469
FXUS63 KIWX 231141
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
641 AM EST FRI JAN 23 2026
KEY MESSAGES
- LAKE EFFECT SNOW SHOWERS ARE EXPECTED FOR WEST-NORTHWEST WIND
FAVORED REGIONS THROUGH EARLY SATURDAY MORNING. ACCUMULATIONS
OF 1 TO 3 INCHES ARE EXPECTED, WITH THE GREATEST TOTALS IN
MICHIGAN. TRAVEL WITH CAUTION AS VISIBILITY WILL BE LIMITED
WITHIN SNOW BANDS.
- A COLD WEATHER ADVISORY IS IN EFFECT THROUGH SATURDAY
MORNING. BREEZY WEST-NORTHWEST WINDS COMBINED WITH
TEMPERATURES IN THE SINGLE DIGITS ABOVE AND BELOW ZERO WILL
LEAD TO DANGEROUS WIND CHILLS OF 15 TO 25 BELOW ZERO AT TIMES.
COLDEST CONDITIONS WILL BE IN THE OVERNIGHT AND EARLY MORNING
PERIODS.
- A WINTER STORM WATCH FOR HEAVY SNOW IS IN EFFECT SATURDAY
NIGHT INTO SUNDAY EVENING FOR AREAS GENERALLY ALONG AND SOUTH
OF US 24, EAST OF HIGHWAY 35. SNOW ACCUMULATIONS OF AROUND 6
INCHES ARE POSSIBLE FOR MOST OF THE WATCH AREA. AREAS EAST OF
I 69 AND SOUTH OF US 30 HAVE THE GREATEST POTENTIAL FOR
ACCUMULATIONS TO EXCEED 6 INCHES.
DISCUSSION
ISSUED AT 639 AM EST FRI JAN 23 2026
THE MAIN CHANGES MADE OVERNIGHT TO THE FORECAST WERE TO ADD GREATER
DETAIL TO THE WINTER STORM WATCH FOR PORTIONS OF THE AREA, AND TO
EXTEND THE SOUTHERNMOST SEGMENT OF THE COLD WEATHER ADVISORY.
GREATER DETAILS ON EACH OF THESE, PLUS A DISCUSSION ON TODAY-
TONIGHT'S LAKE EFFECT ARE BELOW.
1. COLD WEATHER ADVISORY
EXTENDED THE COLD WEATHER ADVISORY INTO SATURDAY MORNING FOR THE
SEGMENT THAT WAS PRIMARILY SOUTH OF US 24/EAST OF I 69 THAT
INITIALLY ENDED AT 1 PM EST TODAY. THE PRIMARY REASON WAS THAT WIND
CHILL VALUES ARE SLIGHTLY LOWER THAN PREVIOUSLY FORECASTED FOR EARLY
THIS MORNING AND AGAIN TONIGHT (PREVIOUSLY 10 TO 15 BELOW ZERO; NOW
REACHING 15 TO 20 BELOW ZERO AT TIMES). INITIALLY FORECASTERS HELD
OFF ON EXTENDING THIS SOUTHERN SEGMENT BECAUSE THE AFTERNOON WIND
CHILLS TODAY WERE BELOW COLD WEATHER ADVISORY CRITERIA (5 TO 10
BELOW I THINK PREVIOUSLY)-AND BECAUSE TONIGHT'S WIND CHILLS LOOKED
TO MARGINALLY MEET THE CRITERIA OF 15 BELOW REQUIRED FOR THE
ADVISORY. HOWEVER, WITH THE ADJUSTMENT TO WINDS/TEMPS THIS FORECAST
ISSUANCE THE WIND CHILLS FOR THE AFTERNOON AND EARLY EVENING WILL
RANGE CLOSER TO 10 TO 15 BELOW ZERO, THEN DROP OVERNIGHT INTO SAT AM
MORE PERSISTENTLY TO AROUND 15 TO 20 BELOW. EXTENDING THE ADVISORY
MADE SENSE-ESPECIALLY GIVEN OUR NEIGHBORING OFFICES HAVE THEIR
ADVISORIES PERSISTING THROUGH TONIGHT/SAT AM AS WELL (PREVIOUSLY HAD
A GAP). HIGH TEMPERATURES TODAY WILL STRUGGLE TO MAKE IT OUT OF THE
SINGLE DIGITS ABOVE ZERO, WITH LOW TEMPS FALLING INTO THE SINGLE
DIGITS BELOW ZERO TONIGHT (SOME AREAS IN MI/FAR NORTHERN IN COULD
REACH 10 BELOW). WEST-NORTHWEST WINDS TODAY OF AROUND 15 MPH WITH
GUSTS UP TO 25 TO 30 MPH WILL MAKE FOR QUITE A MISERABLE DAY-UNLESS
OF COURSE YOU ENJOY THE COLD.
