084  
FXUS63 KILX 201155  
AFDILX  
 
AREA FORECAST DISCUSSION...UPDATED AVIATION  
NATIONAL WEATHER SERVICE LINCOLN IL  
555 AM CST FRI DEC 20 2024  
   
KEY MESSAGES
 
 
- LIGHT SNOW IS EXPECTED THROUGH LATE THIS MORNING. A LIGHT  
DUSTING OF SNOW IS POSSIBLE NORTH OF A SPRINGFIELD TO EFFINGHAM  
LINE, WITH ACCUMULATIONS UP TO 1 INCH MOST LIKELY NORTH OF I-74.  
 
- NORTH-NORTHWEST WINDS WILL BE BRISK TODAY WITH GUSTS UP TO 35  
MPH THROUGH THIS AFTERNOON.  
 
- COOL AND DRY WEATHER THIS WEEKEND WILL BE REPLACED BY MILD AND  
UNSETTLED CONDITIONS BEGINNING NEXT WEEK.  
 

 
   
DISCUSSION
 
 
ISSUED AT 354 AM CST FRI DEC 20 2024  
 
SURFACE LOW PRESSURE IS CENTERED OVER NORTHEAST ILLINOIS/NORTHERN  
INDIANA THIS MORNING WITH A COLD FRONT STRETCHED SOUTH OF THERE  
THROUGH WESTERN INDIANA AND KENTUCKY. BREEZY AND COOL CONDITIONS  
HAVE FILLED IN BEHIND THE FRONT WITH TEMPERATURES IN THE UPPER 20S  
TO LOW 30S. AN UPPER SHORTWAVE TROUGH CURRENTLY CENTERED OVER  
EASTERN IOWA WILL DIVE SOUTHEAST THIS MORNING, BRINGING A PERIOD OF  
LIGHT SNOW TO MOST NORTH OF I-70. SNOW ACCUMULATIONS LOOK RELATIVELY  
LIGHT WITH THE 20.00Z HREF SHOWING DECENT PROBABILITIES FOR A  
DUSTING NORTH OF A SPRINGFIELD TO EFFINGHAM LINE, WITH A 30-50%  
CHANCE FOR AT LEAST 0.5 INCH NORTH OF I-74. COOLER TEMPERATURES WILL  
FAVOR A FLUFFIER SNOW VARIETY WITH BREEZY WINDS LEADING TO BLOWING  
OF FALLING SNOW. THOSE TRAVELING SHOULD BE PREPARED FOR SLIPPERY  
ROADS AND REDUCED VISIBILITIES.  
 
SNOW WILL COME TO AN END LATER THIS MORNING, WITH SOME LINGERING  
ACTIVITY CONTINUING THIS AFTERNOON CLOSER TO THE INDIANA BORDER.  
SURFACE HIGH PRESSURE WILL SINK INTO THE PLAINS STATES, ACTING TO  
PUSH THE SURFACE LOW FURTHER EAST OF HERE. SURFACE WINDS WILL VEER  
TO THE NORTH, SETTING UP A LAKE-EFFECT SNOW BAND OVER LAKE MICHIGAN.  
IN FACT, THE FETCH OF THE WIND OVER THE LAKE (N-NE) WILL BRING SOME  
LIGHT SNOW OR FLURRIES TO THOSE IN FAR EAST-CENTRAL ILLINOIS THROUGH  
THIS AFTERNOON. LITTLE TO NO ACCUMULATION IS EXPECTED WITH THE LAKE  
ENHANCED ACTIVITY.  
 
THE SURFACE RIDGE WILL INCH CLOSER TO THE AREA TONIGHT, ALLOWING  
WINDS TO BEGIN RELAXING. LOW STRATUS WILL BE SLOW TO DEPART TODAY,  
BUT SUBSIDENCE TIED TO THE SURFACE HIGH/UPPER RIDGE SHOULD AID IN  
SCATTERING THINGS OUT BY THIS EVENING OR OVERNIGHT. A FEW MID-LEVEL  
CLOUDS WILL FILL IN BEHIND IT, BUT SHOULD BE THIN ENOUGH TO ALLOW  
TEMPERATURES TO DROP INTO THE TEENS TO LOW 20S OVERNIGHT. SURFACE  
RIDGING WILL KEEP THINGS COOL AND DRY THROUGH SATURDAY NIGHT WITH  
SOUTHERLY RETURN FLOW SHAPING UP FOR SUNDAY AS THE HIGH SPREADS INTO  
THE EASTERN US.  
 
MILD AND UNSETTLED WEATHER SHAPES UP GOING INTO THE HOLIDAY WEEK.  
TEMPERATURES THROUGH THE WEEK WILL GRADUALLY WARM WITH HIGHS  
AVERAGING ABOUT 5-10 DEGREES ABOVE NORMAL THROUGH WEDNESDAY, THEN  
APPROACHING 15 DEGREES ABOVE NORMAL BY THE END OF THE WEEK. DAILY  
PRECIPITATION CHANCES WILL ACCOMPANY THE MILDER TEMPERATURES WITH  
THE FIRST WAVE DROPPING A COLD FRONT THROUGH THE AREA ON MONDAY.  
THIS FRONT WILL STALL OUT NEAR THE OHIO VALLEY, KEEPING  
PRECIPITATION CHANCES IN PARTS OF THE AREA THROUGH AT LEAST  
TUESDAY. SOME DIFFERENCES REMAIN BEYOND THEN, BUT A SERIES OF  
FRONTAL SYSTEMS MAY REGENERATE ACTIVITY ALONG THE FRONT AS IT GETS  
PUSHED BACK NORTHWARD FROM CHRISTMAS DAY (WED) THROUGH THE END OF  
THE WEEK. THE NBM SPLATTERS AT LEAST 20% POPS THROUGH THE ENTIRE  
WEEK WITH FURTHER REFINEMENTS EXPECTED IN FUTURE UPDATES.  
 
NMA  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)  
ISSUED AT 555 AM CST FRI DEC 20 2024  
 
LIGHT SNOW IS SPREADING SOUTH ACROSS THE AREA THIS MORNING,  
IMPACTING MOST AIRFIELDS WITH MVFR TO IFR CEILINGS AND VISIBILITIES.  
SNOW EXITS LATER THIS MORNING, THOUGH MVFR CEILINGS WILL STICK  
AROUND THROUGH AT LEAST 00-03Z. NORTHWEST WINDS WITH GUSTS UP TO 30  
KTS WILL CONTINUE THROUGH THIS AFTERNOON BEFORE LESSENING THIS  
EVENING AND GRADUALLY VEER TO THE NORTH.  
 
NMA  
 

 
   
ILX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
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