377  
FXUS65 KTWC 092016  
AFDTWC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TUCSON AZ  
116 PM MST SUN AUG 9 2026  
   
SYNOPSIS  
EXPECT DAILY CHANCES OF SHOWERS AND THUNDERSTORMS  
MUCH OF THIS WEEK. WHILE THERE WILL BE DAY TO DAY VARIABILITY,  
MONDAY AND WEDNESDAY LOOK TO BE THE MOST ACTIVE DAYS. STORM COVERAGE  
WILL FRIDAY THROUGH NEXT WEEKEND. HIGH TEMPERATURES THIS AFTERNOON  
WILL RUN 5 TO 8 DEGREES ABOVE NORMAL, LOWERING TO NEAR NORMAL MONDAY  
AND TUESDAY WITH ADDITIONAL LOWERING TO AROUND 3 TO 6 DEGREES BELOW  
NORMAL WEDNESDAY AND THURSDAY BEFORE TEMPERATURES WARM AGAIN.  
 
 
   
DISCUSSION  
VISIBLE SATELLITE IMAGERY SHOWS CUMULUS CLOUD  
DEVELOPMENT THIS AFTERNOON ACROSS THE HIGHER TERRAIN OF SOUTHEAST  
ARIZONA. THE AREA IS UNDER EASTERLY FLOW ALOFT WITH MID/UPPER LEVEL  
HIGH NEAR THE FOUR CORNERS. STILL PLENTY OF MOISTURE FOR MUCH OF  
SOUTHEAST ARIZONA WITH PWAT AROUND 1 TO 1.5 INCHES, HIGHEST VALUES  
WEST. COCHISE COUNTY PWAT IS A BIT LOWER IN THE 0.7 TO 0.9 INCH  
RANGE AND THAT AREA WILL STRUGGLE MOST WITH CONVECTION THIS  
AFTERNOON INTO EVENING. CAMS ARE SHOWING TWO PRIMARY AREAS OF STORMS  
DEVELOPING THIS AFTERNOON, THE FIRST BEING SOUTH TO SOUTHWEST OF  
TUCSON CLOSE TO THE INT'L BORDER AND ANOTHER AREA MOVING OFF THE  
WHITE MOUNTAINS WITH STORM MOVEMENT TODAY TOWARDS THE WEST. GIVEN  
THE AMPLE SURFACE HEATING, ELEVATED DCAPE VALUES WILL SUPPORT GUSTY  
WINDS IN EXCESS OF 50 MPH WITH THE STRONGEST STORMS. IN FACT, THE  
HREF HAS AN AREA OF 10% 40-KM NEIGHBORHOOD PROBABILITY OF 50 KTS  
FROM TUCSON WESTWARD WITH A SMALLER AREA OF 30 PERCENT OVER CENTRAL  
AND WESTERN PIMA COUNTY. THESE STRONG WINDS WILL ALSO RESULT IN  
AREAS OF BLOWING DUST DUE TO STRONG OUTFLOWS. IN ADDITION TO THE  
GUSTY WINDS, A FEW STORMS MAY CLUSTER WEST OF TUCSON RESULTING IN  
ISOLATED FLASH FLOODING POTENTIAL INTO THE EVENING HOURS.  
 
MONDAY IS SHAPING UP TO BE A BIT MORE ACTIVE THAN TODAY AS EASTERLY  
FLOW ALOFT CONTINUES WITH PWAT VALUES TICKING UP SLIGHTLY COMPARED  
TO TODAY AND MODEST MID/UPPER LEVEL SUPPORT FOR STORMS. THIS WILL  
RESULT IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS FOR MOST OF  
SOUTHEAST ARIZONA, WITH THE HIGHEST CHANCES FROM TUCSON WESTWARD.  
WPC HAS HIGHLIGHTED THE AREA IN A SLGT RISK OF EXCESSIVE RAINFALL  
AND THAT LOOKS GOOD. HREF HAS A WIDESPREAD AREA OF GREATER THAN 50%  
40-KM NEIGHBORHOOD PROBABILITY OF 3-HR QPF OF 1 INCH OR GREATER.  
WHILE THERE IS STILL SOME UNCERTAINTY ON STORM MODE FOR MONDAY, AND  
WHETHER STORMS STAY MORE DISCRETE OR BECOME MORE CLUSTERED RESULTING  
IN HEAVIER RAIN POTENTIAL ESPECIALLY INTO THE EVENING, FELT IT WAS  
PRUDENT TO HIGHLIGHT THE POTENTIAL FOR HEAVY RAIN BY HOISTING A  
FLASH FLOOD WATCH FROM TUCSON AREA WESTWARD FROM 2 PM TO 10 PM. IN  
ADDITION TO THE FLASH FLOOD THREAT, SEVERE WINDS WILL ALSO BE A  
THREAT WITH CONSIDERABLE DCAPE AND EVEN AROUND 20-30 KTS OF 0-6KM  
BULK SHEAR BRINING THE POTENTIAL FOR SMALL HAIL AS WELL. GIVEN THE  
WIND POTENTIAL, ADDED IN AREAS OF BLOWING DUST NORTH AND WEST OF  
TUCSON INTO THE FORECAST.  
 
