665  
FXUS65 KTWC 122014  
AFDTWC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TUCSON AZ  
114 PM MST SAT SEP 12 2026  
   
SYNOPSIS
 
A MORE TYPICAL ISOLATED TO SCATTERED COVERAGE OF STORMS  
IS FORECAST THIS WEEKEND INTO NEXT WEEK. DAILY HIGH TEMPERATURES  
WILL FLUCTUATE BETWEEN NEAR NORMAL AND A FEW DEGREES BELOW  
NORMAL.  
 

 
   
DISCUSSION
 
SCATTERED STORMS ALREADY ONGOING AND CONTINUE TO FILL  
INTO THE TUCSON METRO WHICH IS NO SURPRISE GIVEN THE MOISTURE  
PROFILE IN PLACE TODAY IN CONJUNCTION WITH SUFFICIENT INSTABILITY.  
WE'LL MAINLY BE MONITORING FOR HEAVY RAINFALL THIS AFTERNOON AS  
SCATTERED STORMS WITH FREQUENT LIGHTNING CONTINUE TO EVOLVE, BUT  
CAN'T RULE OUT STRONG GUSTY OUTFLOW WINDS. WITH VERY WEAK FLOW IN  
THE ATMOSPHERE, THE STORMS THAT DO FORM HAVE THE POTENTIAL TO DUMP  
AN IMPACTFUL AMOUNT OF RAIN OVER THE SAME SPOT RESULTING IN WATER  
FLOWING IN NORMALLY DRY WASHES AND LOW WATER CROSSINGS BECOMING  
INUNDATED WITH SWIFT MOVING WATER. HREF DEPICTS A SLIGHT CHANCE  
(10%) FOR RAINFALL TOTALS EXCEEDING 3 INCHES. IF STORMS DO GRADUALLY  
EVOLVE INTO THE TUCSON METRO PROPER, WE COULD SEE URBAN STREET  
FLOODING WITH PONDING OF WATER ON ROADWAYS AND IN POOR DRAINAGE  
AREAS. THIS WEEKEND CHANCES FOR ISOLATED TO SCATTERED STORMS  
CONTINUES, AGAIN WITH THE MOISTURE WE HAVE IN PLACE THE PRIMARY  
CONCERN CONTINUES TO LEAN TOWARD HEAVY RAINFALL AND LOCALIZED  
FLASH FLOODING.  
 
MONDAY STILL LOOKS TO BE A BIT MORE ACTIVE AS A WEAK DISTURBANCE  
MOVES ACROSS SOUTHEAST ARIZONA. COMBINED WITH THE ADDITIONAL  
MOISTURE WE HAVE IN PLACE, ANY LIFTING MECHANISM CAN HELP PROVIDE  
CONFIDENCE IN A HEAVY RAINFALL EVENT. QPF CONTINUES TO TREND UP  
WITH WPC PLACING PORTIONS OF THE FORECAST AREA UNDER SLIGHT  
RISK FOR EXCESSIVE RAINFALL WITH THE POTENTIAL FOR STRONGER  
STORMS PRODUCING RAINFALL RATES OF 1-2"/HR LEADING TO THE  
INCREASED RISK OF LOCALIZED FLASH FLOODING. TIME WILL TELL AS  
ITS DIFFICULT TO TIME DISTURBANCES THIS FAR OUT.  
 

 
   
AVIATION
 
VALID THRU 14/00Z.  
SCT SHRA/TSRA THRU 13/04Z. SFC WINDS WLY/NWLY 6-10 KTS THRU 13/05  
BECOMING TERRAIN DRIVEN AND LESS THAN 10 KTS THEREAFTER. TOMORROW,  
ISOLD-SCT SHRA/TSRA AFT 13/17Z. SFC WINDS WLY/NWLY AT 6-10 KTS.  
VISIBILITY 1-3 SM POSSIBLE IN TSRA. AVIATION DISCUSSION NOT  
UPDATED FOR TAF AMENDMENTS.  
 

 
   
FIRE WEATHER
 
A TYPICAL ISOLATED TO SCATTERED COVERAGE OF STORMS  
IS FORECAST THIS WEEKEND INTO NEXT WEEK. HIGH TEMPERATURES WILL WILL  
FLUCTUATE BETWEEN NEAR NORMAL AND A FEW DEGREES BELOW NORMAL.  
MIN RH VALUES MAINLY 20 TO 45 PERCENT IN THE VALLEYS AND 35 TO 65  
PERCENT IN THE MOUNTAINS OVER THE NEXT WEEK. RH RECOVERIES WILL  
CONTINUE TO BE EXCELLENT OVERNIGHT. WINDS WILL GENERALLY REMAIN LESS  
THAN 15 MPH AND TERRAIN DRIVEN. GUSTY AND ERRATIC WINDS WILL  
ACCOMPANY THUNDERSTORMS.  
 

 
   
TWC WATCHES/WARNINGS/ADVISORIES
 
NONE.  
 

 
 

 
 
DVS  
 
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