496
FXUS63 KIWX 241845
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
145 PM EST WED DEC 24 2025
KEY MESSAGES
- RAIN AND FOG DEVELOPING OVERNIGHT. DRYING OUT THURSDAY BUT
REMAINING CLOUDY.
- A PERIOD OF FREEZING RAIN IS EXPECTED FRIDAY MORNING NEAR THE
INDIANA-OHIO-MICHIGAN STATE LINES. WARM ENOUGH ELSEWHERE FOR
"PLAIN" RAIN.
- REMAINING MILD THROUGH THE REST OF THIS WEEK. SHARPLY COLDER
STARTING MONDAY.
DISCUSSION
ISSUED AT 144 PM EST WED DEC 24 2025
ABUNDANT CLOUD COVER THIS AFTERNOON AHEAD OF A WARM FRONT CURRENTLY
ACROSS FAR SOUTHERN IL AND IN. THIS WARM FRONT SLOWLY LIFTS NORTH
THIS EVENING AND, AMID MODEST ISENTROPIC ASCENT (295K) AND AMPLE LOW-
LEVEL MOISTURE, A BRIEF PERIOD OF RAIN IS EXPECTED OVERNIGHT
ALONG WITH AT LEAST PATCHY FOG. TEMPERATURES TONIGHT WILL BE IN
THE MID-30S TO NEAR 40, WITH THE EXCEPTION OF HILLSDALE AND
BRANCH COUNTIES WHERE TEMPERATURES MAY HOLD AT 32. GIVEN THE
ANTICIPATED RAIN DURATION OF LESS THEN 3 HOURS, MARGINAL
TEMPERATURE PROFILES AND A SOUTHERN PUSH OF DRY AIR OVERNIGHT,
FREEZING RAIN CONCERNS ARE MINIMAL. LOW LEVEL MOISTURE MAY
BECOME POOLED ALONG THE WARM FRONT TONIGHT, FURTHER TRAPPED BY A
DEVELOPING INVERSION RESULTING IN FOG PRIMARILY SOUTH OF US 30.
MEDIUM CONFIDENCE ON FOG DURATION GIVEN THE INCOMING DRY AIR.
FOG MAY BE MOST PROLONGED TOWARD CENTRAL IN.
ATTENTION THEN TURNS TO THE FREEZING RAIN RISK FOR A PORTION OF
OUR AREA FRIDAY MORNING. THE WARM FRONT ADVANCES NORTHWARD YET
AGAIN WITH STOUT WARM AIR AND MOISTURE ADVECTION. THIS IS AT
ODDS WITH SLOWLY-RETREATING SURFACE HIGH PRESSURE ALONG THE
ONTARIO-QUEBEC BORDER. COOL EASTERLY FLOW PROVIDES REINFORCING
COLD AIR TO THE LOW-LEVELS IN CONTRAST TO A WELL DEVELOPED
WARM- NOSE ALOFT. COMPARED TO YESTERDAY, GUIDANCE DID COME IN
SLIGHTLY WARMER THAN 24 HOURS AGO, BUT NOT ENOUGH TO COMPLETELY
DISCOUNT A FZRA RISK. THUS, WE CONTINUE TO MENTION THE RISK OF
FZRA FOR THOSE NEAR THE MI-OH-IN LINES. DURATION OF UP TO 6
HOURS COULD CERTAINLY CAUSE AREAS OF SLIPPERY TRAVEL. ADDITIONAL
MODEL RUNS WILL ALLOW US TO FINE TUNE THE FORECAST FURTHER OVER
THE NEXT 24 HOURS.
AN UPPER-LEVEL RIDGE CENTERED OVER THE GULF COAST WILL CONTINUE TO
PROVIDE GENERALLY MILD CONDITIONS THROUGH THE END OF THE WEEK. SOUTH
OF US 24, HIGHS WILL GENERALLY REACH 50, WITH THOSE IN SOUTHERN
MICHIGAN IN THE 40S. WINTER SNAPS BACK NEXT WEEK AS A DEEP LOW
RACES ACROSS THE UPPER GREAT LAKES. THIS SENDS A COLD FRONT
THROUGH OUR AREA SUNDAY NIGHT RESULTING IN WINDY CONDITIONS AND
PERIOD OF RAIN CHANGING TO LAKE EFFECT SNOW. HIGHS ON MONDAY
WILL BE NEAR 20. PRECEDING THIS, INHERITED HIGH TEMPERATURES
SUNDAY WERE AGAIN THE WARMEST AMONG OTHER MEMBERS, REQUIRING A
REDUCTION INTO THE 50S.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1129 AM EST WED DEC 24 2025
DRY AND PRIMARILY VFR CONDITIONS WILL PREVAIL THIS AFTERNOON
INTO EARLY THIS EVENING IN ADVANCE OF A QUICK MOVING FRONTAL
WAVE MOVING THROUGH TONIGHT. LIGHT RAIN SHOWERS AND A PERIOD OF
IFR TO LOW MVFR CONDITIONS WILL ACCOMPANY THIS WAVE WITH
IMPROVEMENT BACK TO VFR ANTICIPATED TOWARD MIDDAY THURSDAY.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...BROWN
AVIATION...STEINWEDEL
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