750  
FXUS63 KDVN 080851  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
351 AM CDT FRI AUG 8 2025  
   
KEY MESSAGES
 
 
- HOT AND HUMID CONDITIONS ARE EXPECTED THROUGH SATURDAY. A HEAT  
ADVISORY IS IN EFFECT AREA-WIDE TODAY FOR HEAT INDICES OF  
100-105 DEGREES. ADDITIONAL HEAT HEADLINES MAY BE NEEDED ON  
SATURDAY FOR PARTS OF THE AREA.  
 
- THERE IS AN INCREASING THREAT FOR PERIODS OF VERY HEAVY  
RAINFALL FROM SATURDAY AFTERNOON INTO SUNDAY, WHICH MAY LEAD  
TO AREAS OF FLASH FLOODING AND TO SIGNIFICANT RISES ON AREA  
TRIBUTARY RIVERS.  
 

 
   
SHORT TERM /THROUGH SATURDAY NIGHT/
 
 
ISSUED AT 330 AM CDT FRI AUG 8 2025  
 
TODAY  
 
SPC MESOANALYSIS HAD A BROAD AREA OF LOW PRESSURE OVER THE  
NORTHERN TO CENTRAL PLAINS, AND SUBTLE RIDGING ALOFT FURTHER  
DOWNSTREAM OVER THE MID/UPPER MISSISSIPPI VALLEY AND WESTERN  
GREAT LAKES REGION. A WARM AND HUMID AIR MASS WAS IN PLACE  
ACROSS MUCH OF THE MIDWEST WITH LOCAL DEWPOINTS ACROSS EASTERN  
IOWA AND NORTHWEST ILLINOIS IN THE UPPER 60S/LOWER 70S. BREEZY  
SOUTHERLY WINDS ARE EXPECTED TODAY, AND COMBINED WITH PLENTY OF  
SUNSHINE, WILL LEAD TO HIGHS IN THE UPPER 80S TO LOWER 90S.  
PEAK HEAT INDICES BETWEEN 100 TO 105 DEGREES ARE EXPECTED  
ACROSS THE OUTLOOK AREA, WITH THE HIGHEST VALUES SOUTH OF  
HIGHWAY 30. DECIDED TO ADD IN THE IOWA COUNTIES ALONG HIGHWAY 20  
TO THE HEAT HEADLINE AS WELL.  
 
NBM DEWPOINTS MAY BE A LITTLE TOO HIGH WITH POCKETS OF UPPER  
70S THIS AFTERNOON AND EVENING. SO CAPPED TDS IN THE LOW TO MID  
70S WITH EVAPOTRANSPIRATION FROM THE CROPS NOT EXPECTED TO BE AS  
PROLIFIC AS IT WAS IN LATE JULY. OVERALL, EXPECT A HOT AND DRY  
DAY WITH THE MID-LEVEL RIDGE OVERHEAD AND THE LACK OF A LOW-  
LEVEL TRIGGER PREVENTING STORM DEVELOPMENT.  
 
SATURDAY THROUGH SATURDAY NIGHT  
 
CONTINUED HEAT AND HUMIDITY: ANOTHER HOT AND HUMID DAY IS  
ANTICIPATED BUT WITH LOWER CONFIDENCE ON REACHING ADVISORY  
CRITERIA DUE TO POTENTIAL FOR OCCASIONAL CLOUD COVER AND  
DEVELOPMENT OF SCATTERED SHOWERS AND STORMS THROUGHOUT THE DAY.  
AREAS THAT CAN AVOID THE RAIN THROUGH MID/LATE AFTERNOON HAVE  
THE BEST CHANCE TO REACH HEAT INDICES AROUND 100 DEGREES. RIGHT  
NOW THIS IS FAVORED ROUGHLY ACROSS THE SOUTHEAST HALF OR SO OF  
THE AREA (ALONG AND SOUTH OF A LINE FROM STERLING, IL TO THE  
QUAD CITIES TOWARD FAIRFIELD, IA).  
 
FLASH FLOODING POTENTIAL: THE SOUTHERN EXTENT OF A DEEP UPPER  
TROUGH WILL SHIFT INTO THE MIDWEST AS THE RIDGE BEGINS TO BREAK  
DOWN AND SLIDE OFF TO THE EAST. AT THE SURFACE, A WEAK BUT  
CONVECTIVELY ACTIVE BOUNDARY IS FORECAST TO DRIFT INTO EASTERN  
IOWA AND NORTHWEST ILLINOIS DURING THE AFTERNOON AND EVENING  
BEFORE ESSENTIALLY STALLING OUT THROUGH SATURDAY NIGHT INTO  
SUNDAY. THIS SETUP COULD RESULT IN AREAS OF VERY HEAVY RAINFALL  
DUE TO SLOW MOVING AND TRAINING CONVECTION (REPEATED ROUNDS OF  
STORMS). THE POTENTIAL FOR HEAVY RAINFALL IS FURTHER SUPPORTED  
BY VERY HIGH PWATS UPWARDS OF 2 - 2.3" (~99 PERCENTILE PER ECMWF  
ENSEMBLE SA TABLE) AND HIGH FREEZING LEVELS UP TO 16 KFT  
LEADING TO EFFICIENT WARM-RAIN PROCESS. ADDITIONALLY, THE FORECAST  
MEAN 850-300MB FLOW IS LARGELY PARALLEL TO THE AFOREMENTIONED  
BOUNDARY, WHICH WOULD FAVOR REPEATED ROUNDS OF STORMS AND  
EXCESSIVE RAINFALL FOR SOME AREAS. A FLOOD WATCH MAY EVENTUALLY  
BE NEEDED FOR SATURDAY PM INTO SUNDAY WITH THE POTENTIAL FOR  
PEAK HOURLY RAIN RATES BETWEEN 1-3" AND LOCALIZED RAINFALL  
TOTALS BETWEEN 3-5"+. WILL HOLD OFF ON A HEADLINE FOR NOW AND  
LET THE NEXT SHIFT REASSESS LATEST CAM TRENDS.  
 
