351  
FXUS63 KDVN 181849  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
149 PM CDT TUE AUG 18 2026  
   
KEY MESSAGES  
 
- A STORM SYSTEM WILL DRAG A COOL FRONT THROUGH THE AREA TONIGHT  
INTO WEDNESDAY, BRINGING SOME SHOWERS AND THUNDERSTORMS. A  
COUPLE OF STORMS MAY BE STRONG TO SEVERE BUT CONFIDENCE IS  
LOW.  
 
- OUTSIDE OF ANOTHER FRONT BRING A SHOWER AND THUNDERSTORM RISK  
TO THE AREA LATE THURSDAY NIGHT INTO FRIDAY EVENING,  
PRECIPITATION CHANCES LOOK TO BE VERY LIMITED OVER THE NEXT 7  
DAYS.  
 
 
   
SHORT TERM /THROUGH WEDNESDAY/  
 
ISSUED AT 147 PM CDT TUE AUG 18 2026  
 
SATELLITE TRENDS SHOW CLEARING OCCURRING AHEAD OF THE APPROACHING  
COOL FRONT. THE OVERALL FORCING IS WEAK AS IS THE CONVERGENCE ALONG  
THE FRONT. THUS THERE ARE QUESTIONS REGARDING THE POTENTIAL FOR RAIN.  
 
BASED ON RADAR/SATELLITE TRENDS THROUGH EARLY AFTERNOON, PRUDENCE  
DICTATES GOING WITH A 15-50 PERCENT CHANCE OF RAIN LATE THIS  
AFTERNOON WITH THE BETTER CHANCES NORTH OF HIGHWAY 30.  
 
THE CLOUD COVER AND RELATIVELY COOLER TEMPERATURES WILL RESULT IN  
LIMITED INSTABILITY FOR STORMS. HOWEVER, PROGGED SOUNDINGS OF THE  
ATMOSPHERE DO GIVE WEAK SUPPORT THAT A COUPLE OF STORMS COULD BE  
STRONG TO SEVERE. IF THIS SCENARIO DOES OCCUR, THE PRIMARY RISK  
WOULD BE HAIL FOR AREAS ALONG/NORTH OF HIGHWAY 30.  
 
ONCE SUNSET OCCURS THE OVERALL COVERAGE OF CONVECTION WILL DROP WITH  
SOME WEAK BUT ISOLATED CONVECTION FESTERING THE REMAINDER OF THE  
NIGHT.  
 
ON WEDNESDAY THERE SHOULD BE SOME LINGERING CONVECTION SOUTH OF I-80  
DURING THE MORNING THAT SLOWLY DISSIPATES. IF DIURNAL CONVECTION  
DEVELOPS WEDNESDAY AFTERNOON, IT WOULD BE ISOLATED DUE TO THE LACK  
OF UPPER AIR SUPPORT AND WOULD BE CONFINED TO AREAS SOUTH OF  
I-80.  
 
 
   
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/  
 
ISSUED AT 147 PM CDT TUE AUG 18 2026  
 
WEDNESDAY NIGHT THROUGH TUESDAY...  
ASSESSMENT...LOW (20-30%) CONFIDENCE ON LATE WEEK RAIN CHANCES  
 
THE MODELS HAVE ANOTHER FRONT MOVING THROUGH THE AREA IN THE LATE  
THURSDAY NIGHT THROUGH FRIDAY EVENING TIME FRAME. NORTHWEST FLOW  
ALOFT DOMINATES WELL INTO NEXT WEEK SO THE OVERALL MOISTURE  
AVAILABLE FOR RAIN WILL BE LIMITED. THE CURRENT MODEL CONSENSUS IS  
AT A 20-35% CHANCE OF RAIN WITH THE BETTER CHANCES GENERALLY ALONG  
AND NORTH OF I-80.  
 
OUTSIDE OF THIS TIME PERIOD, THE PROSPECTS FOR RAIN IS VERY LIMITED  
WITH TEMPERATURES NEAR NORMAL.  
 
 
   
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/  
 
ISSUED AT 1221 PM CDT TUE AUG 18 2026  
 
WEAK FORCING AHEAD AND ALONG AN APPROACHING COLD FRONT SHOULD  
GENERATE ISOLATED (20-30%) COVERAGE OF SHRA/TSRA THROUGH 06Z/19  
ACROSS EASTERN IOWA AND NORTHERN ILLINOIS. AFTER 06Z/19 LIGHT  
WINDS SHOULD RESULT IN POCKETS OF MVFR/IFR CONDITIONS IN LIGHT  
FOG. FOG THAT FORMS SHOULD BURN OFF BY 15Z/19.  
 
 
   
DVN WATCHES/WARNINGS/ADVISORIES  
 
IA...NONE.  
IL...NONE.  
MO...NONE.  
 
 
 
 
 
SHORT TERM...08  
LONG TERM...08  
AVIATION...08  
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