694
FXUS63 KIWX 131104
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
604 AM EST TUE JAN 13 2026
KEY MESSAGES
- LOW CHANCES FOR RAIN OR SPRINKLES TODAY INTO LATE THIS
EVENING, MAINLY ALONG AND NORTH OF THE TOLL ROAD. IT WILL BE
BREEZY WITH HIGHS IN THE 40S. LIGHT RAIN AND/OR SNOW LATE
TONIGHT WILL DROP SOUTHWARD THROUGH WEDNESDAY MORNING, WITH
SNOW MORE LIKELY ALONG AND NORTH OF US 24 BY EARLY WEDNESDAY
MORNING.
- A WINTER STORM WATCH IS IN EFFECT FOR PORTIONS OF THE AREA
WEDNESDAY MORNING INTO THURSDAY AFTERNOON. WIDESPREAD SYSTEM
SNOW PERSISTS WEDNESDAY, GRADUALLY BECOMING MORE OF A LAKE
EFFECT EVENT AS COLD AIR FILTERS IN BEHIND THE SYSTEM. LAKE
EFFECT PERSISTS THROUGH THURSDAY AFTERNOON BEFORE DIMINISHING.
BY THURSDAY AFTERNOON, AREAS ALONG/EAST OF I 69 WILL HAVE
SEEN AROUND 1-2" OF SNOW. NEAR LAKE MICHIGAN, SNOW TOTALS FROM
4 TO 9 INCHES ARE POSSIBLE, HIGHEST WEST OF US 31. BLUSTERY
NORTHWEST WINDS WILL CAUSE BLOWING AND DRIFTING ON EAST-WEST
ROADS, ESPECIALLY NEAR LAKE MICHIGAN.
- ACTIVE WEATHER PERSISTS THROUGH EARLY NEXT WEEK, WITH
POTENTIAL FOR SEVERAL SYSTEM AND LAKE EFFECT SNOW EVENTS.
TEMPERATURES BECOME MUCH COLDER THIS WEEKEND INTO EARLY NEXT
WEEK, WITH LOW TEMPERATURES BOTTOMING OUT IN THE SINGLE DIGITS
STARTING SATURDAY NIGHT.
DISCUSSION
ISSUED AT 603 AM EST TUE JAN 13 2026
AN ACTIVE WEATHER WEEK IS AHEAD, WITH SEVERAL UPPER LEVEL LOWS
DROPPING THROUGH, BRINGING SEVERAL CHANCES FOR SYSTEM AND LAKE
EFFECT SNOW THROUGH EARLY NEXT WEEK. HOWEVER, THE MAIN FOCUS FOR
THIS DISCUSSION IS WEDNESDAY INTO THURSDAY AFTERNOON.
WE HAVE A WINTERS STORM WATCH IN EFFECT FROM 7 AM EST WEDNESDAY
THROUGH 1 PM EST THURSDAY FOR ST. JOSEPH, LAPORTE, STARKE, AND
MARSHALL COUNTIES IN INDIANA; AND BERRIEN COUNTY IN MICHIGAN. THIS
IS PRIMARILY FOR LAKE EFFECT SNOW, HOWEVER THERE WILL BE SOME LIGHT
SYSTEM SNOW TO KICK OF THE EVENT STARTING WED AM. COUNTIES IN THE
WATCH AREA COULD SEE AS MUCH AS 4 TO 9 INCHES OF SNOW (LOCALLY
HIGHER AMOUNTS POSSIBLE DEPENDING ON SNOW BAND MOVEMENT/INTENSITY),
WITH AREAS JUST OUTSIDE OF THE WATCH AREA (ALONG/WEST OF IN SR-15)
MORE IN THE 2-5 INCH RANGE. HAVE HIGH CONFIDENCE IN THE SYSTEM/LAKE
EFFECT SNOW OCCURRING OVERALL IN THIS TIME FRAME-HOWEVER CONFIDENCE
IS A LITTLE LOWER FOR EXACTLY WHERE THE BAND (OR BANDS) SETS UP, HOW
FAR INLAND THEY REACH, AND IF IT'S MORE STATIONARY OR MOVES AROUND
ENOUGH TO DISTRIBUTE THE SNOWFALL THROUGH A BROADER AREA. HAD THE
GREATEST CONFIDENCE FOR WARNING LEVEL SNOW TOTALS AND IMPACTS IN THE
WATCH AREA, AND LESS SO OUTSIDE OF THAT. SUSPECT WE'LL NEED TO ADD
ADVISORIES OUTSIDE THE WATCH AREA-BUT IT WILL DEPEND ON HOW THE
ABOVE MENTIONED FACTORS EVOLVE IN FUTURE MODEL RUNS. FOR EXAMPLE,
HAVE AROUND 5-6" FORECAST FOR PULASKI/FULTON (IN)...BUT LEFT THEM
OUT OF THE WATCH GIVEN UNCERTAINTIES IN HOW THE BANDS ORIENT/EXTEND
INLAND.
