789  
FXUS63 KDVN 171053  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
553 AM CDT MON AUG 17 2026  
   
KEY MESSAGES  
 
- HIGH PRESSURE WILL REMAIN DRAPED OVER THE REGION THROUGH THE  
START OF THE WORK WEEK, BRINGING SEASONAL TEMPERATURES AND  
MOSTLY CLEAR SKIES.  
 
- A STORM SYSTEM WILL PASS THROUGH THE AREA TUESDAY INTO  
WEDNESDAY, BRINGING THE CHANCE FOR THUNDERSTORMS. A FEW STORMS  
MAY BE STRONG TO SEVERE.  
 
- ANOTHER STRETCH OF QUIETER WEATHER RETURNS LATE IN THE WEEK  
AND INTO THE WEEKEND, WITH LIMITED PRECIPITATION CHANCES.  
 
 
   
SHORT TERM /THROUGH TUESDAY NIGHT/  
 
ISSUED AT 127 AM CDT MON AUG 17 2026  
 
THE STRETCH OF HEAVY RAINFALL AND SEVERE STORMS HAS FINALLY COME TO  
A CLOSE, AS HIGH PRESSURE SLIDES OVER THE REGION TODAY. WE ARE  
GEARED TO HAVE QUITE THE BEAUTIFUL START TO THE WORK WEEK. ASIDE  
FROM DIURNAL CUMULUS, MOSTLY CLEAR SKIES WILL BE SEEN, WITH LIGHT  
NORTHWESTERLY WINDS AND TEMPERATURES AROUND 80. TONIGHT, HIGH  
PRESSURE WILL BE SOUTHEAST OF THE AREA, WITH LLVL WINDS SHIFTING  
SOUTHWESTERLY. AN INCREASE IN LLVL MOISTURE WILL RESULT, WITH  
INCREASING MID-HIGH CLOUDS THROUGH THE NIGHT. DRY CONDITIONS WILL  
REMAIN THROUGH MUCH IF NOT ALL OF THE NIGHT, WITH TEMPERATURES IN  
THE LOW-MID 60S. THE HRRR CONTINUES TO BRING IN A DECAYING LINE OF  
SHOWERS/STORMS, LARGELY IMPACTING OUR NORTHERN COUNTIES AND DRYING  
UP AS IT PROGRESSES THROUGH THE AREA. ALTHOUGH, MUCH OF THE SHORT  
TERM MODEL SUITE KEEPS US DRY THROUGH TONIGHT.  
 
A SHORTWAVE TROF WILL APPROACH THE AREA LATER ON TUESDAY, WITH WEAK  
BOUTS OF ENERGY PASSING OUT AHEAD OF IT. A 20-30 KT LLJ WILL ALSO BE  
IN PLACE OVERHEAD, INCREASING MOISTURE THROUGHOUT. THIS WILL CREATE  
AN ENVIRONMENT FAVORABLE FOR SHOWERS AND STORMS, WHICH CAN BE SEEN  
AS EARLY AS LATE MORNING. ALTHOUGH, FORCING ISN'T BEST UNTIL LATER  
IN THE DAY, ESPECIALLY AS A COLD FRONT CRASHES THROUGH THE AREA.  
THUS, ANY SHOWER/STORM ACTIVITY SHOULD REMAIN ISOLATED TO SCATTERED  
UNTIL THE AFTERNOON/EVENING HOURS. AS THE COLD FRONT APPROACHES  
TUESDAY EVENING/NIGHT, WE MAY HAVE AN ENVIRONMENT FAVORABLE FOR SOME  
ORGANIZED CONVECTION. DEEP-LAYER SHEAR WILL LARGELY REMAIN IN THE 30-  
40 KT RANGE WITH SUFFICIENT INSTABILITY, WHICH WOULD FAVOR MIXED-  
MODE CONVECTION THAT CAN GROW UPSCALE INTO A LINE OF STORMS. THE  
ENVIRONMENT IN PLACE WOULD FAVOR THE CHANCE FOR A FEW STRONG TO  
SEVERE STORMS, WITH WIND GUSTS BEING THE MAIN CONCERN. COMPARING TO  
PREVIOUS FORECAST RUNS, THE SEVERE THREAT DOES SEEM TO BE DECREASING  
A LITTLE. THIS COULD BE DUE TO THE AFOREMENTIONED DAYTIME  
SHOWERS/STORMS, WHICH MAY LIMIT AFTERNOON DESTABILIZATION AHEAD OF  
THE COLD FRONT, LEADING TO A MORE CONDITIONAL THREAT. THIS WILL BE  
SOMETHING TO CONTINUE MONITORING AS MORE SHORT TERM GUIDANCE COMES  
IN. SPC SEEMS TO HAVE PICKED UP ON THIS TREND, KEEPING MUCH OF THE  
AREA UNDER A MARGINAL RISK, LEVEL 1/5, AND TRIMMING THE SLIGHT RISK,  
LEVEL 2/5, TO OUR FAR WEST.  
 
