209  
FXUS63 KIWX 181634  
AFDIWX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE NORTHERN INDIANA  
1134 AM EST THU DEC 18 2025  
   
KEY MESSAGES
 
 
- BRIEFLY WARMER TODAY WITH SHOWERS BECOMING MORE NUMEROUS THIS  
AFTERNOON INTO EARLY EVENING.  
 
- WINDY CONDITIONS ARE EXPECTED THIS AFTERNOON INTO THIS  
EVENING WITH NUMEROUS GUSTS OF 35 TO 40 MPH. THE POTENTIAL  
EXISTS FOR GUSTS OF 45 TO 50 MPH, BUT CONFIDENCE IS LOW AT  
THIS TIME.  
 
- A STRONG COLD FRONT WILL BRING A RAPID DROP IN TEMPERATURES  
TONIGHT. WET ROADWAYS COULD FREEZE AS TEMPERATURES FALL  
THROUGH THE 20S, RESULTING IN THE POTENTIAL FOR SOME TRAVEL  
ISSUES OVERNIGHT INTO FRIDAY MORNING. HIGHS FRIDAY WILL BE IN  
THE 20S.  
 
- THE BULK OF THE PERIOD FROM SATURDAY THROUGH CHRISTMAS EVE  
WILL FEATURE ABOVE NORMAL TEMPERATURES AND LIMITED CHANCES FOR  
PRECIPITATION.  
 

 
   
DISCUSSION
 
 
ISSUED AT 421 AM EST THU DEC 18 2025  
 
MULTIPLE CHALLENGES OVER THE NEXT 24 TO 36 HOURS AS A SERIES OF  
FRONTS ASSOCIATED WITH DEEP LOW PRESSURE PASSING WELL NORTH OF  
THE AREA BRING A ROLLER COASTER OF TEMPERATURES, RAIN CHANGING  
TO SNOW AND GUSTY WINDS.  
 
THIS MORNING...  
TEMPERATURES ARE ON THE RISE AS STRONG WAA IS UNDERWAY,  
COURTESY OF 40 TO 50 KT LLJ THAT WILL ONLY INCREASE FURTHER  
THROUGH THE DAY. A WARM FRONT WILL SURGE NORTH INTO THE AREA  
THIS MORNING AND SHOULD MAKE IT TO AT LEAST THE US-30 CORRIDOR  
THIS AFTERNOON. INCREASING ISENTROPIC LIFT AHEAD OF THE FRONT  
SHOULD AID IN THE DEVELOPMENT OF SCATTERED TO NUMEROUS SHOWERS  
OVER THE NEXT SEVERAL HOURS TO OUR WEST AND SOUTH, MOVING IN  
TOWARDS MORNING. WITH LOW LEVEL MOISTURE STARTING OUT LIMITED,  
THE SHOWERS WON'T PRODUCE A LOT OF QPF (< 0.10"). BY NOON  
TEMPERATURES ACROSS THE AREA WILL BE WELL INTO THE 40S WITH  
SOUTHERN AREAS LIKELY FLIRTING WITH 50 DEGREE.  
 
THIS AFTERNOON INTO EARLY EVENING...  
AS THE WARM FRONT ENTERS SOUTHERN AREAS AND THE FIRST OF 2  
STRONG COLD FRONTS APPROACH FROM THE WEST, A SIGNIFICANT UPTICK  
ON PRECIP COVERAGE AND INTENSITY WILL OCCUR FOR A 2 TO 4 HOUR  
PERIOD ALONG AND BEHIND THE FRONT WITH CAMS CONSISTENTLY  
INDICATING A FINE LINE OF SOMEWHAT STRONGER CONVECTIVE ELEMENTS  
THAT COULD PRODUCE BRIEF HEAVY RAIN. HIGHEST POPS SHOULD OCCUR  
IN THE 22Z THU TO 02Z FRI PERIOD. A NOTICEABLE INCREASE IN WINDS  
AND WIND GUSTS WILL OCCUR THIS AFTERNOON WITH MEDIUM TO HIGH  
CONFIDENCE IN FREQUENT GUSTS OF 35 TO 40 MPH. HANDFUL OF CAMS  
CONTINUE TO POINT TOWARDS THE POTENTIAL OF 45 TO POSSIBLY EVEN  
50 MPH WIND GUSTS DESPITE A STRONG LOW LEVEL INVERSION (FURTHER  
STRENGTHENED BY THE COLD GROUND STILL ATTEMPTING TO WARM). WHILE  
THE THREAT CANNOT BE FULLY DISMISSED, ESPECIALLY ALONG THE WARM  
FRONT/COLD FRONT INTERFACE, CONSENSUS WAS TO LIMIT GUSTS TO THE  
ABOVE RANGE AND MONITOR UPSTREAM TRENDS. WILL MESSAGE CONCERNS  
IN SOCIAL MEDIA PRODUCTS AND HWO. TEMPERATURES WILL BEGIN TO  
FALL BEHIND THE FIRST FRONT BUT NOT DROP BELOW FREEZING TILL  
AFTER 03Z. A TRANSITION TO SNOW WILL OCCUR DURING THE EVENING  
HOURS AS THE COLDER AIR BEGINS TO ARRIVE WITH MAYBE A DUSTING IN  
SOME AREAS.  
 
