913  
FXUS63 KDVN 131957  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
257 PM CDT THU AUG 13 2020  
   
SYNOPSIS
 
 
ISSUED AT 256 PM CDT THU AUG 13 2020  
 
AS OF 2 PM, A RIDGE OF HIGH PRESSURE REMAINED OVER THE AREA, BUT WAS  
MOVING OFF TO THE NORTHEAST. SOME DIURNAL CUMULUS CLOUD FIELD HAD  
DEVELOPED WITH SCATTERED TO OCCASIONALLY BROKEN CLOUD DECK AT 2K TO  
4K FEET. A WARM FRONT WAS NEARLY STILL FROM NORTH CENTRAL IOWA TO  
SOUTHEAST IOWA. DEW POINTS WERE IN THE UPPER 60S AND LOWER 70S WITH  
AT FEW MID 60S IN NORTHERN ILLINOIS SITES. TEMPERATURES WERE IN THE  
LOWER 80S NORTH TO UPPER 80S SOUTH.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH FRIDAY)  
ISSUED AT 256 PM CDT THU AUG 13 2020  
 
TONIGHT, A RIDGE OF HIGH PRESSURE WILL REMAIN STRETCHED FROM THE  
GREAT LAKES THROUGH EASTERN IOWA, BUT WILL SLOWLY CONTINUE TO MOVE  
OFF TO THE NORTHEAST. A LIGHT EASTERLY BREEZE WILL PREVAIL WITH  
MOSTLY CLEAR SKIES. TEMPERATURES LOOK TO BE ON TRACK WITH LOWS IN  
THE LOWER 60S NE TO UPPER 60S SOUTH. THERE MAY BE SOME PATCHY FOG IN  
THE PREDAWN HOURS, BUT LEFT MENTION OUT OF FORECAST AT THIS TIME.  
 
FRIDAY, DRY CONDITIONS WILL CONTINUE AS THE RIDGE MOVES FURTHER EAST  
AND THE WARM FRONT REMAINS STATIONARY. WITH PLENTY OF SUNSHINE,  
TEMPERATURES WILL CLIMB INTO THE MID TO UPPER 80S. WITH THE HIGH  
HUMIDITY LEVELS, HEAT INDICES WILL PUSH INTO THE UPPER 80S TO LOW  
90S.  
   
LONG TERM
 
(FRIDAY NIGHT THROUGH THURSDAY)  
ISSUED AT 256 PM CDT THU AUG 13 2020  
 
RELATIVELY BENIGN EXTENDED PERIOD ASIDE FROM A FRONTAL PASSAGE ON  
SATURDAY, WHICH WILL BRING SHOWERS AND STORMS TO THE AREA. A DRY  
CANADIAN HIGH PRESSURE WILL DOMINATE THE REMAINDER OF THE LONG TERM  
PERIOD, BRINGING DRY, FALL-LIKE TEMPERATURES WITH LOW HUMIDITY.  
 
SATURDAY, A COLD FRONT WILL MOVE THROUGH THE AREA BY MID AFTERNOON.  
IT IS EXPECTED TO ENTER THE NW PART OF THE CWA LATE FRIDAY NIGHT,  
MOST LIKELY AFTER MIDNIGHT. IT THEN WILL QUICKLY PASS THROUGH THE  
CWA EXITING THE EASTERN PORTIONS DURING THE MID TO LATE AFTERNOON.  
THE CURRENT BLEND HAS 30 TO 40 PERCENT POPS FOR THE FROPA RAINS WITH  
RELATIVELY LOW RAINFALL AMOUNTS EXPECTED. HIGHS WILL BE IN THE LOW  
TO MID 80S. THE SPC HAS A MARGINAL RISK OF SEVERE STORMS ALONG AND  
EAST OF THE MS RIVER FOR SATURDAY, WITH WIND AND HAIL THE MAIN  
CONCERNS. SINCE IT IS COMING THROUGH EARLIER IN THE DAY, THE RISK  
AREA MAY MOVE FURTHER TO THE EAST WITH BETTER HEATING AND THUS  
INSTABILITY.  
 
DRY CONDITIONS WITH PLENTY OF SUNSHINE AND MUCH LOWER HUMIDITY  
LEVELS WILL ROUND OUT THE REMAINDER OF THE LONG TERM PERIOD. HIGHS  
WILL BE IN THE UPPER 70S AND LOWS 80S, WITH SOME MID 70S NE ON  
TUESDAY.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)  
ISSUED AT 1222 PM CDT THU AUG 13 2020  
 
VFR WILL PREVAIL THROUGH THE FORECAST PERIOD. THERE MAY BE SOME  
BROKEN MVFR CIGS THIS AFTERNOON WITH A CUMULUS FIELD BUT OPTED TO  
KEEP SCATTERED FOR NOW. LATE TONIGHT, SOME MODELS SHOW  
VISIBILITIES OF 2 TO 5 SM IN THE 09-12Z TIME FRAME, BUT KEPT  
MENTION OUT OF FORECAST. OTHERWISE, LIGHT EAST SOUTHEAST WINDS AND  
SCATTERED HIGH CLOUDS WILL BE COMMON.  
 

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

 
 

 
 
SYNOPSIS...14  
SHORT TERM...14  
LONG TERM...14  
AVIATION...14  
 
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