2. WINTER STORM WATCH FROM 7 PM ET SAT(24TH)-7 PM ET INTO SUN(25TH)
TODAY WAS A TOUGH DECISION REGARDING WHETHER OR NOT TO MAKE CHANGES
TO THE INITIAL WATCH AREA OR TO UPGRADE PORTIONS TO A WARNING. IN
THE END, I LEFT THE WATCH IN PLACE FOR NOW WITH NO EXPANSIONS FROM
THE PREVIOUS ISSUANCE. MY CURRENT STORM TOTAL SNOW FORECAST FOR THIS
24 HOUR PERIOD BASED ON THE AVAILABLE DATA HAD THE GREATEST TOTALS
SOUTH AND EAST:
*1 TO 3 INCHES IN SOUTHERN LOWER MI OUTSIDE OF HILLSDALE COUNTY AND
SOUTHERN BERRIEN (3-4").
*3-5 INCHES ALONG/NORTH OF US 24, WITH GREATEST VALUES ALONG US 24
EAST OF HIGHWAY 35.
*BETWEEN 5-6" SOUTH OF US 24, EAST OF HIGHWAY 35. I DO HAVE AROUND
6.5" FOR MUCH OF ALLEN COUNTY, OH AND JAY/BLACKFORD COUNTY, IN--AND
THEN FOR SMALLER PORTIONS OF VAN WERT COUNTY, OH AND ADAMS/GRANT
COUNTY, IN.
I'M MOST CONFIDENT IN SEEING SNOW ACCUMS MEET/EXCEED 6" FOR AREAS
GENERALLY SOUTH OF US 30 AND EAST OF I 69-BUT THERE IS STILL JUST
ENOUGH UNCERTAINTY AMONGST THE MODELS THAT WORST CASE SCENARIO HAVE
THIS END UP AS AN ADVISORY EVENT. IF THE GFS (AND SOME OF THE OTHER
GUIDANCE) IS RIGHT, THE TIMING WILL SHIFT ABOUT 6 HOURS, AND QPF
WILL DROP BY ABOUT 0.03-0.06" IN THE WATCH AREA, AND AS MUCH AS 0.05
TO 0.10" FOR AREAS FURTHER NORTH AND WEST-WHICH WOULD IMPACT SNOW
TOTALS ENOUGH TO KEEP MOST OF THE AREA MORE IN THE ADVISORY REALM.
IF THE NAM OR SIMILAR GUIDANCE IS RIGHT, QPF INCREASES BY ABOUT 0.1-
0.2" ACROSS THE BOARD (ISOLATED UP TO 0.3" INCREASE), WHICH WOULD
INCREASE SNOW TOTALS INTO WARNING CRITERIA (AND ADVISORY NEEDS WOULD
EXPAND NORTHWEST). FOR YOUR AMUSEMENT AND TO DEMONSTRATE THE RANGE
OF POTENTIAL OUTCOMES THAT LEAD TO MY LIMITED CONFIDENCE...THE SNOW
PROBABILITIES FOR THIS TIME PERIOD IN THE WATCH AREA RANGE FROM 1-3"
(LOW END) TO 8-11" (HIGH END). THE HIGHER SOLUTION WOULD ALSO RESULT
IN WIDESPREAD ADVISORY/WARNING CRITERIA WELL BEYOND THE CURRENT
WATCH AREA (WHEREAS LOW END SUGGESTS 0 TO 2" OUTSIDE OF WATCH).
I USED THE PROBABILITIES OF EXCEEDENCE FOR SNOW TOTALS TO GUIDE
MY FINAL DECISION ON THE WATCH:
*PROBABILITIES FOR EXCEEDING 4" ARE 60-80 PERCENT (BEST FURTHER
SOUTH AND EAST). AREAS ALONG US 24 THAT ARE FURTHER NORTH AND WEST
ARE CLOSER TO 45-50 PERCENT (20-45% FOR MI COUNTIES, HIGHEST EAST).
*PROBABILITIES FOR EXCEEDING 6" ARE GENERALLY 30-50% ALONG OR JUST
NORTH OF US 24. AREAS JUST SOUTH OF US 24 ARE IN THE 40 TO 60
PERCENT RANGE-WITH VALUES OF 50-60 PERCENT CONFINED TO THE AREA
ALONG/SOUTH OF US 30, EAST OF I 69.
*PROBABILITIES FOR EXCEEDING 8" ARE AROUND 25-40% IN THE WATCH AREA,
WITH HIGHEST VALUES EAST OF I 69 AND ALONG/SOUTH OF US 30 (GREATEST
IN ALLEN/SOUTHERN VAN WERT IN OH; JAY, BLACKFORD, AND SOUTHERN
ADAMS/GRANT COUNTIES IN IN.
GENERALLY SPEAKING THE SOMEWHAT SUBJECTIVE FORECASTER CONFIDENCE
LEVEL FOR A WARNING NEEDS TO BE 80 PERCENT...AND WITH THESE
PROBABILITIES BELOW THAT I OPTED TO KEEP THE WATCH.