MID EVENING INTO FRIDAY...  
SECOND, MUCH STRONGER COLD FRONT ARRIVES A FEW HOURS BEHIND THE  
FIRST FRONT WITH TEMPERATURES FALLING 15 TO 20 DEGREES FROM MID  
EVENING THROUGH THE OVERNIGHT HOURS. THIS RAPID DROP WILL CAUSE  
ANY LINGERING MOISTURE ON ROADS OR LIGHT PRECIP FALLING TO  
FREEZE, WHICH MAY BRING SOME SLIPPERY CONDITIONS. GUSTY WINDS  
WILL STILL BE UNDERWAY, WHICH MAY HELP IN "DRYING" OF SURFACES  
TO LIMIT THE ICING POTENTIAL. LAKE EFFECT SNOWSHOWERS WILL  
INCREASE IN COVERAGE, BUT GREATEST LAKE RESPONSE LOOKS TO REMAIN  
NORTH OF THE AREA. LOCATIONS IN SW LOWER MI MAY SEE SOME  
ACCUMULATIONS UP TO AN INCH BEFORE THE FLOW WEAKENS AND COLDEST  
AIR BEGINS TO SHIFT AWAY. THE COLD TEMPERATURES AND BREEZY  
CONDITIONS WILL BRING A COLD START TO THE FRI AM COMMUTE WITH  
WIND CHILLS EITHER SIDE OF 0 DEGREES.  
 
REMAINDER OF THE FORECAST PERIOD...  
 
FORECAST FOR FRI NGT THROUGH CHRISTMAS EVE LEFT RELATIVELY  
UNTOUCHED GIVEN THE SHORT TERM CONCERNS. ONE MORE LONGWAVE  
TROUGH WILL MOVE THROUGH THE NORTHERN STREAM. TEMPERATURES WILL  
WARM INTO THE 40S AHEAD OF THE SYSTEM ON SAT, BUT A BRIEF SURGE  
OF COLD AIR FOLLOWS IN ITS WAKE TO DROP HIGHS INTO THE UPR 20S  
TO LOWER 30S SUNDAY.  
 
FROM MONDAY ON, A STRONG UPPER LEVEL RIDGE WILL SET UP ALONG THE  
GULF STATES WITH A MORE ZONAL FLOW SETTING UP WHICH KEEPS ANY  
NORTHERN STREAM WAVES WELL NORTH OF THE AREA. AS HAS BEEN  
ADVERTISED FOR A WHILE, THIS WILL BRING A SHIFT TO ABOVE NORMAL  
TEMPERATURES FOR THE AREA WHICH LOOKS TO LAST MOST LIKELY INTO  
CHRISTMAS DAY.  
 

 
   
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
 
 
ISSUED AT 1134 AM EST THU DEC 18 2025  
 
STRONGLY FORCED COLD FRONT TO MOVE THROUGH KSBN AROUND 23/00Z  
AND KFWA 00/01Z WITH STRONG SOUTHERLY WINDS VEERING WESTERLY IN  
ITS WAKE. A PERIOD OF IFR CONDITIONS AND INCREASING RAIN  
COVERAGE WILL ALSO ACCOMPANY THIS FRONTAL ZONE AS DEEPER  
MOISTURE STREAMS IN. POST-FRONTAL CAA THEN WRAPS IN THIS EVENING  
INTO THE EARLY OVERNIGHT WITH SNOW SHOWERS AND FLURRIES POSSIBLE  
INTO FRIDAY MORNING, BEST CHANCES AT KSBN GIVEN SOME LAKE  
ENHANCEMENT.  
 

 
   
IWX WATCHES/WARNINGS/ADVISORIES
 
 
IN...NONE.  
OH...NONE.  
MI...NONE.  
MARINE...GALE WARNING UNTIL 7 AM EST FRIDAY FOR LMZ043-046.  
 

 
 

 
 
DISCUSSION...FISHER  
AVIATION...STEINWEDEL  
 
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