THE ACTIVE PATTERN WILL PERSIST TUESDAY AND WEDNESDAY WITH WEDNESDAY  
STILL LOOKING LIKE A MORE ACTIVE DAY AS A DISTURBANCE IN NORTHERN  
SONORA MAY HELP AID STORM DEVELOPMENT THEN. THEREAFTER, AS SOUTHWEST  
FLOW MOVES IN STARTING THURSDAY, THAT WILL SHIFT STORM CHANCES FROM  
ABOUT THE TUCSON AREA EASTWARD THURSDAY, THEN GENERALLY NEAR THE NM  
BORDER FRIDAY THROUGH NEXT WEEKEND WITH MOST OF SE ARIZONA REMAINING  
DRY THOSE DAYS.  
 
TEMPERATURES WILL LOWER TO NEAR NORMAL LEVELS MONDAY AND TUESDAY,  
THEN TO ABOUT 3 TO 6 DEGREES BELOW NORMAL WEDNESDAY AND THURSDAY,  
WITH WARMING THEREAFTER TO ABOVE NORMAL VALUES FOR NEXT WEEKEND.  
 
 
   
AVIATION  
VALID THRU 11/00Z.  
ISOLD-WDLY SCTD -SHRA/-TSRA WITH CLOUDS 8-12K FT AGL, MAINLY WEST OF  
A KSAD-KOLS LINE INTO THIS EVENING AND THEN AGAIN MONDAY AFTERNOON  
FOR MUCH OF SE ARIZONA. GUSTY ERRATIC WINDS OF 35-45 KTS POSSIBLE  
WITH ANY THUNDERSTORM. OUTSIDE OF STORMS SFC WINDS WLY/NWLY AT 8-12  
KTS WITH OCCASIONAL AFTERNOON GUSTS TO 20 KTS THIS AFTERNOON AND  
EVENING. SFC WINDS LIGHT AND TERRAIN DRIVEN AFTER 10/06Z THRU 10/18Z  
WITH WLY/NWLY WINDS RESUMING THEREAFTER. AVIATION DISCUSSION NOT  
UPDATED FOR TAF AMENDMENTS.  
 
 
   
FIRE WEATHER  
EXPECT DAILY AFTERNOON AND EVENING SHOWERS AND  
THUNDERSTORMS THROUGH THURSDAY WITH LESS COVERAGE FRIDAY INTO N EXT  
WEEKEND. MINIMUM RELATIVE HUMIDITY WILL BE 20-40 PERCENT MONDAY  
THROUGH THURSDAY LOWERING TO AROUND 15-30 PERCENT THEREAFTER.  
TEMPERATURES WILL BE NEAR NORMAL THROUGH TUESDAY, DROPPING TO BELOW  
NORMAL WEDNESDAY AND THURSDAY, THEN WARMING AGAIN NEXT WEEKEND.  
OUTSIDE OF THUNDERSTORMS, WINDS TERRAIN DRIVEN TO AROUND 10 MPH WITH  
OCCASIONAL AFTERNOON GUSTS TO 20 MPH.  
 
 
   
TWC WATCHES/WARNINGS/ADVISORIES  
 
FLOOD WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR  
AZZ501>506-514-515.  
 
 
 
 
 
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