572  
FXUS63 KILX 222052  
AFDILX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LINCOLN IL  
252 PM CST SAT NOV 22 2014  
   
SHORT TERM
 
(TONIGHT)  
ISSUED AT 252 PM CST SAT NOV 22 2014  
 
WEAKENING 1031 MB HIGH PRESSURE DRIFTING OFF EASTERN NC SHORE WHILE  
STRONG AND DEEPENING 985 MB LOW MOVING EAST INTO SW SASKETCHEWAN.  
THIS WAS GIVING A TIGHT PRESSURE GRADIENT OVER CENTRAL AND SOUTHEAST IL  
THIS AFTERNOON WITH VERY BREEZY SSW WINDS 12 TO 22 MPH AND GUSTS OF  
25 TO 30 MPH. SSW WINDS ADVECTING IN MUCH MILDER AND MORE MOIST AIR  
FROM WESTERN GULF OF MEXICO WITH TEMPERATURES IN THE MID 50S TO LOWER 60S  
(WARMEST SW AREAS WITH MOUNT CARMEL AIRPORT AT 64F) AND DEWPOINTS IN  
THE MIDDLE TO UPPER 40S. CLOUDY SKIES ACROSS MUCH OF CENTRAL IL WITH  
SOME BREAKS IN CLOUDS SE OF I-70 IN SOUTHEAST IL. ISOLATED LIGHT  
RAIN SHOWERS OVER EASTERN IL THIS AFTERNOON WHILE SHOWERS MORE  
NUMEROUS OVER SW IL FROM I-64 SOUTH INTO SOUTHERN MO ALONG AND SE OF  
I-44 WHERE A FEW THUNDERSTORM WERE A FEW HOURS AGO. MID LEVEL  
MOISTURE SPREADS NORTHWARD TONIGHT ACROSS AREAS SE OF THE IL RIVER  
AND THIS TO INCREASE CHANCES OF LIGHT RAIN SHOWERS THOUGH RAINFALL  
AMOUNTS WILL BE LIGHT DUE TO WEAK LIFT/FORCING. ALSO HAVE PATCHY  
DRIZZLE WITH LOWER CLOUDS OVER IL RIVER VALLEY TONIGHT AND AREAS OF  
FOG OVERNIGHT (CURRENTLY GETTING FOG OVER PARTS OF NW IL AND SE IA).  
WENT A FEW DEGREES ABOVE SIMILAR MET/MAV GUIDANCE FOR LOWS TONIGHT  
IN THE MID TO UPPER 40S DUE TO CLOUD COVER AND SOUTHERLY WINDS OF  
10-15 MPH AND GUSTS TO 20 MPH ESPECIALLY THIS EVENING.  
 

 
   
LONG TERM
 
(SUNDAY THROUGH SATURDAY)  
ISSUED AT 252 PM CST SAT NOV 22 2014  
 
THE VIGOROUS SHORT WAVE, LIFTING OUT OF THE SOUTHERN PLAINS WILL  
PHASE WITH A NORTHERN STREAM SYSTEM TOMORROW; THE RELATED SURFACE  
SYSTEM WILL STRENGTHEN OVER THE CWA AND LIFT NORTHEAST EAST TOMORROW  
NIGHT THROUGH MONDAY. THE ASSOCIATED COLD FRONT WITH THIS SYSTEM  
WILL MOVE THROUGH THE AREA MONDAY NIGHT AND BRING THE RETURN TO  
COLDER AIR IN THE REGION FOR THE BEGINNING OF THE COMING WEEK. THIS  
SYSTEM IS THE MAIN CHALLENGE WITH THIS FORECAST PACKAGE THIS  
AFTERNOON. THE RESULTING WEATHER WITH THIS SYSTEM WILL BE FOR MOSTLY  
RAIN ACROSS THE WHOLE AREA TOMORROW WITH THE POSSIBILITY OF ISOLATED  
THUNDERSTORMS IN SOUTHEASTERN IL, ALONG AND SOUTH OF I-70, FOR  
TOMORROW AFTERNOON THROUGH TOMORROW EVENING. THE DYNAMICS OF THIS  
SYSTEM DO NOT LOOK VERY STRONG, SO SEVERE STORMS ARE NOT EXPECTED IN  
SOUTHEAST ILLINOIS TOMORROW AFTERNOON OR EVENING. AREAS ACROSS THE  
NORTH WILL SEE THE AREAS OF FOG CONTINUING THROUGH TOMORROW AND  
TOMORROW NIGHT. THE FOG WILL DISSIPATE IN THE NORTH ONCE THE LOW  
PRESSURE AREA MOVES NORTHEAST AND THE COLD FRONT MOVES THROUGH THE  
AREA, TOMORROW NIGHT. THE COLDER AIR THAT MOVES IN SUNDAY NIGHT AND  
MONDAY, AS THE SYSTEM DEEPENS AND MOVES NORTHEAST, WILL BRING A  
CHANGE TO THE P-TYPE, RESULTING IN RAIN MIXING WITH SNOW IN THE WEST  
SUNDAY NIGHT, AND THEN BECOMING ALL SNOW BY MONDAY. SNOWFALL  
ACCUMULATIONS WILL BE A HALF INCH OR LESS; SINCE THE PCPN WILL BE  
ENDING AS THE SYSTEM MOVES NORTHEAST.  
 
