994  
FXUS63 KDVN 240254  
AFDDVN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE QUAD CITIES IA IL  
954 PM CDT SAT JUN 23 2018  
   
..EVENING HYDROLOGY UPDATE
 
 
   
SYNOPSIS
 
 
ISSUED AT 244 PM CDT SAT JUN 23 2018  
   
SYNOPSIS
 
 
A MILD AIR MASS REMAINS IN PLACE OVER THE THE REGION TODAY, WITH  
TEMPERATURES AT 2 PM RANGING FROM 70 TO 80, WITH THE COOLEST  
READINGS UNDER CLOUD COVER. DEWPOINTS REMAIN RATHER HIGH CONSIDERING  
THIS IS SUPPOSED TO BE THE DRY AIR MASS COMPARED TO THE PAST WEEK.  
THE WET GROUND AND MATURING CROPS ARE LIKELY A FACTOR IN HOUR  
DEWPOINTS REMAINING IN THE LOWER 60S VS DROPPING TO THE 50S TODAY.  
THIS IS HELPING RETAIN CLOUD COVER AT LOW LEVELS, WHILE AT UPPER  
LEVELS, A SHORT WAVE IS MOVING EAST THROUGH IOWA. THE WEAK LIFT IS  
BRINGING A FEW SPRINKLES AND EXTREMELY SMALL SHOWERS TO THE LOCAL  
AREA. SHOWERS SEEM TO BE LIMITED TO A DIAMETER OF NO MORE THAN 2  
MILES.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH SUNDAY)  
ISSUED AT 244 PM CDT SAT JUN 23 2018  
 
EARLY EVENING SPRINKLES WILL DISSIPATE BY 8 PM. INSTABILITY WILL BE  
MARGINAL AT BEST, SO MEASURABLE RAIN REMAINS A VERY LOW PROBABILITY.  
WITH PARTLY CLOUD TO CLOUDY SKIES THIS EVENING, TEMPERATURES WILL BE  
SLOW TO FALL, AND WITH INCREASING DEWPOINT, TONIGHT'S LOWS SHOULD  
ONLY FALL TO THE LOWER TO MID 60S IN MOST SPOTS. SUNDAY, PARTLY TO  
MOSTLY CLOUDY SKIES WILL AGAIN KEEP HEATING DOWN FROM THE WARMING  
ATMOSPHERE'S POTENTIAL. LOWER TO MID 80S SHOULD BE ALL WE CAN  
ACCOMPLISH FOR HIGHS AS MID CLOUDS ADVECT INTO THE WEST. WE STILL  
HAVE THE LOW POPS WEST FOR SHOWERS AND THUNDERSTORMS BUT OVER ALL  
THE MODELS HAVE SLOWED THE FORCING FOR THIS EVENT UNTIL MUCH LATER  
INTO MONDAY.  
   
LONG TERM
 
(SUNDAY NIGHT THROUGH SATURDAY)  
ISSUED AT 244 PM CDT SAT JUN 23 2018  
 
THREE MAIN THEMES IN THE EXTENDED FORECAST. THE FIRST IS A BEAUTIFUL  
WEEKEND BEFORE A TRANSITION TO SOUTHWEST FLOW AND A RETURN OF  
MOISTURE AND THUNDERSTORM CHANCES AND FINALLY THE HEAT TO END THE  
WEEK. TEMPERATURES ARE EXPECTED IN THE 80S SUNDAY WITH DEWPOINTS IN  
THE LOW TO MID 60S. THIS SHOULD MAKE FOR A GOOD DAY AS WELL.  
 
MONDAY INTO TUESDAY, CONSENSUS IS THAT THE 70 DEGREE DEWPOINTS  
RETURN TO THE AREA ALONG WITH H85 FLOW AND A H5 WAVE. THIS IS THE  
FIRST DECENT WAVE IN A LONG TIME THAT WILL HAVE SHEAR WITH IT. AT  
THIS TIME, IT APPEARS THAT AN ELEVATED BAND OF WAA CONVECTION WILL  
OVERSPREAD THE AREA SUNDAY NIGHT INTO MONDAY. HOW LONG THIS  
CONVECTION REMAINS AND HOW MUCH DESTABILIZATION CAN OCCUR WILL  
GREATLY AFFECT CONVECTION LATER IN THE DAY. THAT SAID, IF THIS CAN  
OCCUR LOW LEVEL SHEAR WILL BE CONDUCIVE FOR SEVERE WEATHER.  
OBVIOUSLY A LOT OF MESOSCALE DETAILS TO BE RESOLVED IN THE COMING  
DAYS BUT THE THREAT REMAINS.  
 
LATER INTO THE WEEK H5 RIDGE BUILDS INTO THE AREA. CURRENT IDEA IS  
THE CAP WILL REMAIN SOUTH OF THE AREA SO THAT NIGHTTIME MCSS LOOK  
POSSIBLE. WE LOOK TO BE HAVING A RAINY END TO THE LONG TERM. THIS  
COULD ADD TO CURRENT FLOODING AS WELL.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)  
ISSUED AT 646 PM CDT SAT JUN 23 2018  
 
SKIES WILL BECOME PARTLY CLOUDY TO MOSTLY CLEAR TONIGHT INTO SUNDAY  
WITH VFR CONDITIONS WITH LIGHT WINDS TONIGHT BECOMING LIGHT SOUTHEAST  
ON SUNDAY. ANY CLOUD BASES WILL BE ABOVE 4K AGL UNDER WEAK HIGH PRESSURE.  
 

 
   
HYDROLOGY
 
 
ISSUED AT 945 PM CDT SAT JUN 23 2018  
 
LITTLE CHANGE WITH THE EVENING RIVER FORECASTS. ON THE  
MISSISSIPPI, LD 16 AT IL CITY WILL GET CLOSE TO MODERATE FLOOD  
STAGE BY DAY 7 IN EARLY JULY AND MAY HAVE TO UPGRADE IN LATER  
FORECASTS. OTHERWISE NO CATEGORY CHANGES FOR NOW ON THE REST OF  
THE MISSISSIPPI. LD11 AT DUBUQUE, LD 13 FULTON, AND LD 14  
LECLAIRE ALL GET CLOSE TO OR EVEN SURPASS FLOOD STAGE BUT WITH  
LOWER CONFIDENCE, THUS RIVER FLOOD WATCHES CONTINUE FOR THOSE  
SITES UNTIL A BETTER HANDLE ON ROUTED FLOW IS ATTAINED. ON THE  
TRIBS, COMO ON THE ROCK RIVER DROPPED BELOW FLOOD STAGE EARLIER  
THIS SATURDAY AFTERNOON, WHILE BOTH JOSLIN AND MOLINE CONTINUE TO  
RISE AT SHARP RATES ABOVE MODERATE FLOOD STAGE AND SHOULD CREST  
SUNDAY AFTERNOON INTO EVENING. MODERATE FLOODING ALSO CONTINUES ON  
THE WAPSIPINICON RIVER NEAR DE WITT.  
 
WITH ROUNDS OF MORE RAIN, SOME POSSIBLY HEAVY, EXPECTED ON MONDAY  
INTO TUESDAY, THE FORECAST CRESTS AND/OR POST-CREST RECESSIONS  
MAY BE PROLONGED OR CHANGED, DEPENDING ON WHERE AND HOW MUCH RAIN  
FALLS NEXT WEEK.  
 

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

 
 

 
 
SYNOPSIS...ERVIN  
SHORT TERM...ERVIN  
LONG TERM...ERVIN  
AVIATION...16  
HYDROLOGY...12/COUSINS  
 
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