382  
FXUS63 KDMX 032328  
AFDDMX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DES MOINES IA  
628 PM CDT THU SEP 3 2026  
 
...UPDATED FOR THE 00Z AVIATION DISCUSSION...  
   
KEY MESSAGES
 
 
- SCATTERED SHOWERS AND THUNDERSTORMS ACROSS NORTHERN IOWA THIS  
AFTERNOON WILL GRADUALLY DIMINISH INTO THE EVENING HOURS.  
GUSTY WINDS ARE POSSIBLE BUT MORE ROBUST SEVERE STORMS ARE  
NOT EXPECTED.  
 
- ADDITIONAL SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP IN  
NORTHEAST IOWA EARLY FRIDAY MORNING AND LASTING INTO THE  
AFTERNOON.  
 
- HEAT AND HUMIDITY CONTINUES INTO THIS WEEKEND. THE HEAT  
ADVISORY HAS BEEN EXTENDED THROUGH SATURDAY EVENING AND  
EXPANDED A ROW OF COUNTIES NORTH TO INCLUDE THE HIGHWAY 30  
CORRIDOR.  
 

 
   
SHORT TERM /THROUGH FRIDAY/
 
 
ISSUED AT 211 PM CDT THU SEP 3 2026  
 
SCATTERED SHOWERS AND THUNDERSTORMS HAVE PERSISTED ACROSS  
NORTHERN INTO CENTRAL IOWA INTO THIS AFTERNOON, FUELED IN PART  
BY A LOW LEVEL JET THAT HAS LASTED WELL BEYOND WHAT COULD BE  
CALLED "NOCTURNAL". THIS HAS FINALLY BEGUN TO FADE EARLY THIS  
AFTERNOON, BUT STORMS CONTINUE ALONG THE THETA E GRADIENT THAT  
IS DRAPED ACROSS NORTHERN IOWA. EXPECTATION IS FOR STORMS TO  
GRADUALLY TAPER OFF INTO THE EARLY EVENING HOURS, AS HAS BEEN  
THE CASE THE LAST FEW DAYS. WHILE DEWPOINTS ARE HIGH, SOME DRY  
AIR IS STILL IN PLACE IN THE LOW LEVELS OF SOUNDINGS AND COULD  
RESULT IN GUSTY WINDS WITH ANY COLLAPSING CELLS. THE  
PRECIPITATION ACROSS NORTHERN IOWA HAS CREATED MUCH COOLER  
TEMPERATURES IN RAIN-IMPACTED AREAS WITH TEMPERATURES IN THE  
MID 70S WHILE THE REST OF THE STATE HAS QUICKLY WARMED INTO THE  
UPPER 80S AND LOW 90S ALREADY THIS AFTERNOON. WITH DEWPOINTS IN  
THE 70S THIS HAS SENT THE HEAT INDEX INTO THE UPPER 90S TO LOW  
100S IN CENTRAL AND SOUTHERN IOWA.  
 
ONCE AGAIN EXPECT OVERNIGHT AND EARLY MORNING THUNDERSTORMS TO  
DEVELOPING IOWA, THIS TIME ASSOCIATED WITH A WEAK SHORTWAVE  
THAT WILL SLIDE ALONG THE THERMAL RIDGE FROM MINNESOTA INTO  
WISCONSIN AND INTO ILLINOIS ON FRIDAY. A FEW STRONGER STORMS ARE  
POSSIBLE WITH THE EXTRA FORCING ASSOCIATED WITH THE SHORTWAVE,  
HOWEVER THIS IS EXPECTED TO REMAIN MOSTLY EAST OF THE AREA.  
CONVECTION THAT TRAILS INTO PARTS OF NORTHEAST IOWA SHOULD BE  
AWAYS FROM THE BETTER FORCING WITH LESS OF A SEVERE THREAT.  
GUSTY WINDS WOULD BE THE PRIMARY CONCERN FOR ANY STRONGER CELLS  
THAT DO DEVELOP ON FRIDAY.  
 
WITH CONVECTION SHIFTED EAST THE HEAT AND HUMIDITY ON FRIDAY WILL BE  
ABLE TO SURGE FARTHER NORTH INTO THE STATE. AS SUCH, HAVE  
EXPANDED THE HEAT ADVISORY A ROW OF COUNTIES FARTHER NORTH TO  
INCLUDE THE HIGHWAY 30 CORRIDOR. HEAT INDICIES FROM 100-105 ARE  
POSSIBLE IN THE AFTERNOON. SIMILARLY ON SATURDAY, CONVECTION  
LOOKS TO REMAIN ON THE FRINGES OF THE STATE AND SO THE HEAT  
ADVISORY HAS ALSO BEEN EXTENDED IN TIME OUT THROUGH SATURDAY  
EVENING. AS WE THINK ABOUT THE UPCOMING HOLIDAY WEEKEND AND ANY  
OUTDOOR PLANS, BE SURE TO CONTINUE TO EXERCISE APPROPRIATE HEAT  
SAFETY MEASURES INCLUDING HYDRATING PROPERLY, TAKING BREAKS IN  
THE SHADE, AND AVOIDING STRENUOUS ACTIVITY.  
 

 
   
LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/
 
 
ISSUED AT 211 PM CDT THU SEP 3 2026  
 
A MORE ROBUST TROUGH WILL MOVE EAST ACROSS THE NORTHERN US FROM  
SUNDAY INTO EARLY NEXT WEEK. THIS WILL RENEW THE PERIODIC SCATTERED  
THUNDERSTORMS CHANCES EACH DAY WHILE ALSO HELPING TO SQUASH THE  
THERMAL RIDGE. WE WILL NOT SEE SUBSTANTIAL COOLING, HOWEVER  
TEMPERATURES SUNDAY INTO EARLY NEXT WEEK SHOULD BE AT LEAST A  
FEW DEGREES COOLER THAN WHAT WE HAVE SEEN THIS WEEK. THE RIDGE  
DOES LOOK TO REBUILD FOR THE MIDDLE TO END OF NEXT WEEK. HEAT  
AND HUMIDITY ALONG WITH CONTINUED SCATTERED THUNDERSTORM CHANCES  
LOOKS TO BE THE STORY FOR AT LEAST ANOTHER WEEK.  
 

 
   
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/
 
 
ISSUED AT 624 PM CDT THU SEP 3 2026  
 
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE PERIOD. ADDED IN  
A PROB30 GROUP FOR SHOWERS AT KMCW, ALTHOUGH MOST ACTIVITY,  
INCLUDING THUNDERSTORMS, LOOKS TO REMAIN MORE IN WISCONSIN AND  
MINNESOTA AT THIS TIME.  
 

 
   
DMX WATCHES/WARNINGS/ADVISORIES
 
 
HEAT ADVISORY FROM 1 PM FRIDAY TO 7 PM CDT SATURDAY FOR  
IAZ044>050.  
HEAT ADVISORY UNTIL 7 PM CDT SATURDAY FOR IAZ057>062-070>075-  
081>086-092>097.  
 

 
 

 
 
SHORT TERM...HAGENHOFF  
LONG TERM...HAGENHOFF  
AVIATION...JIMENEZ  
 
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