AS FOR AN OVERALL TIMELINE, LIGHT RAIN OR SPRINKLES ARE POSSIBLE
THIS AFTERNOON INTO THIS EVENING WITH WARM AIR ADVECTION-MAINLY
ALONG AND NORTH OF THE TOLL ROAD, BUT MOST OF THE GUIDANCE KEEPS IT
NORTH OF OUR AREA. HIGHS WILL WARM INTO THE MID-UPPER 40S FOR SOME
LOCATIONS (FURTHER SOUTH AND WEST). TONIGHT, A BROAD UPPER LEVEL
TROUGH BUILDS IN OVER THE AREA, WITH A SURFACE LOW CROSSING FROM
NORTHERN ONTARIO INTO QUEBEC. THIS WILL BRING AN INITIAL COLD FRONT
THROUGH OUR CWA THIS EVENING (LIGHT RAIN/SPRINKLE POTENTIAL) AND
ANOTHER ONE THAT PASSES THROUGH FROM NORTHWEST TO SOUTHEAST LATE
TONIGHT INTO WEDNESDAY AS THE BASE OF THE UPPER TROUGH/VORT MAX
DEVELOPS OVERHEAD. TEMPERATURES OVERNIGHT WILL DROP INTO THE LOW-MID
30S NORTH OF US 24 BY EARLY WED AM, AND THE MID-UPPER 40S FURTHER
SOUTH. THEY WILL FALL THROUGH THE EARLY MORNING, WITH TEMPS DIVING
INTO THE 20S AND LOW 30S BY AROUND 11 AM-12 PM ET (COLDEST
NORTH/WEST). THERE WILL LIKELY BE A RAIN/SNOW MIX TO START LATE
TONIGHT IN THE NORTHWEST AND INTO LATE WEDNESDAY MORNING FOR AREAS
SOUTH AND EAST. HOWEVER, SNOW CHANGES OVER FAIRLY QUICKLY FOR THE
NORTHWEST AS TEMPERATURES FALL. BY THE END OF THE DAY WEDNESDAY
AREAS ALONG/EAST OF I 69 COULD SEE AROUND 1-2 INCHES (LOWEST
EAST WHERE RAIN AND/OR SNOW MIX WILL LAST THE LONGEST).
THE UPPER LEVEL TROUGH GRADUALLY MOVES EAST THROUGH WEDNESDAY,
EVENTUALLY REACHING LAKE ERIE SOMETIME THURSDAY EVENING AS IT
DEVELOPS INTO A CLOSED LOW. THIS LOW CONTINUES EASTWARD THROUGH
THURSDAY, WITH A SHARP RIDGE BUILDING IN BEHIND IT (INTO OUR CWA).