IND/ILN OPTED TO UPGRADE THEIR WATCH TO A WINTER STORM WARNING-WHICH
MAKES SENSE AS CONFIDENCE IS MUCH HIGHER TO THE SOUTH (THEIR
CRITERIA IS ALSO 5" WHEREAS OURS IS 6"). CLE WAS CONSIDERING
UPGRADING FOR PORTIONS OF THEIR AREA BUT DECIDED TO KEEP THE WATCH
AS WELL GIVEN UNCERTAINTIES. I WAS CLOSE TO UPGRADING THE AREAS
ALONG THE IND/ILN/BORDER (WITH BEST CHANCE OF EXCEEDING 6-8"), BUT
THOUGHT IT WOULD BE BEST TO HOLD OFF GIVEN WE ARE STILL 36 HOURS OUT
FROM THE EVENT. IN MY EXPERIENCE, PHASING WAVES LIKE WHAT MAY OCCUR
WITH THIS EVENT HAVE A HIGH BUST RISK. HOPEFULLY GUIDANCE COMES INTO
BETTER ALIGNMENT FOR THE NEXT FORECAST UPDATE-ESPECIALLY AS THE MAIN
WAVE WITH THIS SYSTEM COMES ON SHORE FOR BETTER SAMPLING OUT WEST.
3. LAKE EFFECT SNOW TODAY INTO SATURDAY MORNING
LAST BUT NOT LEAST, EXPECTING AROUND 1-3" OF LAKE EFFECT SNOW TODAY
FOR W-NW FAVORED SNOW BELTS. WINDS WILL GRADUALLY SHIFT NORTHEAST
OVERNIGHT AND EAST-SOUTHEAST BY SATURDAY MORNING, WHICH WILL FORCE
ANY REMAINING BANDS OFFSHORE (PERHAPS A LITTLE MESOLOW OVER LAKE MI
PER THE HI-RES GUIDANCE). HAVE A HIGH POP/LOWER QPF FORECAST BECAUSE
OF THE COLD...THE DGZ IS ESSENTIALLY AT THE GROUND SO THIS WILL
LIMIT THE OPTIMAL DENDRITE FORMATION FOR HIGHER SNOW TOTALS. GUSTY
WINDS NEAR THE LAKESHORE MAY ALSO SERVE TO BREAK APART ANY BETTER
FORMED SNOWFLAKES. WE ARE ALSO WORKING WITH A FAIRLY DRY AIRMASS,
WHICH WILL LIMIT QPF. WE DO GET A BOOST OF FORCING WITH A COUPLE OF
SHORTWAVES MOVING THROUGH THIS AFTERNOON AND EVENING THAT MAY
INCREASE RATES FOR A PERIOD-BUT NOT FEELING CONFIDENT IN TOTALS
GREATER THAN 3" OR SO. IF TRAVELLING NEAR THE LAKESHORE, CONSIDER
ALLOWING FOR EXTRA TIME TO REACH YOUR DESTINATION. EVEN THOUGH SNOW
TOTALS WILL BE LIMITED, THE SMALL FLAKE SIZE AND ANY BLOWING SNOW
THANKS TO GUSTY WINDS TODAY WILL CERTAINLY CAUSE VISIBILITY
RESTRICTIONS. DRIVING IN AND OUT OF LAKE EFFECT SNOW BANDS IS
HAZARDOUS IN ITSELF AS VISIBILITY CAN QUICKLY DETERIORATE. ROADS MAY
ALSO BE SLICK IN PLACES WITH HIGHER ACCUMULATIONS.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 639 AM EST FRI JAN 23 2026
BITTERLY COLD WNW FLOW WILL CONTINUE TO ALLOW LES TO IMPACT MAINLY
KSBN TODAY INTO THIS EVENING WITH HIGHLY VARIABLE VISBYS WITH SNOW
SHOWERS. A FEW FLURRIES AND A TREND TOWARD MVFR CIGS GET INTO KFWA
LATER THIS MORNING AND AFTERNOON. WEST-NORTHWEST WINDS GUSTING UP TO
25 KNOTS TODAY DIMINISH TONIGHT OTHERWISE.
IWX WATCHES/WARNINGS/ADVISORIES
IN...COLD WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ SATURDAY FOR
INZ005>009-012>015-017-018-020-022>027-032>034-103-104-
116-203-204-216.
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
EVENING FOR INZ018-022>027-032>034.
OH...COLD WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR OHZ001-002-
004-005-015-016-024-025.
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY
EVENING FOR OHZ002-004-005-015-016-024-025.
MI...COLD WEATHER ADVISORY UNTIL 10 AM EST SATURDAY FOR MIZ078>081-
177-277.
MARINE...GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LMZ043-046.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST SATURDAY FOR
LMZ043-046.
DISCUSSION...MCD
AVIATION...STEINWEDEL
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