185  
FXUS63 KILX 232359  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
659 PM CDT WED MAY 23 2018  
   
SHORT TERM
 
(THIS EVENING THROUGH THURSDAY NIGHT)  
ISSUED AT 300 PM CDT WED MAY 23 2018  
 
FAIR AND DRY WEATHER EXPECTED TO CONTINUE ACROSS CENTRAL AND  
SOUTHEAST IL THROUGH THURSDAY NIGHT. UPPER LEVEL RIDGE OVER THE MS  
RIVER VALLEY AND IL THROUGH THURSDAY ALONG WITH SURFACE HIGH  
PRESSURE RIDGE SPREADING ACROSS THE SOUTHERN GREAT LAKES AND INTO  
THE MID ATLANTIC STATES, WILL KEEP IT DRY WITH FAIR SKIES. FEW TO  
SCATTERED CUMULUS CLOUDS WITH BASES OF 4-5K FT FROM GALESBURG TO  
SPRINGFIELD WEST WILL DIMINISH AND/OR RETREAT TO THE WEST LATE  
THIS AFTERNOON AND EARLY EVENING WITH EAST WINDS BRINGING IN DRIER  
AIR AS DEWPOINTS SLIP INTO THE 50S. DRIER AIR WILL ALSO LIMIT  
PATCHY SHALLOW GROUND FOG FORMATION TOWARD DAYBREAK AND LEFT OUT  
OF FORECAST. LOWS OVERNIGHT IN THE LOWER 60S, WITH SOME UPPER 50S  
OVER DRIER AIR (DEWPOINTS IN THE LOWER 50S) FROM BLOOMINGTON AND  
CHAMPAIGN NE. TEMPS CURRENTLY IN THE LOW TO MID 80S ACROSS CWA.  
EXPECT TEMPS TO RISE A FEW DEGREES HIGHER TOMORROW WITH HIGHS IN  
THE MID TO UPPER 80S WITH AMPLE SUNSHINE, WARMEST IN WESTERN CWA  
WHERE 850 MB TEMPS AROUND 16C. HUMIDITY LEVELS STAY FAIR LOW YET  
ON THU WITH DEWPOINTS IN THE MID TO UPPER 50S CENTRAL AND EASTERN  
IL, AND LOWER 60S IN WESTERN CWA. LOWS THU NIGHT OF 60-65F, WITH  
COOLEST READINGS AROUND 60F IN EAST CENTRAL IL AND MILDEST WESTERN  
CWA.  
   
LONG TERM
 
(FRIDAY THROUGH WEDNESDAY)  
ISSUED AT 300 PM CDT WED MAY 23 2018  
 
AN UPPER LEVEL TROF OVER THE NORTHWEST US AND NORTHERN ROCKIES TO  
OPEN UP/WEAKEN AS IT MOVES EAST TO WI AND THE IA/IL BORDER BY  
SUNSET FRIDAY. SURFACE HIGH MOVES OFF THE MID ATLANTIC STATES  
FRIDAY WITH A SOUTHERLY FLOW BRINGING VERY WARM AND STARTING TO  
BRING IN MORE HUMID AIR. HIGHS FRIDAY IN THE UPPER 80S WITH  
DEWPOINTS ELEVATING INTO THE LOW TO MID 60S. ISOLATED SHOWERS AND  
THUNDERSTORMS POSSIBLE FROM I-55 WEST FRIDAY AFTERNOON/EVENING.  
ISOLATED CONVECTION POSSIBLE IN EASTERN IL TOO OVERNIGHT FRIDAY  
NIGHT. HAVE 20-30% CHANCE OF CONVECTION ON SATURDAY AS WEAKENING  
UPPER LEVEL TROF MOVES THROUGH, AND INTO THE OHIO RIVER VALLEY BY  
SAT NIGHT. HAVE 30% POPS FROM I-55 EAST BY SAT AFTERNOON WITH 20%  
WEST OF I-55 ON SATURDAY. HIGHS SAT IN THE UPPER 80S TO NEAR 90F  
WITH AFTERNOON HEAT INDICES OF 90-95F.  
 
ISOLATED CONVECTION COULD LINGER IN SOUTHEAST IL SAT NIGHT AND  
SUNDAY WITH ANOTHER VERY WARM AND RATHER HUMID DAY WITH HIGHS IN  
THE UPPER 80S AND LOWER 90S AND AFTERNOON HEAT INDICES OF 90-95F.  
MODELS HAVE TRENDED DRIER SUNDAY NIGHT THROUGH MONDAY AS UPPER  
LEVEL RIDGE BUILDS BACK OVER IL. SUMMERLIKE HEAT AND HUMIDITY TO  
LIKELY PREVAIL THROUGH NEXT WED WITH HIGHS IN THE UPPER 80S TO  
NEAR 90F. A WEAK CUTOFF UPPER LEVEL LOW LIFTING SLOWLY NORTHWARD  
OVER THE GULF OF MEXICO AND INTO THE SOUTHEAST STATES BY MIDDLE OF  
NEXT WEEK COULD RETURN ISOLATED CONVECTION TO SOUTHEAST IL BY TUE  
AFTERNOON AND OVER THE CWA BY NEXT WED.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)  
ISSUED AT 655 PM CDT WED MAY 23 2018  
 
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN ACROSS THE CENTRAL  
ILLINOIS TERMINALS THROUGH THE 00Z TAF VALID TIME. LIGHT/VARIABLE  
WINDS TONIGHT WILL TREND SOUTHEAST ON THURSDAY. LITTLE TO NO CLOUD  
COVER IS EXPECTED, AND ANY CLOUDS SHOULD REMAIN WELL INTO THE VFR  
CATEGORY.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SHORT TERM...07  
LONG TERM...07  
AVIATION...BAK  
 
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