484
FXUS63 KILX 051742
AFDILX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE LINCOLN IL
1142 AM CST MON JAN 5 2026
KEY MESSAGES
- MILD CONDITIONS ARE FORECAST DURING THE WORK WEEK WITH DAILY
HIGHS GENERALLY IN THE 50S. SEASONABLY COOL WEATHER WILL RETURN
THIS WEEKEND, WITH A 40-60% CHANCE OF HIGH TEMPERATURES BELOW
FREEZING BY SUNDAY.
- BENEFICIAL RAIN IS FORECAST (70-90% CHANCE) THURSDAY INTO FRIDAY.
CHANCES FOR MORE THAN A HALF INCH OF RAINFALL ARE AS HIGH AS
60-70% IN EAST-CENTRAL IL, WHERE THE ONGOING DROUGHT IS MOST
SEVERE.
DISCUSSION
ISSUED AT 149 AM CST MON JAN 5 2026
***** CLOUDY BUT MILD THROUGH TOMORROW *****
EARLY MONDAY MORNING, 10-15 MPH SOUTH-SOUTHWEST WINDS WERE HOLDING
TEMPERATURES IN THE LOW TO MID 30S ACROSS CENTRAL AND SOUTHEAST IL
AS A SURFACE LOW PASSES TO OUR NORTH IN WISCONSIN AND LOWER
MICHIGAN. ALREADY, SCATTERED HIGH CLOUDS ARE RETURNING ON WESTERLIES
STREAMING OFF THE PACIFIC, THOUGH THESE SHOULDN'T HAVE TOO BIG AN
IMPACT ON HIGHS TODAY WHICH, THANKS TO RIDGING EXPANDING INTO THE
REGION, SHOULD CLIMB INTO THE UPPER 40S TO LOW 50S. ENERGY
EMANATING FROM THE FOUR CORNERS REGION WILL RESULT IN A LEE
CYCLONE WHICH WILL MEANDER INTO NORTHERN IL TONIGHT INTO TOMORROW
MORNING. THIS WILL KEEP TEMPERATURES MILD TONIGHT, BUT MAY ALSO
RESULT IN SOME PATCHY FOG OR DRIZZLE. IN GENERAL, GUIDANCE HAS
BACKED OFF ON THE DRIZZLE POTENTIAL FOR OUR AREA, THOUGH, AS
MOISTURE CONVERGENCE WITH THE LOW IS TO OUR NORTH, WRAP AROUND
MOISTURE IS TO OUR WEST, AND WARM ADVECTION LIFT IS FOCUSED TO OUR
EAST. IN ANY CASE, HREF SUGGESTS MEDIUM-HIGH CONFIDENCE (60-80%
CHANCES) LOW CLOUDS WILL STICK AROUND THROUGH THE DAY TOMORROW
NORTH OF I-70 WHERE TEMPERATURES MAY RUN A BIT COOLER (UPPER 40S,
VS UPPER 50S TO AROUND 60 SOUTH OF I-70) AND WEST WINDS WILL GUST
TO 20+ MPH.
***** RAIN LIKELY (70-90% CHANCE) LATE WEEK *****
CONDITIONS ARE FORECAST TO REMAIN MILD THROUGH AT LEAST THURSDAY,
AFTER WHICH TIME RIDGING WILL BEGIN TO SHIFT EAST AS A MORE POTENT
UPPER LEVEL TROUGH APPROACHES. GLOBAL MODELS AND THEIR RESPECTIVE
ENSEMBLES CONTINUE TO DIFFER IN THE EVOLUTION AND TRACK OF A SURFACE
LOW DEVELOPING IN THE LEFT EXIT REGION OF A 90+ KT 500MB JET STREAK,
HOWEVER THE TREND HAS BEEN A BIT SLOWER AND FURTHER WEST; THIS IS
REFLECTED IN NBM'S MAXT FORECAST FOR FRIDAY, WHICH CLIMBED 4-7
DEGREES (HIGHEST IN OUR SOUTHEAST) FROM ITS LAST CYCLE. AS A
CONSEQUENCE, RAIN CHANCES HAVE COME UP CONSIDERABLY OVER OUR AREA,
WITH TWO POSSIBLE WAVES: ONE THURSDAY INTO THURSDAY NIGHT, AND
ANOTHER WITH THE MAIN TROUGH/COLD FRONT FRIDAY INTO FRIDAY NIGHT.
