY WAS EXTENDED IN TIME UNTIL 7 PM TO  
COVER THIS POTENTIAL AND SOMEWHAT LATER TIMING.  
 
 
   
PREV DISCUSSION  
/ISSUED 1231 PM MST MON AUG 25 2025/ SHOWERS  
AND THUNDERSTORMS ARE STARTING TO DEVELOP RIGHT ON SCHEDULE ACROSS  
SANTA CRUZ COUNTY. THE 18Z KTWC SOUNDING CAME IN WITH A PWAT OF  
1.43 INCHES AND MODEST INSTABILITY AND JUST A BIT OF A CAP TO WORK  
THROUGH. PWATS GENERALLY RANGE FROM 1.2 INCH TO 1.7 INCH RANGE  
FROM TUCSON WESTWARD, WHILE DRIER AIR IS HANGING ON EAST OF TUCSON  
ACROSS GRAHAM/GREENLEE/COCHISE COUNTIES WHERE PWATS ARE AROUND  
0.8 TO 1.2 INCHES. THE CONVECTION NOW DEVELOPING WILL QUICKLY  
EXPAND TO THE NORTH AND WEST THROUGH THE AFTERNOON. CONVECTION  
WILL BE AIDED BY DIVERGENCE OUT AHEAD OF AN UPPER LEVEL TROUGH  
OVER SONORA. MLCAPE VALUES OF 1000-1500 J/KG WITH DCAPE OF AROUND  
1000-1300 J/KG. WHILE INDIVIDUAL STORM MOTIONS WILL BE AROUND 15  
KTS TO THE WEST AND NORTHWEST, 20-25 KTS OF 0-6KM BULK SHEAR WILL  
HELP SUPPORT MULTI-CELLULAR STORMS AND DEVELOPMENT OF A LARGER  
COLD POOL CAPABLE OF PRODUCING STRONG OUTFLOW WINDS. AS ADDITIONAL  
MOISTURE CONTINUES TO FEED IN TODAY, FLASH FLOODING IS A THREAT  
AS WELL, ESPECIALLY WITH MERGING CELLS/CLUSTERS. A FLASH FLOOD  
WATCH FROM TUCSON WESTWARD AND A BLOWING DUST ADVISORY ARE IN  
EFFECT THIS AFTERNOON INTO EARLY EVENING. MEANWHILE, FOR  
GRAHAM/GREENLEE/COCHISE COUNTIES, GIVEN THE DRIER AIR MASS IN  
THOSE LOCALES, THUNDERSTORM ACTIVITY WILL NOT BE NEARLY AS  
WIDESPREAD. WHILE THE MAIN CLUSTER OF STORMS SHOULD EXIT OUR AREA  
THIS EVENING, WE CAN'T RULE OUT A FEW LINGERING SHOWERS OVERNIGHT.  
 
THE FLOW WILL BE MORE SOUTHERLY ON TUESDAY COMPARED TO TODAY WITH  
STILL SOME SEMBLANCE OF MID LEVEL TROUGHING JUST TO OUR SOUTH. IF  
THE FORECAST REMAINS ON TARGET FOR TODAY, MUCH OF THE CENTRAL AND  
WESTERN PORTIONS OF OUR FORECAST AREA WILL BE WORKED OVER WITH THE  
POTENTIAL FOR SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WHILE THE  
FOCUS FOR DEEPER CONVECTION WILL BE FROM TUCSON EASTWARD INTO  
GRAHAM/GREENLEE/COCHISE COUNTIES WHICH WON'T SEE AS MUCH ACTIVITY  
TODAY. TEMPERATURES WILL DROP TO AROUND 3 TO 6 DEGREES BELOW NORMAL  
TUESDAY.  
 
AS THE FLOW BECOMES MORE SOUTHWESTERLY WEDNESDAY WITH THE  
SUBTROPICAL HIGH SLIPPING TO OUR SOUTHEAST, THAT WILL PROMOTE A  
DRYING TREND COMPARED TO TODAY AND TUESDAY WITH CONTINED BELOW  
NORMAL TEMPERATURES. THIS SOUTHWEST FLOW WILL CONTINUE THURSDAY AND  
FRIDAY, THOUGH WE'LL HAVE TO WATCH FOR ANY ADDITIONAL MID LEVEL  
MOISTURE INCREASE OFF OF TS JULIETTE WELL TO THE WEST OF BAJA. THE  
BEST CHANCES FOR SHOWERS AND THUNDERSTORMS IS EXPECTED TO REMAIN TO  
THE SOUTH AND EAST OF TUCSON THURSDAY INTO THE WEEKEND. BY LATE IN  
THE WEEKEND, THE FLOW TRIES TO BECOME MORE SOUTHERLY TO  
SOUTHEASTERLY AGAIN AND THIS COULD HELP EXPAND PRECIPITATION CHANCES  
FURTHER WEST BUT CONFIDENCE IS LOW. TEMPERATURES WILL WARM BACK UP  
TO NEAR OR SLIGHTLY ABOVE NORMAL LEVELS FRIDAY THROUGH THE WEEKEND.  
 
 
   
AVIATION  
VALID THROUGH 27/00Z.  
SCT-BKN 9K-12K FT AGL. WIDELY SCATTERED SHRA/TSRA FROM KOLS/KTUS  
WESTWARD MOVING NW/W NOW THRU 26/03Z. EXPECT GUSTY AND ERRATIC WINDS  
WITH ANY TSRA OUTFLOW WITH POSSIBLE BLDU REDUCING VISIBILITIES TO  
1/4-1 MILE. SFC WINDS WILL GENERALLY BE E-SE LESS THAN 12 KTS FROM  
26/03Z THRU 26/19Z. OTHERWISE, SFC WINDS MAINLY WLY/NWLY WITH THE  
EXCEPTION OF LOCALES NEAR THE NM BORDER. AVIATION DISCUSSION NOT  
UPDATED FOR TAF AMENDMENTS.  
 
 
   
FIRE WEATHER  
EXPECT DAILY CHANCES FOR RAIN SHOWERS AND  
THUNDERSTORMS THROUGH MID WEEK WITH DIMINISHING CHANCES LATER IN THE  
WEEK INTO NEXT WEEKEND. TEMPERATURES WILL BE RUNNING NEAR TO  
SLIGHTLY BELOW NORMAL THIS WEEK. WINDS WILL GENERALLY REMAIN LESS  
THAN 15 MPH WITH THE AFTERNOON GUSTINESS THIS WEEK. MIN RHS WILL BE  
30-40 PERCENT IN THE LOW ELEVATIONS AND 40-60 PERCENT IN THE  
MOUNTAINS THROUGH THURSDAY THEN MIN RHS DROP TO 15-25 PERCENT IN THE  
LOW ELEVATIONS AND 20-35 PERCENT IN THE MOUNTAINS THROUGH THE  
WEEKEND.  
 
 
 
 
   
TWC WATCHES/WARNINGS/ADVISORIES  
 
BLOWING DUST ADVISORY UNTIL 7 PM MST THIS EVENING FOR AZZ502-504-  
505.  
 
FLOOD WATCH UNTIL 7 PM MST THIS EVENING FOR AZZ501>505-514-515.  
 
BLOWING DUST ADVISORY UNTIL 7 PM MST THIS EVENING FOR AZZ501.  
 
 
 
 
 
UPDATE...EDWARDS  
 
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