TEMPS WILL REMAIN WARM TOMORROW BUT THEN FALL FROM TOMORROW NIGHT  
THROUGH MONDAY NIGHT. TEMPS ON MONDAY WILL BE STEADY OR SLOWLY  
FALLING IN THE AFTERNOON, WITH THE 24HR HIGHS LIKELY BEING AROUND  
MIDNIGHT TOMORROW NIGHT, AND LOWS LATE MONDAY EVENING.  
 
THE REMAINDER OF THE FORECAST PERIOD, THROUGH SATURDAY, WILL BE  
RELATIVELY DRY. HOWEVER, THE MODELS ARE BRINGING IN A WEAK CLIPPER  
SYSTEM WED THROUGH THUR, THAT WILL BRING A CHANCE OF SNOW TO THE  
NORTHERN THIRD OF THE CWA. MODELS ARE FAIRLY CONSISTENT WITH THE  
LOCATION OF THE TRACK OF THE LOW PRESSURE AREA, BUT DIFFER ON  
TIMING. SO WILL STILL WITH A BLEND OF THE TWO MODELS AND KEEP THE  
CHANCE OF SNOW WED AND WED NIGHT, AS WITH PREVIOUS FORECAST; AND  
THEN HAVE A CHANCE IN THE NORTHEAST PARTS FOR THUR TO ACCOMMODATE  
THE SLOWER TIMING OF THE ECMWF.  
 
TEMPS WILL WARM SOME ON WED, AHEAD OF THE CLIPPER SYSTEM, BUT THEN  
TURN COLD AGAIN AFTER THE SYSTEM MOVES THROUGH AND COLDER AIR  
ADVECTS INTO THE REGION AGAIN.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)  
ISSUED AT 1155 AM CST SAT NOV 22 2014  
 
MVFR CEILINGS AT PIA AND BMI MOST OF THIS MORNING (JUST LIFTED TO  
VFR AT PIA) WHILE VFR CEILINGS ALONG I-72 AT MIDDAY. MEANWHILE  
ISOLATED TO SCATTERED SHOWERS HAD SHIFTED SE OF THE CENTRAL IL  
AIRPORTS AT LATE MORNING. HRRR SHOWS MVFR CEILINGS 2-3K FT  
POSSIBLE AT TIMES OVER CENTRAL IL THIS AFTERNOON ESPECIALLY AT PIA  
AND BMI, AND THIS MODEL SHIFTS THESE LOWER CEILINGS ALONG WITH FOG  
FURTHER NORTH OF CENTRAL IL THIS EVENING. WAS MORE PESTIMISTIC  
WITH KEEPING MVFR CEILINGS AND VSBYS AROUND TONIGHT AND EVEN LOWER  
IFR CEILINGS AT PIA AND BMI SUNDAY MORNING. RAIN SHOWERS TO BECOME  
MORE LIKELY LATER THIS EVENING/OVERNIGHT WITH BEST CHANCES  
SHIFTING INTO IL RIVER VALLEY BY PIA LATE TONIGHT AND SUNDAY  
MORNING. BREEZY SSW WINDS 12-17 KTS WITH GUSTS 18-25 KTS INTO THIS  
EVENING TO VEER SSE SUNDAY MORNING AND STILL GUST AGAIN TO 18-23  
KTS. KEPT LLWS IN TAFS AGAIN TONIGHT UNTIL MID MORNING SUNDAY  
WITH 2K FT SW WINDS OF 40 KTS.  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
SHORT TERM...07  
LONG TERM...AUTEN  
AVIATION...07  
 
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