804  
FXUS63 KDVN 291735  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
1235 PM CDT WED JUN 29 2016  
   
..AVIATION UPDATE
 
 
   
SYNOPSIS
 
 
ISSUED AT 300 AM CDT WED JUN 29 2016  
 
AS OF 300 AM...VERY COOL BY MID JUNE STANDARDS. TEMPS CURRENTLY  
IN THE LOWER TO UPPER 50S UNDER CLEAR SKIES.  
 

 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 300 AM CDT WED JUN 29 2016  
 
TODAY...ANOTHER COMFORTABLE DAY WITH HIGH TEMPS IN THE UPPER 70S  
TO LOWER 80S AND DEWPOINTS IN THE 50S. THERE IS A SLIGHT CHANCE  
FOR AN ISOLATED SHOWER OR THUNDERSTORM OVER THE EXTREME WESTERN  
SECTION OF THE FORECAST AREA THIS AFTN. HOWEVER, FACTORS SUCH AS  
A DRY SFC-500MB TROPOSPHERIC PROFILE, LOW PWATS UNDER 1 INCH, AND  
VERY WEAK QG FORCING ALL FAVOR DRY CONDITIONS FOR MOST AREAS.  
 
BY THE EVENING, INCREASING MOISTURE (PWATS UP TO 1.25 INCHES) AND  
MUCAPE AT OR SLIGHTLY ABOVE ~500 J/KG ACROSS THE WESTERN CWA WILL  
BE AN ENVIRONMENT CONDUCIVE FOR AN ISOLATED SHOWER OR STORM. AT  
THIS TIME, POPS ARE BETWEEN 20-40%. HI-RES MODELS SUCH AS THE  
HRRR/NAM/ARW KEEP COVERAGE VERY ISOLATED.  
 
TONIGHT...MODELS ARE TRACKING A VORTICITY MAX THROUGH THE UPPER  
MISSISSIPPI RIVER VALLEY FROM THE NW. GFS MORE AGGRESSIVE IN  
EXTENDING ISOLATED SHOWERS AND THUNDERSTORMS INTO THE DVN CWA,  
ESPECIALLY WEST OF THE MISSISSIPPI RIVER. ECMWF/NAM12, ARE CLOSE  
TO DRY. MARGINAL 850MB MOISTURE CONVERGENCE AND WV TRANSPORT GIVES  
ME LOW CONFIDENCE ON PRECIP COVERAGE ABOVE ISOLATED. HIGHEST POPS  
OF ~40% ARE OVER THE SW CWA.  
 
THINKING MANY AREAS LIKELY TO REMAIN DRY INTO THURSDAY MORNING AS  
IT WILL BE DIFFICULT TO SIGNIFICANTLY AND RAPIDLY SATURATE THE  
COLUMN ON THE HEELS OF A LARGE AREA OF HIGH PRESSURE. UTTECH  
   
LONG TERM
 
(THURSDAY THROUGH TUESDAY)  
ISSUED AT 300 AM CDT WED JUN 29 2016  
 
A COLD FRONT WILL PUSH THROUGH THE FORECAST AREA THURSDAY AND  
THURSDAY EVENING. THE NAM HAS BEEN PERSISTENT IN SPREADING A SWATH  
OF HEAVY RAIN ACROSS THE SOUTH, BUT IS LIKELY TOO MOIST. THE ECMWF  
BARELY CLIPS THE NORTHEAST AND MAY BE TOO DRY. THE GFS AND GEM ARE  
THE MORE MODERATE SOLUTIONS. RIGHT NOW, IT SEEMS REASONABLE TO GO  
WITH A BAND OF HIGH CHANCE POPS FROM NORTHWEST TO SOUTHEAST, WHICH  
CAN BE ADJUSTED EITHER WAY AS THE EVENT NEARS. THE FAR SOUTH IS  
OUTLOOKED IN THE DAY 2 MARGINAL RISK AREA. FORECAST SOUNDINGS  
INDICATE A TALL, SKINNY CAPE PROFILE WITH STEEP LOW LEVEL LAPSE  
RATES, AND PRECIPITABLE WATER VALUES BETWEEN 1.5 AND 2 INCHES.  
MODEST MID-LEVEL LAPSE RATES AND DEEP LAYER SHEAR SHOULD PRECLUDE A  
LARGE HAIL THREAT. THE MAIN ISSUES WILL LIKELY BE ISOLATED STRONG  
WIND GUSTS AND LOCALIZED HEAVY RAIN.  
 
THE NEXT MAIN WINDOW OF POTENTIAL SHOWERS AND STORMS IN THE LONG  
TERM PERIOD WILL BE LATE SATURDAY THROUGH SUNDAY. THE GFS AND ECMWF  
ADVERTISE A DECENT SHORTWAVE TROUGH AND A WARM FRONT POISED TO THE  
SOUTH. MODEL CONSENSUS FAVORS THE SOUTHERN THIRD OF THE FORECAST  
AREA FOR ADDITIONAL RAIN.  
 
TEMPERATURES THROUGH THE LONG TERM PERIOD WILL BE BELOW NORMAL  
THROUGH SUNDAY, WITH HIGHS IN THE UPPER 70S TO LOW 80S, BEFORE A  
BROAD UPPER RIDGE BEGINS TO INFLUENCE THE AREA EARLY NEXT WEEK.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)  
ISSUED AT 1230 PM CDT WED JUN 29 2016  
 
VFR CONDITIONS ARE EXPECTED THROUGH 12Z/30. A WEAK UPPER LEVEL  
DISTURBANCE WAS PRODUCING CONVECTION ACROSS CENTRAL IOWA. HOWEVER,  
THE CONVECTION IS SLOWLY DISSIPATING AS IT ENCOUNTERS DRY AIR  
ACROSS EASTERN IOWA. VCSH ARE POSSIBLE AT KCID/KBRL. AFTER 12Z/30  
VFR CONDITIONS WILL CONTINUE. A COLD FRONT IS FORECAST TO MOVE  
THROUGH IOWA/ILLINOIS LATE THURSDAY AFTERNOON/NIGHT. MVFR/IFR  
CONDITIONS WILL BE POSSIBLE WITH CONVECTION ALONG/BEHIND THE  
FRONT.  
 

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

 
 

 
 
SYNOPSIS...UTTECH  
SHORT TERM...UTTECH  
LONG TERM...RP KINNEY  
AVIATION...08  
 
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