AS THIS OCCURS, WE'LL SEE A TRANSITION WED AFTERNOON TO MORE OF A
LAKE EFFECT FOCUS THAT INTENSIFIES WEDNESDAY NIGHT INTO THURSDAY
MORNING ESPECIALLY (DISSIPATING/WEAKENING LATE THURSDAY AM/EARLY
THURSDAY AFTERNOON). DELTA T'S END UP AROUND 18 DEGREES AS 850MB
TEMPS DROP TO AROUND -16 TO -17C WITH 0-1KM DELTA THETA-E VALUES
BETWEEN -3 AND -6 K/KM. MOST OF THE GUIDANCE DEPICTS STRONG NORTH-
NORTHWEST FLOW (SOME MORE NORTH THAN OTHERS) THROUGH LATE THU AM
BEFORE IT SHIFTS WEST-SOUTHWEST THURSDAY AFTERNOON WITH THE INCOMING
RIDGE/SURFACE HIGH PRESSURE. WITH THE FLOW BEING MORE UNIDIRECTIONAL
THROUGH THE ATMOSPHERE, EXPECT MORE OF A SINGLE DOMINANT BAND FOCUS
(MAYBE 2 IN SOME CASES...DEPENDING ON THE MODEL RUN)...WITH A DECENT
INLAND EXTENT GIVEN THE TROUGH AXIS IS ALSO MOVING THROUGH FOR THE
FIRST PORTION OF THE EVENT. THERE ARE HINTS AT A LAKE SUPERIOR
CONNECTION (PARTICULARLY FOR THE MORE N-NNW ORIENTED BAND
SOLUTIONS), AND MOST OF THE LIFT IS WITHIN A VERY SATURATED DGZ. I
SUSPECT WE'LL SEE DECENT SNOW RATIOS WITH THIS (20:1 PROBABLY A GOOD
STARTING POINT BUT WOULDN'T BE SURPRISED TO SEE HIGHER
VALUES)-THOUGH THERE COULD BE SOME FRACTURING TO DENDRITES WITH
THE STRONG SURFACE WINDS (GUSTS OF 30-40 MPH POSSIBLE WED INTO
LATE WED NIGHT/THU AM, ESPECIALLY NEAR LAKE MI). INVERSION
HEIGHTS LINGER AROUND 8KFT THROUGH MOST OF THE EVENT, DWINDLING
DOWN TO AROUND 3-4KFT ONCE THE INCOMING RIDGE BUILDS IN FOR THE
AFTERNOON THURSDAY. AT THIS TIME, HAVE THE PEAK EVENT INTENSITY
WEDNESDAY NIGHT INTO THU (WITH THE MOST SNOWFALL OCCURRING IN
THAT TIME). SOME OF THE HIGH RES MODELS SUGGEST ONCE THE PEAK
WINDS INLAND DIE DOWN AND THE TROUGH AXIS SHIFTS FURTHER SOUTH
AND EAST-WE COULD SEE ENHANCED CONVERGENCE FROM A LAND BREEZE-
WHICH COULD SHIFT THE BAND AS FAR WEST AS PORTER COUNTY,
IN...BUT IT'S TOO EARLY TO DETERMINE AT THIS POINT.
WITH THE DROPPING TEMPERATURES WEDNESDAY AND GUSTY N-NW WINDS, WE'LL
SEE WIND CHILLS IN THE SINGLE DIGITS AND TEENS ABOVE ZERO. IT'S
POSSIBLE WE SEE WIND CHILLS BELOW ZERO WEDNESDAY NIGHT INTO THURSDAY
MORNING AS TEMPERATURES DROP INTO THE TEENS.
ANOTHER UPPER LOW OR TROUGH MOVES INTO THE AREA FRIDAY INTO THE
WEEKEND, WHICH WILL BRING US ADDITIONAL SNOW POTENTIAL AND COLDER
TEMPERATURES.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1235 AM EST TUE JAN 13 2026
WAA ALOFT INCREASES LATER THIS MORNING AHEAD OF THE NEXT TROUGH.
SOME BRIEF/MARGINAL LLWS IS POSSIBLE AT KSBN BEFORE MIXING OUT
BUT SUSPECT KFWA WILL MIX OUT BEFORE THE STRONGEST PORTION OF
THE LLJ MOVES OVERHEAD. VERY DRY LOW LEVELS WILL MAINTAIN VFR
CONDITIONS THROUGH MOST OF THE DAY. HOWEVER, THE INITIAL COLD
FRONT PASSES TUE EVENING AND WILL BRING STRATUS BACK TO THE
AREA. STRATUS WILL INITIALLY HOLD MVFR BUT SOME IFR CEILINGS ARE
POSSIBLE BY EARLY WED MORNING, ESPECIALLY AT KSBN. SOME LIGHT
RAIN OR SNOW IS ALSO POSSIBLE AFTER 06Z TUE NIGHT BUT WILL
LIKELY HOLD OFF UNTIL AFTER 12Z WED MORNING.
IWX WATCHES/WARNINGS/ADVISORIES
IN...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
AFTERNOON FOR INZ012-014-103-104-203-204.
OH...NONE.
MI...WINTER STORM WATCH FROM WEDNESDAY MORNING THROUGH THURSDAY
AFTERNOON FOR MIZ177-277.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST WEDNESDAY FOR LMZ043-046.
GALE WARNING FROM 4 AM WEDNESDAY TO 4 AM EST THURSDAY FOR
LMZ043-046.
DISCUSSION...MCD
AVIATION...AGD
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