410  
FXUS63 KDVN 010001  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
701 PM CDT WED SEP 30 2020  
   
..AVIATION UPDATE
 
 
   
SYNOPSIS
 
 
ISSUED AT 253 PM CDT WED SEP 30 2020  
 
COOL AIR IS POURING INTO THE MIDWEST, THOUGH THE DEEP MIXING BEHIND  
THE COLD FRONT IS BOTH ALLOWING FOR A MILD HIGH TEMPERATURE TODAY  
AND HAS BROUGHT THE EXPECTED 2 TO 4 HOUR WINDOW OF STRONG WINDS THAT  
HAVE REACHED NEAR 45 MPH IN SPOTS, MEASURED ALMOST EXCLUSIVELY ON  
ASOS, WHICH IS A 10M MOUNTED WIND SPEED MEASUREMENT AND COULD BE  
HIGHER THAN THE AWOS UNITS.  
 
IN ANY CASE, IT'S WINDY, AND UPSTREAM, THERE AREA PLENTY OF  
INSTABILITY CLOUDS AND SCATTERED SHOWERS IN MN/WI.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH THURSDAY)  
ISSUED AT 253 PM CDT WED SEP 30 2020  
 
TONIGHT, AS TEMPERATURES COOL, THE CLOUDS AND SHOWERS TO THE  
NORTH SHOULD DECREASE AND WE SHOULD COOL INTO THE 40S, UNDER DRY  
OVERNIGHT CONDITIONS.  
 
THURSDAY, SIMILAR CONDITIONS TO WHAT IS SEEN IN MN/WI ARE EXPECTED  
HERE, WITH SCATTERED DIURNAL SHOWERS FORMING BY MID MORNING, AND  
LASTING THROUGH THE AFTERNOON. QPF SHOULD BE EXTREMELY LIGHT AND  
SPOTTY, BUT THE COVERAGE OF SHOWERS SHOULD BE ENOUGH TO WARRANT  
MODERATE CHANCE POPS. I'VE RETAINED A SLIGHT CHANCE FOR THUNDER AS  
WELL, AS EVEN LOW 50S WILL POSSIBLY PROVIDE CAPE VALUES OF 20 TO 50.  
 
WINDS ALOFT ARE WEAKER TOMORROW, THUS WINDS SHOULD NOT BE AS STRONG  
AS TODAY. IN ADDITION, EXTENSIVE CLOUD COVER MAY DEVELOP AS UPDRAFTS  
STRATIFY OUT INTO AN ELEVATED STRATOCUMULUS LAYER THROUGH THE  
MIDDLE OF THE DAY.  
 
ERVIN  
   
LONG TERM
 
(THURSDAY NIGHT THROUGH WEDNESDAY)  
ISSUED AT 253 PM CDT WED SEP 30 2020  
 
KEY POINTS...  
 
1. COLD START FRIDAY MORNING WITH PATCHY/AREAS OF FROST IN SOME  
PLACES  
 
2. 50S FRIDAY THROUGH SUNDAY, THEN A WARM-UP BACK INTO THE UPPER 60S  
TO MID 70S BY MID WEEK  
 
3. RAIN CHANCES SATURDAY INTO SUNDAY, THEN DRY  
 
THURSDAY NIGHT AND EARLY FRIDAY, HIGH PRESSURE WILL BE SETTLING OVER  
WESTERN AND CENTRAL IOWA, WHICH WILL PROVIDE THE AREA WITH LIGHT  
WINDS AND CLEARING SKIES. MODELS CONTINUE TO AGREE WITH -2 TO -4C  
850 MB TEMPS DROPPING OVER THE AREA. LOWS IN THE MID 30S WILL BE  
SEEN ALONG AND NORTH OF HIGHWAY 30 WITH UPPER 30S TO THE SOUTH.  
PATCHY TO AREAS OF FROST WILL LIKELY DEVELOP OVERNIGHT INTO FRIDAY  
MORNING WITH THE NW QUARTER OF THE CWA MOST LIKELY TO SEE FROST. IF  
WINDS STAY UP OVERNIGHT, FROST FORMATION MAY BE HINDERED.  
 
FRIDAY, THE HIGH PRESSURE RIDGE WILL KEEP WINDS ON THE LIGHT SIDE,  
BUT TEMPERATURES WILL BE CHILLY WITH HIGHS ONLY IN THE LOW TO MID  
50S. FRIDAY NIGHT INTO SATURDAY, THERE IS THE POSSIBILITY OF FROST  
IN PARTS OF NW IL, AS TEMPERATURES SLIP INTO THE MID 30S, BUT WITH  
CLOUD COVER INCREASING AHEAD OF THE NEXT RAIN-MAKER, OPTED TO LEAVE  
ANY MENTION OUT OF THE FORECAST AT THIS TIME.  
 
NOT MUCH CHANGE WAS MADE TO THE PERIOD BEYOND FRIDAY. THE CURRENT  
BLENDED FORECAST CONTINUES TO SHOW THE BEST CHANCES FOR RAIN (30-40  
PERCENT) SATURDAY AFTERNOON AND NIGHT. THIS IS A RESULT OF A LOW  
PRESSURE SYSTEM TRACKING JUST SOUTH OF THE CWA. LINGERING SLIGHT  
CHANCES REMAIN ALONG AND EAST OF THE MS RIVER ON SUNDAY.  
 
HIGH PRESSURE BUILDS BACK OVER THE AREA INTO NEXT WEEK WITH DRY  
CONDITIONS AND A GRADUAL WARMING TREND BACK INTO THE UPPER 60S TO  
MID 70S BY THE MIDDLE OF NEXT WEEK.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)  
ISSUED AT 653 PM CDT WED SEP 30 2020  
 
GUSTY WNW WINDS WILL SUBSIDE EARLY TONIGHT INTO THE 5-10 KT  
RANGE AS VFR PREVAILS. ANOTHER AREA OF LOW PRESSURE WILL BRING  
INCREASING WINDS AGAIN FOR THURSDAY ALONG WITH ISOLATED SHOWERS  
DURING THE AFTERNOON. THE STRONGEST SHOWERS COULD PRODUCE WIND  
GUSTS AROUND 30 KTS, BRIEF MVFR, AND POSSIBLY A RUMBLE OF THUNDER.  
 
A PUSH OF COLD AIR FROM THE NORTH, COMBINED WITH DAYTIME HEATING,  
COULD LEAD TO MVFR STRATOCUMULUS DEVELOPING BY MID TO LATE  
MORNING. THE BEST CHANCES FOR MVFR ARE AT KDBQ; KCID IS ON THE  
EDGE.  
 

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

 
 

 
 
SYNOPSIS...ERVIN  
SHORT TERM...ERVIN  
LONG TERM...14  
AVIATION...UTTECH  
 
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