BETWEEN THESE TWO WAVES, RAW ENSEMBLE GUIDANCE (LREF) GIVES 60-70%
CHANCES FOR MORE THAN A HALF INCH OF RAINFALL OVER EAST-CENTRAL AND
SOUTHEAST IL, WITH THOSE PROBABILITIES TAPERING TO 30-50% WEST OF
ROUGHLY I-55; CHANCES FOR OVER AN INCH ARE GENERALLY 20-35% EAST OF
I-55, HIGHEST IN SOUTHEAST IL WHERE INSTABILITY IS MOST LIKELY TO BE
HIGH ENOUGH FOR SOME THUNDERSTORMS. ON THE TOPIC, UNCERTAINTY
REMAINS HIGH IN WHETHER A SEVERE WEATHER RISK WILL MATERIALIZE OVER
US, WITH TWO PERPLEXING FACTORS: (1) THE POSSIBLE DEVELOPMENT OF A
FORERUNNING SHORTWAVE THURSDAY (NIGHT), WHICH COULD LEAVE OUR AREA
LESS WARM AND UNSTABLE GOING INTO FRIDAY; AND (2) THE SLOWER,
FURTHER WEST SURFACE LOW ON FRIDAY, WHICH COULD BRING THE TRIPLE
POINT THROUGH A PORTION OF OUR AREA - INCREASING THE RISK FOR SEVERE
STORMS. AT THIS POINT, IT WOULDN'T BE SURPRISING TO GET LOCALLY
SEVERE HAIL WITH ELEVATED STORMS ALONG THE WARM FRONT WITH EITHER
WAVE, BUT IF WE DESTABILIZE MORE THAN CURRENTLY FORECAST AHEAD OF
THE SURFACE LOW ON FRIDAY, ALL HAZARDS WOULD BE PLAUSIBLE; BASED ON
VARIOUS ML FORECASTS AND ENSEMBLE SURFACE LOW TRACKS, THAT OUTCOME
SEEMS MOST LIKELY (5-15% CHANCE) SOUTHEAST OF A ROUGHLY SHELBYVILLE
TO DANVILLE LINE, BUT AGAIN LOTS IS SUBJECT TO CHANGE BETWEEN NOW
AND THEN. STAY TUNED.
***** TURNING SEASONABLY COOL AGAIN THIS WEEKEND *****
BEHIND THE COLD FRONT, CONDITIONS WILL TURN SEASONABLY BREEZY THEN
COOLER SATURDAY INTO SUNDAY. NBM SUGGESTS A 40-50% CHANCE OF HIGH
TEMPERATURES IN THE 20S ON SUNDAY. IN ADDITION, ABOUT 15-30%
(HIGHEST NORTH) OF LREF GUIDANCE IS ADVERTISING MEASURABLE SNOW FROM
WRAP AROUND MOISTURE SATURDAY EVENING-NIGHT, THOUGH FORTUNATELY ONLY
A COUPLE MEMBERS (OUT OF 100) ARE SHOWING ACCUMULATIONS HIGHER THAN
AN INCH AS A DRIER AIRMASS GETS PULLED SOUTHEAST INTO OUR AREA.
BUMGARDNER
AVIATION
(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1142 AM CST MON JAN 5 2026
LOW PRESSURE WILL TRACK ACROSS NORTHERN ILLINOIS TONIGHT...BRINGING
LOW CLOUDS AND DRIZZLE TO THE AREA. LATEST CAMS MAINTAIN VFR CONDITIONS
UNTIL MIDNIGHT, THEN CEILINGS/VISBYS DETERIORATE OVERNIGHT. BASED ON
HRRR/RAP OUTPUT, HAVE INTRODUCED MVFR AT KPIA BY 08Z THEN FURTHER
EAST TO KBMI/KDEC/KCMI BY 10Z. ONCE THE WAVE PASSES, THE DRIZZLE
WILL COME TO AN END FROM WEST TO EAST BY TUESDAY MORNING: HOWEVER,
LOW CLOUDS WILL PERSIST THROUGH 18Z. WINDS WILL INITIALLY BE S/SW
AT 5-10KT THIS AFTERNOON, THEN WILL TEMPORARILY BACK TO SE TOWARD
SUNSET. AS THE LOW APPROACHES, WINDS WILL BECOME SW LATE THIS
EVENING, THEN WILL VEER TO W AND INCREASE TO 10-15KT AFTER FROPA
BY MID-MORNING MONDAY.
BARNES
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
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