888  
FXUS63 KILX 201140  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
640 AM CDT WED AUG 20 2014  
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 333 AM CDT WED AUG 20 2014  
 
STORMS HAVE DEVELOPED ALONG A BOUNDARY IN NORTHEAST MO AND SOUTHEAST  
IA EARLY THIS MORNING. THESE STORMS SHOULD MOVE INTO WESTERN AND  
SOUTHWEST IL IN THE NEXT SEVERAL HOURS. THESE COULD GET INTO WESTERN  
PARTS OF THE CWA SO WILL HAVE SOME CHANCE POPS IN THE WEST THIS  
MORNING. HOWEVER, ALL MODELS SEEM TO INDICATE THIS AREA WILL NOT  
TRAVEL VERY FAR AND SHOULD DISSIPATE DURING THE MORNING HOURS. THE  
ASSOCIATED BOUNDARY WILL THEN SLOWLY LIFT NORTHEAST AS A WARM FRONT  
THROUGH THE CWA, AND THOUGH CONVERGENCE ALONG THIS BOUNDARY WILL BE  
WEAK, SOME ISOLATED SHOWERS OR THUNDERSTORMS WILL REMAIN POSSIBLE IN  
THE EARLY AFTERNOON. BY LATE AFTERNOON AND INTO THE EVENING AND  
OVERNIGHT HOURS, THE WARM FRONT WILL REMAIN ACROSS THE CENTRAL PART  
OF THE CWA SO THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE  
DURING THE EVENING AND OVERNIGHT HOURS.  
 
TEMPERATURES WILL BE A FEW DEGREES WARMER THAN YESTERDAY, WITH SOME  
AREAS IN THE WEST AND SOUTH GETTING TO AROUND 90. OVERNIGHT LOWS  
WILL ALSO BE WARMER AS MOST OF THE CWA WILL BE IN THE WARM SECTOR  
OVERNIGHT.  
 

 
   
LONG TERM
 
(THURSDAY THROUGH TUESDAY)  
ISSUED AT 333 AM CDT WED AUG 20 2014  
 
POSITION OF THE BOUNDARY AFTER LIFTING THROUGH THE FA TODAY AND  
TONIGHT WILL HAVE A SIGNIF IMPACT ON THE LOCATION OF THE SHOWERS AND  
THUNDERSTORMS. THOUGH MOST RECENT MODELS ARE LIFTING THE BOUNDARY  
FURTHER TO THE NORTHEAST, SOME CHANCE POPS THURS AND SLIGHT CHANCE  
POPS REMAIN IN PLACE AT LEAST OVER THE NORTHEASTERN PORTIONS OF THE  
CWA FROM THURSDAY NIGHT THROUGH FRIDAY NIGHT. POPS INCREASING  
SOMEWHAT FOR SATURDAY AS MODELS ARE COLLAPSING THE RIDGE SOMEWHAT AS  
A WAVE MOVES OVER THE RIDGE AND INTO THE OHIO RIVER VALLEY. THOUGH  
THE PRECIP CHANCES ARE SCATTERED AT BEST AND LOW CONFIDENCE...THE  
MODELS HAVE BEEN VERY PERSISTENT WITH THE VERY HOT TEMPERATURES FOR  
SOME SUMMER LIKE CONDITIONS THAT ARE WELL ABOVE NORMAL FOR THIS TIME  
OF YEAR. MODELS HAVE ALSO SHOWN CONSISTENCY WITH 850 MB TEMPS IN  
THE 19-25C RANGE THROUGH SUNDAY. THIS WILL DRIVE THE TEMPS INTO THE  
UPPER 80S/LOWER 90S WITH HEAT INDICES IN THE UPPER 90S/LOW 100S.  
FORECAST DWPTS INTO THE LOW TO MID 70S MAY BE OVER REPRESENTING LLVL  
RH ENHANCEMENT FROM WIDESPREAD PRECIP IN THE MODELS THAT MAY NOT  
QUITE COME TO FRUITION AS WIDESPREAD. TODAYS HEAT INDICES ARE MORE  
BORDERLINE FOR HEAT ADVISORY CRITERIA...BUT FAR MORE LIKELY TO SEE  
FROM THURSDAY INTO SUNDAY WITH SUBSEQUENT FORECASTS, SHOULD THE  
TREND CONTINUE. INTO THE EXTENDED, DAY 7/JUST INTO DAY 8, MODELS  
ACTUALLY BEGINNING TO DIVERGE INTO A SOLUTION TO BREAK DOWN THE  
RIDGE WITH AN UPPER SYSTEM PUSHING A RETURN OF PRECIP IN FOR TUES  
NIGHT INTO WED.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)  
ISSUED AT 640 AM CDT WED AUG 20 2014  
 
SHOWERS AND THUNDERSTORMS ARE MOVING ACROSS THE WESTERN PORTION OF  
THE STATE, BUT NOT CURRENTLY AFFECTING ANY OF THE TAF SITES ON  
STATION. HOWEVER, THEY COULD AFFECT SPI SO WILL HAVE VCTS TO START  
THE TAF. BMI HAS HAD SOME FOG THIS AM SO WILL HAVE A TEMPO GROUP  
FOR THAT. IN ADDITION, CMI HAS BEEN DONE WITH 1/4SM VV002 ALL  
NIGHT. BELIEVE THIS FOG IS NOT VERY THICK, GIVEN THE TRENDS OF THE  
OBSERVATIONS FROM SITES THAT HAVE EXPERIENCED FOG THIS MORNING. BY  
14-15Z ALL SITES SHOULD BE VFR WITH CU DEVELOPING DURING THE DAY  
AND HIGH CIRRUS OVERSPREADING FROM THE STORMS WEST OF THE AREA.  
THESE CLOUDS SHOULD DISSIPATE TOWARD THE EVENING HOURS AND THEN  
JUST LEAVE SCATTERED AC AROUND 12KFT AT ALL SITES FOR THE EVENING.  
THEN OVERNIGHT HIGH SC DEVELOPS OVER THE AREA AND SHOULD BECOME  
BROKEN. COULD BE SOME PCPN WITH THIS AS THE CLOUDS WILL BE  
ASSOCIATED WITH THE WARM FRONT THAT LIFTS THROUGH THE AREA TODAY,  
BUT BELIEVE ONLY VCSH WARRANTED AT THIS POINT. LATER FORECASTS CAN  
GET A BETTER HANDLE ON THINGS LATER TODAY. WINDS WILL BECOME  
SOUTHWESTERLY DURING MOST OF THE DAY AND THEN SOUTHERLY TONIGHT.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SHORT TERM...AUTEN  
LONG TERM...HJS  
AVIATION...AUTEN  
 
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