THE 12Z/8.7 ECMWF EFI DATA WAS ALREADY SHOWING 0.6-0.7 VALUES  
FOR 24 HR QPF BETWEEN SATURDAY 7 PM TO SUNDAY 7 PM, ALONG WITH  
LOWER END SHIFT OF TAILS VALUES. WOULDN'T BE SURPRISED FOR THE  
NEW FORECAST DATA TO HAVE A STRONGER SIGNAL FOR HEAVY RAINFALL  
AMOUNTS. THE 00Z HREF PMM 24 HR QPF THROUGH 7 PM SATURDAY HAS A  
3-4" MAX ACROSS A LARGE PORTION OF SOUTHWEST TO SOUTH-CENTRAL  
WISCONSIN. THE BULK OF THIS ACTIVITY TO OUR NORTH IS ANTICIPATED  
TO DIVE SOUTHWARD THROUGH THE EVENING INTO SATURDAY NIGHT, WITH  
THE MAJORITY OF OUR HEAVIEST RAIN EXPECTED FOR THE LATE EVENING  
AND OVERNIGHT INTO SUNDAY AM.  
 
WPC HAS RAMPED UP QPF POTENTIAL THROUGH SUNDAY NIGHT, PAINTING  
A WIDESPREAD 2-4"+ ACROSS THE OUTLOOK AREA. IF THIS WIDESPREAD  
HEAVY RAINFALL PANS OUT, SIGNIFICANT RISES ON AREA TRIBUTARY  
RISES CAN BE EXPECTED. WPC HAS A SLIGHT RISK (LEVEL 2 OF 4) FOR  
FLASH FLOODING ACROSS THE ENTIRE AREA ON BOTH SATURDAY AND  
SUNDAY.  
 
RISK FOR SEVERE STORMS: ANOTHER CONCERN IN ADDITION TO FLASH  
FLOODING IS A RISK FOR STRONG TO SEVERE STORMS CAPABLE OF  
PRODUCING DAMAGING WINDS LATER SATURDAY AFTERNOON INTO SATURDAY  
NIGHT. SPC HAS EXPANDED THE SLIGHT RISK (LEVEL 2 OF 5) DOWN  
TOWARD THE HIGHWAY 30 CORRIDOR AND HAS AS A MARGINAL RISK  
(LEVEL 1 OF 5) TO THE SOUTH.  
 

 
   
LONG TERM /SUNDAY THROUGH THURSDAY/
 
 
ISSUED AT 330 AM CDT FRI AUG 8 2025  
 
BOUTS OF HEAVY RAINFALL MAY CONTINUE INTO SUNDAY, ALTHOUGH  
CONFIDENCE ON THE PLACEMENT OF THE SURFACE BOUNDARY IS LOW DUE  
TO ITS DEPENDENCE ON HOW THE SATURDAY NIGHT CONVECTION EVOLVES.  
HEADING INTO NEXT WEEK, WE'LL CONTINUE TO SEE SHORTWAVES PASSING  
THROUGH THE AREA NEAR- DAILY. THUS, WE ARE LOOKING AT THE  
POTENTIAL FOR DAILY CHANCES OF PRECIPITATION OVER MUCH OF THE  
AREA THROUGH AT LEAST TUESDAY. AT THIS TIME, IT DOESN'T SEEM TO  
BE A COMPLETE WASHOUT THROUGH THAT TIMEFRAME. RATHER, THERE  
SHOULD BE PLENTY OF DRY TIME BETWEEN PASSING SYSTEMS. WITH THIS  
PATTERN IN PLACE, WE WILL REMAIN WARM AND HUMID THROUGH THE  
FIRST HALF OF NEXT WEEK. TOO SOON TO DETERMINE ANY SEVERE THREAT  
WITH THESE PASSING WAVES.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
 
 
ISSUED AT 1245 AM CDT FRI AUG 8 2025  
 
VFR IS EXPECTED TO PREVAIL THROUGH THE PERIOD WITH INCREASING S TO  
SSE WINDS ON FRIDAY, GUSTING 20-25 KTS AT TIMES. THERE IS A SLIGHT  
CHANCE (<20%) FOR A FEW SHOWERS AND ISOLATED THUNDERSTORMS TO  
DEVELOP LATE TONIGHT INTO EARLY FRIDAY MORNING (06Z-12Z); CONFIDENCE  
REMAINS VERY LOW ON THE POTENTIAL AND COVERAGE SO DID NOT MENTION IN  
THE TAFS WITH THIS UPDATE.  
 

 
   
DVN WATCHES/WARNINGS/ADVISORIES
 
 
IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR  
IAZ040>042-051>054-063>068-076>078-087>089-098-099.  
IL...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR  
ILZ001-002-007-009-015>018-024>026-034-035.  
MO...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR  
MOZ009-010.  
 

 
 

 
 
SHORT TERM...UTTECH  
LONG TERM...GUNKEL/UTTECH  
AVIATION...UTTECH  
 
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