099
FXUS63 KILX 181711
AFDILX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE LINCOLN IL
1111 AM CST WED DEC 18 2024
KEY MESSAGES
- LIGHT RAIN IS AFFECTING EAST CENTRAL ILLINOIS THIS MORNING, WITH
A 10-30% CHANCE OF LIGHT SNOW NORTH OF I-74.
- ANOTHER WEATHER SYSTEM WILL BRING SNOW TO PARTS OF THE REGION
THURSDAY NIGHT INTO FRIDAY MORNING, THOUGH CURRENT GUIDANCE
KEEPS MOST OF THE ACCUMULATIONS NORTH OF CENTRAL IL.
- SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THURSDAY TREND A FEW
DEGREES BELOW NORMAL FRI-SUN BEFORE REBOUNDING TO ABOVE NORMAL
FOR THE COMING HOLIDAY.
DISCUSSION
ISSUED AT 252 AM CST WED DEC 18 2024
SHOWERS HAVE MADE THEIR WAY ACROSS CENTRAL ILLINOIS OVERNIGHT INTO
THIS MORNING. THEY SHOULD COME TO AN END FOR OUR CWA AROUND SUNRISE.
THERE IS A BAND OF SNOW ASSOCIATED WITH AN AREA OF 700 MB
FRONTOGENETIC LIFT THAT HAS BEEN OVER PERFORMING ACROSS NORTHERN
IL OVERNIGHT. DETERMINISTIC CAMS AND GLOBAL MODELS HAVE NOT BEEN
MUCH HELP THIS MORNING WHEN IT COMES TO DETERMINING IF THIS BAND
WILL HOLD TOGETHER AND AFFECT OUR MOST NORTHERN COUNTIES. THEY
AREN'T HANDLING THE EVENT WELL OR INITIALIZING WELL. CURRENTLY,
TEMPERATURES IN NORTH OF I-72 IN OUR NORTHERN COUNTIES ARE RIGHT
AROUND THE FREEZING LEVEL, WHICH COULD MEAN A WINTRY MIX IF THE
BAND DOES REACH DOWN INTO OUR AREA. THE HREF 00Z.18 IS SHOWING A
10-30% CHANCE OF 0.1 INCH OF SNOW NORTH OF I-74.
AFTER THIS ROUND OF PRECIPITATION EXITS THE AREA BY LATE MORNING,
THERE WILL BE A LULL IN THE ACTIVITY THROUGH TONIGHT. BY TOMORROW
MORNING, A CLIPPER SYSTEM WILL MAKE ITS WAY INTO THE MIDWEST. THIS
BRINGS SOME MORE CHANCES FOR A RAIN/SNOW MIX OVERNIGHT THURSDAY
BEFORE SWITCHING OVER TO SNOW BY FRIDAY MORNING AS TEMPERATURES COOL
BEHIND THE ASSOCIATED COLD FRONT. THE EURO, NAM, AND GFS SHOW THE
SNOW STAYING BARELY NORTH OF THE CWA BUT SOME SNOW COULD CLIP OUR
NORTH COUNTIES ALONG AND NORTH OF I-74. THAT IS WHERE THE MAIN AREA
OF SNOW ACCUMULATION IS LOCATED. THERE IS SOME CONCERN FOR FREEZING
DRIZZLE SOUTH OF THE LOW TRACK WHERE LIFT IS PRESENT BUT MOISTURE IS
LIMITED.
FINALLY AFTER A VERY ACTIVE PERIOD, WE SEE A BREAK IN THE
PRECIPITATION LASTING THROUGH MONDAY MORNING. ANOTHER LOW PRESSURE
SYSTEM LOOKS TO BRING MORE RAIN TO CENTRAL AND SOUTHEASTERN
ILLINOIS, WITH TEMPERATURES BEING IN THE UPPER 30S TO LOW 40S THAT
DAY. CHANCES FOR PRECIPITATION CONTINUE INTO CHRISTMAS DAY
(WEDNESDAY).
TEMPERATURES REMAIN SEASONABLE OR SLIGHTLY ABOVE NORMAL THROUGH
THURSDAY NIGHT. BEHIND THE CLIPPER SYSTEM FRIDAY, TEMPERATURES COOL
INTO THE LOW 30S FOR HIGHS AND UPPER TEENS TO LOW 20S FOR LOWS. BY
SUNDAY, HOWEVER, A REBOUND TO ABOVE NORMAL TEMPERATURES LOOKS
LIKELY. CHRISTMAS IS 1 WEEK AWAY NOW. A "WHITE" CHRISTMAS IS LOOKING
LESS LIKELY AS HIGHS AND LOWS ARE FORECAST (CURRENTLY) TO BE ABOVE
FREEZING.
COPPLE
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1111 AM CST WED DEC 18 2024
TRICKY TAFS WITH RESPECT TO CEILING CATEGORY OVER THE NEXT 24
HOURS. CURRENTLY IFR HANGING ON FOR MOST CENTRAL IL TERMINALS,
THOUGH THESE WILL RISE TO MVFR EARLY THIS AFTERNOON. SATELLITE
TRENDS UPSTREAM (NORTHWEST) INDICATE PLENTY OF HOLES IN THE
OVERCAST, BUT PREDOMINANT MVFR CEILINGS INTO MN. GIVEN TYPICAL
TRENDS IN THE COOL SEASON, OPTED TO BE PESSIMISTIC WITH MVFR
CEILINGS FORECAST INTO THU MORNING, THOUGH PERIODS OF VFR WILL
LIKELY BE PRESENT THROUGH TONIGHT. NORTHWEST WINDS AT 10-14 KT
THIS AFTERNOON WILL PERIODICALLY GUST AROUND 20 KT, BEFORE GOING
LIGHT/VARIABLE LATER THIS EVENING AS HIGH PRESSURE MOVES OVERHEAD.
S/SSE WINDS TO INCREASE LATE THU MORNING AS THE MSLP GRADIENT
INCREASES ON THE BACK SIDE OF THE RIDGE.
25
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
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