261  
FXUS63 KILX 292320  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
620 PM CDT WED JUN 29 2016  
   
SHORT TERM
 
(TONIGHT)  
ISSUED AT 308 PM CDT WED JUN 29 2016  
 
REMNANTS OF EARLY MORNING CONVECTION ACROSS WESTERN IOWA CONTINUE TO  
DISSIPATE AS THEY TRACK TOWARD THE MISSISSIPPI RIVER THIS AFTERNOON,  
WITH 19Z/2PM RADAR IMAGERY ONLY SHOWING A FEW VERY LIGHT RETURNS  
LINGERING ACROSS EASTERN IOWA. AIRMASS FURTHER EAST INTO ILLINOIS  
IS QUITE DRY AS EVIDENCED BY AREA LAPS SOUNDINGS, SO THIS REMAINING  
VERY LIGHT PRECIP WILL COMPLETELY VANISH BEFORE IT REACHES THE  
WESTERN KILX CWA. HOWEVER, MID/HIGH CLOUDS ASSOCIATED WITH THE  
DYING SHOWERS WILL SPREAD INTO CENTRAL ILLINOIS LATE THIS AFTERNOON  
AND EVENING. ANOTHER CLUSTER OF NOCTURNAL THUNDERSTORMS IS EXPECTED  
TO DEVELOP LATER TONIGHT ACROSS PORTIONS OF IOWA AND/OR NORTHERN  
MISSOURI IN ASSOCIATION WITH A 20-30KT 850MB JET STREAK. WITH THIS  
ACTIVITY DEVELOPING SLIGHTLY FURTHER EAST THAN THE PREVIOUS NIGHT'S  
CONVECTION, IT STANDS A BETTER CHANCE OF SPILLING INTO WEST-CENTRAL  
ILLINOIS TOWARD DAWN THURSDAY BEFORE EVENTUALLY DISSIPATING FURTHER  
EAST INTO THE UNFAVORABLY DRY AIRMASS. AS SUCH, HAVE INCLUDED LOW  
CHANCE POPS ALONG/WEST OF A PEORIA TO SPRINGFIELD LINE MAINLY AFTER  
08Z/3AM. OVERNIGHT LOW TEMPERATURES WILL RANGE FROM THE MIDDLE 50S  
FAR NORTHEAST AROUND DANVILLE...TO AROUND 60 DEGREES IN THE ILLINOIS  
RIVER VALLEY.  
   
LONG TERM
 
(THURSDAY THROUGH WEDNESDAY)  
ISSUED AT 308 PM CDT WED JUN 29 2016  
 
FORECAST PROBLEM REMAINS THE NEXT 2 SYSTEMS TO AFFECT AREA AND THE  
RESULTANT PRECIPITATION FROM EACH.  
 
THE FIRST SYSTEM IS ANOTHER COLD FRONT FROM CANADA IN THE  
NORTHWEST FLOW OVER THE EASTERN HALF OF COUNTRY. THIS SYSTEM TO  
REACH EASTERN IA BY LATE IN THE AFTERNOON THURSDAY. RETURN FLOW OF  
SOUTHERLY WINDS AND MOISTURE WILL BRING A CHANCE INTO WEST AND  
NORTHWEST CWA AREAS FIRST, AHEAD OF THE FRONT, THOUGH POPS WILL BE  
IN CHANCE CATEGORY. BEST LIFT IS ALONG AND BEHIND THE FRONT AS IT  
REACHES IL ON THURS NIGHT, WITH BEST LIFT OVER THE NORTHERN  
SECTIONS OF STATE. AMOUNTS WILL BE LIGHT WITH THE SPEED OF FRONT  
AND AVAILABLE MOISTURE.  
 
THE MORE SIGNIFICANT CHANCE OF RAIN IS EXPECTED LATER, AS THE FRONT  
MOVES SOUTH AND STALLS OVER THE OH RIVER AND ACROSS SOUTHERN MO. THE  
MODELS ARE THEN CONSISTENT IN THE MOVEMENT OF A SHORT WAVE  
IMPULSE FROM THE CENTRAL ROCKIES INTO THE CENTRAL PLAINS, WITH AN  
OVERRUNNING PATTERN DEVELOPING NORTH OF THE STALLED FRONT. WITH  
THE FRONT OVER SOUTHERN MO AND SOUTHERN IL ON SAT MORNING, LIFT  
OVER THE FRONT SHOULD BRING AMPLE MOISTURE INTO THE AREA WITH  
SCATTERED THUNDERSTORMS. THE BEST CHANCES OF SIGNIFICANT RAINFALL  
OVER THE SOUTHERN HALF OF IL WILL BE SUN AND SUN NIGHT, AS THE  
UPPER WAVE AND ASSOCIATED SURFACE FEATURE MOVES THROUGH. THE  
STRENGTH OF THE SYSTEM IS STILL SOMEWHAT IN QUESTION. WIDESPREAD  
RAIN SHOULD OCCUR BUT THE EXACT AMOUNTS MAY STILL BE MONITORED  
THROUGH LATER FORECASTS.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)  
ISSUED AT 620 PM CDT WED JUN 29 2016  
 
VFR CONDITIONS SHOULD PREVAIL AT ALL TAF SITES NEXT 24HRS. CIRRUS  
FROM THE EARLY MORNING CONVECTION STILL COVERS MOST OF THE AREA  
AND WILL KEEP THAT GOING AT ALL SITES FOR TONIGHT AND INTO THE  
MORNING. MODELS DIFFER ON WHAT HAPPENS TOMORROW, BUT LOOKS LIKE  
ANOTHER MCS DEVELOPS OUT WEST AND REMNANTS OF THAT WILL MAKE ITS  
WAY INTO THE AREA, BRINGING BROKEN CU AROUND 6KFT INTO THE TAF  
SITES AROUND THE NOON HOUR. COULD BE SOME SHOWERS WITH THIS, BUT  
AGAIN, MODELS DIFFER SO WILL LEAVE OUT FOR NOW AND SEE WHAT  
HAPPENS TONIGHT. LIGHT AND VARIABLE WINDS WILL BE COMMON AGAIN  
TONIGHT AND INTO THE MORNING HOURS. THEN AS THE HIGH PRESSURE  
MOVES EAST, WINDS WILL BECOME MORE SOUTHERLY WITH SPEEDS LESS THAN  
10KTS.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SHORT TERM...BARNES  
LONG TERM...GOETSCH  
AVIATION...AUTEN  
 
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