096  
FXUS63 KDVN 141139  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
639 AM CDT FRI AUG 14 2020  
   
..AVIATION UPDATE
 
 
   
SYNOPSIS
 
 
ISSUED AT 300 AM CDT FRI AUG 14 2020  
 
HIGH PRESSURE WAS IN CONTROL OVER THE GREAT LAKES INTO PORTIONS OF  
THE MID TO UPPER MISSISSIPPI VALLEY. AS OF 3 AM, TEMPERATURES  
ACROSS EASTERN IOWA AND NORTHWEST ILLINOIS WERE IN THE 60S TO  
LOWER 70S. THE COOL SPOT WAS FREEPORT AT 60 F AND THE WARMEST  
LOCATION WAS BURLINGTON AT 73 F.  
 

 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 300 AM CDT FRI AUG 14 2020  
 
ANOTHER VERY WARM DAY IS ON TAP WITH HIGHS IN THE MID TO UPPER  
80S EXPECTED FOR MOST OF THE FORECAST AREA. LIGHT ESE TO SE WINDS  
SHOULD ADVECT IN SLIGHTLY LESS HUMID AIR COMPARED TO YESTERDAY,  
WITH DEWPOINTS IN THE LOW TO MID 60S EAST AND UPPER 60S WEST.  
 
CONVECTION IS EXPECTED TO DEVELOP THIS AFTERNOON ALONG A COLD  
FRONT DRAPED ACROSS SOUTHWEST MINNESOTA AND NORTHWEST IOWA. THIS  
ACTIVITY WILL TRACK TO THE SE INTO TONIGHT, FOLLOWING THE  
850-300MB STEERING FLOW ALOFT. INSTABILITY AND FORCING WILL  
CONTINUE TO WANE OVERNIGHT WITH HREF MUCAPE DROPPING INTO THE  
1000-1500 J/KG RANGE ALONG AND WEST OF THE MISSISSIPPI RIVER.  
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LOCALLY, MAINLY  
AFTER MIDNIGHT WITH THE BEST CHANCES (30-50%) ACROSS THE WEST AND  
NORTHWEST FORECAST AREA. CHANCES THEN TAPER OFF TO 20% AROUND THE  
QUAD CITIES FOR VERY LATE TONIGHT INTO EARLY SATURDAY MORNING.  
 
COVERAGE OF THE RAIN WILL LIKELY REMAIN SCATTERED AT BEST. THEREFORE,  
IT DOES NOT APPEAR THIS WILL BE THE WIDESPREAD SOAKING RAIN THAT  
IS NEEDED ACROSS MUCH OF THE REGION, WHICH HAS BEEN ABNORMALLY  
DRY THE PAST SEVERAL WEEKS. UTTECH  
   
LONG TERM
 
(SATURDAY THROUGH THURSDAY)  
ISSUED AT 300 AM CDT FRI AUG 14 2020  
 
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD. THE MAIN  
FORECAST CONCERNS WERE CHANCES OF PRECIPITATION THROUGH THE PERIOD.  
 
A COLD FRONT WILL BE APPROACHING THE MISSISSIPPI RIVER BY 12 UTC ON  
SATURDAY WHEN THE LONG TERM FORECAST PERIOD BEGINS. AT 500 MB, A  
SHORTWAVE TROUGH AND A 250 MB JET STREAK ARE FORECAST TO DIG INTO  
MINNESOTA AND WISCONSIN DURING THE DAY ON SATURDAY AND QUICKLY DRIVE  
THE PREVIOUSLY MENTIONED COLD FRONT ACROSS NORTHWEST ILLINOIS. THE  
BETTER FORCING IS TO OUR NORTH AND CONVERGENCE ALONG THE FRONT IS  
FORECAST TO BE WEAK WITH A BRIEF WINDOW OF SCATTERED SHOWERS AND  
THUNDERSTORMS ALONG THE FRONT. INSTABILITY WILL BE LIMITED GIVEN THE  
TIME OF DAY AND THE SHEAR WILL BE WEAK ACROSS THE AREA SO THE THREAT  
FOR SEVERE STORMS APPEARS TO BE LOW.  
 
IN THE WAKE OF SATURDAYS STORMS SYSTEM AND COLD FRONT, COOLER AND  
LESS HUMID AIR WILL MOVE INTO THE REGION AND REMAIN THERE THROUGH  
THE REMAINDER OF THE PERIOD. THE TROUGH DIGGING INTO THE EASTERN US  
AND A RIDGING BUILDING ACROSS THE WESTERN US WILL RESULT IN  
NORTHWESTERLY FLOW ALOFT ACROSS EASTERN IOWA, NORTHWEST ILLINOIS AND  
FAR NORTHEAST MISSOURI. THE JET STREAM WILL BE WELL NORTH OF THE  
AREA THROUGH THE PERIOD. HOWEVER MODELS DO DEPICT SEVERAL SHORTWAVES  
MOVING THROUGH THE NORTHWESTERLY FLOW THROUGH THE PERIOD. MOISTURE  
WILL BE LIMITED AND THESE PASSING SHORTWAVES WILL LIKELY RESULT IN  
CLOUD COVER AND NOT RAIN. AFTER NEAR NORMAL TEMPERATUES ON SATURDAY  
SUNDAY, EXPECT NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES THROUGH  
THE REMAINDER OF THE WEEK. NORMAL HIGH TEMPERATURES FOR THE MIDDLE  
THIRD OF AUGUST RANGE FROM 80 TO 85 DEGREES FROM NORTH TO SOUTH  
ACROSS THE AREA WITH NORMAL LOW TEMPERATURES AROUND 60 TO 64  
DEGREES. DEWPOINTS WILL BE IN A COMFORTABLE MID TO UPPER 50S.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)  
ISSUED AT 630 AM CDT FRI AUG 14 2020  
 
HIGH PRESSURE IS MOVING ACROSS THE AREA THIS MORNING WITH VFR  
CEILINGS AND VISIBILITIES ACROSS THE AREA. SOME AVIATION FOG THIS  
MORNING WITH VISIBILITIES BETWEEN 3 AND 5 MILES. CONDITIONS WILL  
IMPROVE THROUGH 15 UTC.  
 
A COLD FRONT IS FORECAST TO MOVE THROUGH EASTERN IOWA TAF SITES  
TONIGHT WITH WINDS REMAINING LIGHT BUT SWITCHING TO THE NORTHWEST  
BEHIND THE FRONT. CEILINGS WILL REMAIN VFR THROUGH THE PERIOD.  
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ALONG THE FRONT  
BUT CONFIDENCE IS LOW THAT THEY WILL IMPACT ANY ONE LOCATION.  
 

 
   
DVN WATCHES/WARNINGS/ADVISORIES
 
 
IA...NONE.  
IL...NONE.  
MO...NONE.  

 
 

 
 
SYNOPSIS...UTTECH  
SHORT TERM...UTTECH  
LONG TERM...COUSINS  
AVIATION...COUSINS  
 
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