 
   
LONG TERM /WEDNESDAY THROUGH SUNDAY/  
 
ISSUED AT 127 AM CDT MON AUG 17 2026  
 
WEDNESDAY MORNING, WE MAY CONTINUE TO SEE RESIDUAL SHOWERS/STORMS AS  
THE COLD FRONT FULLY EXITS THE AREA. AT THIS POINT, THE SEVERE  
THREAT WILL BE QUITE LIMITED. THUS, WE ARE NOT EXPECTING MANY  
IMPACTS AT THAT POINT. POST-FRONTAL AIRMASS WILL KICK IN WEDNESDAY,  
WITH LIGHT NORTHEASTERLY WINDS AND DECREASING CLOUD COVER. THE  
REMAINDER OF THE WORK WEEK SEEMS TO BE QUIET, WITH A SLIGHTLY COOLER  
AIRMASS IN PLACE AND MUCH LOWER HUMIDITY. WE WILL REMAIN UNDER WEAK  
NORTHWESTERLY FLOW ALOFT, WITH A FEW WEAK IMPULSES IN THE FLOW.  
ALTHOUGH, WITH LOW MOISTURE AND LACKING RETURN FLOW, WE ARE NOT  
EXPECTING MUCH RAIN FOR THE REST OF THE WEEK. AS WAS MENTIONED  
IN THE PREVIOUS DISCUSSION, ANY PRECIPITATION WILL LARGELY BE  
IN THE FORM OF ISOLATED INSTABILITY SHOWERS. A FEW GLOBAL MODELS  
INDICATE CHANCES LATE FRIDAY INTO SATURDAY MORNING, BUT  
CONFIDENCE IS LOW ON THIS. WILL STICK WITH WHAT THE NBM  
INITIALIZED, INTRODUCING 15-30% POPS FRIDAY EVENING/NIGHT.  
OTHERWISE, A MUCH NEEDED STRETCH OF MOSTLY-DRY WEATHER WILL BE  
SEEN, WITH COMFORTABLE HUMIDITY AND TEMPERATURES LARGELY IN THE  
UPPER 70S.  
 
 
   
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/  
 
ISSUED AT 550 AM CDT MON AUG 17 2026  
 
CAN'T RULE OUT A VERY BRIEF MVFR VISIBILITY REDUCTION IN MIST AT  
A FEW OF THE TERMINALS TO START OFF THE TAFS, BUT TOO LOW OF  
CONFIDENCE AND PROBABILITY TO MENTION. LAKE STRATUS SHOULD NOT  
IMPACT THE KMLI AND KBRL TERMINALS THIS MORNING WITH N/NE FLOW  
IN THE CLOUD BEARING LAYER STEERING THEM WELL TO THE EAST.  
OTHERWISE, VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE  
PERIOD WITH DIURNAL CUMULUS 2500-3500 FT BASES LIFTING AND  
DECREASING WITH INCREASED MIXING, WHICH WILL BUMP NW WIND TO  
AROUND 10+ KT BEFORE TURNING LIGHT WHILE BACKING FROM THE SSW  
AFTER SUNSET. THERE IS A LOW CHANCE FOR A SHOWER OR STORM TO  
APPROACH KCID AND KDBQ TERMINALS TOWARD THE END OF THE PERIOD,  
BUT THE PROBABILITY (20%) IS TOO LOW FOR ANY MENTION.  
 
 
   
DVN WATCHES/WARNINGS/ADVISORIES  
 
IA...NONE.  
IL...NONE.  
MO...NONE.  
 
 
 
 
 
SHORT TERM...GUNKEL  
LONG TERM...GUNKEL  
AVIATION...MCCLURE  
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