939
FXUS63 KIWX 122330
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
630 PM EST MON JAN 12 2026
KEY MESSAGES
- BREEZY WITH SLIGHT CHANCES (20-30%) FOR LIGHT RAIN TUESDAY
AFTERNOON AND EVENING. HIGHS WILL BE IN THE MID TO UPPER 40S.
RAIN MAY MIX WITH SNOW LATE TUESDAY NIGHT NORTH OF US 24 AS
TEMPERATURES FALL INTO THE MID 30S.
- LAKE EFFECT SNOW WILL DEVELOP WEDNESDAY AND PERSIST INTO
THURSDAY FOR NORTH-NORTHWEST WIND FAVORED SNOWBELTS. IT'S
POSSIBLE THAT LOCATIONS IN SOUTHERN BERRIEN, LA PORTE, AND
STARKE COUNTIES SEE GREATER THAN 6 INCHES OF ACCUMULATION BY
THURSDAY PM.
- THE WEDNESDAY PM AND THURSDAY AM COMMUTES ARE MOST LIKELY TO
BE IMPACTED BY THE LAKE EFFECT SNOW. NORTHWEST WINDS GUSTING
UP TO 35 MPH MAY ALSO CREATE BLOWING AND DRIFTING SNOW.
- COLDER WITH ANOTHER CHANCE FOR ACCUMULATING SNOW AREA-WIDE FRIDAY
AND INTO THE WEEKEND.
DISCUSSION
ISSUED AT 312 PM EST MON JAN 12 2026
HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI RIVER VALLEY IS
PROVIDING DRY CONDITIONS, SEASONABLE TEMPERATURES, AND EVEN SOME
SUNSHINE TODAY ACROSS OUR FORECAST AREA! ENJOY IT WHILE IT LASTS
BECAUSE AN ACTIVE WEATHER PATTERN IS AHEAD THIS WEEK WITH CHANCES
FOR RAIN AND ALSO SEVERAL OPPORTUNTIES FOR ACCUMULATING SNOW.
A DEEPENING LOW PRESSURE SYSTEM WILL TRAVERSE THROUGH THE UPPER
GREAT LAKES REGION MIDWEEK. BY TUESDAY AFTERNOON, WAA WILL BOOST
TEMPERATURES INTO THE MID 40S. WITHIN THE WARM SECTOR OF THIS
SYSTEM, ANY PRECIPITATION THAT FALLS TUESDAY AFTERNOON WILL BE RAIN.
AS WE WILL BE ON THE PERIPHERY OF THIS SYSTEM TRACKING NORTH OF THE
GREAT LAKES, RAINFALL IS EXPECTED TO BE LIGHT. TUESDAY NIGHT, A COLD
FRONT SWEEPING THROUGH WILL DROP TEMPERATURES INTO THE UPPER 30S.
WEDNEDAY'S HIGH TEMPERATURE WILL BE REACHED BEFORE DAYBREAK AS A
SECONDARY STRONGER COLD FRONT MOVES THROUGH; TEMPERATURES WILL FALL
THROUGHOUT WEDNESDAY IN THE WAKE OF THE FRONT.
CONFIDENCE IS INCREASING FOR AN IMPACTFUL LAKE EFFECT SNOW EVENT TO
DEVELOP FOR NORTHWEST INDIANA AND POTENTIALLY FAR SOUTHWEST LOWER
MICHIGAN DURING THE DAY WEDNESDAY THROUGH AT LEAST THURSDAY MORNING.
IN THE WAKE OF THE COLD FRONT WEDNESDAY MORNING, TEMPERATURES WILL
FALL TO AT OR JUST BELOW FREEZING. CAA AND STRONG LOW LEVEL
CONVERGENT NORTH/NORTHWESTERLY WINDS WILL ALLOW FOR A SINGLE
DOMINANT LAKE EFFECT SNOW BAND TO DEVELOP DOWNWIND OF LAKE MICHIGAN
AROUND DAYBREAK WEDNESDAY. WINDS MAY INITIALLY START OUT NORTHWEST
BEFORE BECOMING NORTH-NORTHWEST OR POSSIBLY DUE NORTH. WITH THIS IN
MIND, THE LAKE EFFECT SNOW BAND WILL LIKELY EXTEND PRETTY FAR INLAND
DUE TO THE ELONGATED FETCH OVER LAKE MICHIGAN. WOULDN'T BE
SURPRISED EITHER IF A LAKE SUPERIOR TO LAKE MICHIGAN CONNECTION
DEVELOPS. DELTA T'S WILL BE AS HIGH AS 17-18C WITH COLD AIR
MOVING OVER THE STILL RELATIVELY MILD AND UNFROZEN LAKE MICHIGAN
(WATER TEMPS BETWEEN 1-3C). IN ADDITION, PARAMETERS APPEAR
FAVORABLE FOR PERIODS OF MODERATE TO HEAVY LAKE EFFECT SNOW
WITHIN THE SINGLE BAND. FORECAST SOUNDINGS AT BENTON HARBOR AND
MICHIGAN CITY DEPICT INCREASING LIFT AND SATURATION WITHIN THE
DGZ, ESPECIALLY WEDNESDAY AFTERNOON AND EVENING. INVERSION
HEIGHTS RISE DURING THE DAY WEDNESDAY TO AROUND 8000 FT. A
POTENT UPPER LEVEL TROUGH PIVOTING THROUGH WEDNESDAY NIGHT WILL
HELP TO INCREASE INSTABILITY AND LARGE- SCALE ASCENT, AND MAY
ALSO HELP TO INTENSIFY SNOW RATES. AT TIMES, SNOWFALL RATES
COULD BE OVER 1" PER HOUR. THIS KIND OF SETUP WITH AN ELONGATED
NORTHERLY FETCH AND POSSIBLE LAKE SUPERIOR CONNECTION FAVORS THE
BULLSEYE OF LAKE EFFECT SNOW AMOUNTS TO BE IN NORTHWEST
INDIANA. OVERALL, SNOW AMOUNTS OF AT LEAST 6" APPEAR LIKELY
FOR SOUTHERN BERRIEN, LA PORTE, AND STARKE COUNTIES IN
NORTHWEST INDIANA. PORTIONS OF SURROUNDING COUNTIES TO THE SOUTH
AND EAST ARE IN THE 4-6" RANGE. I DID CONSIDER ISSUING A WINTER
STORM WATCH WITH THIS FORECAST PACKAGE; LA PORTE COUNTY WILL
DEFINITELY NEED ONE, IT IS JUST A QUESTION OF WHICH SURROUNDING
COUNTIES NEED ONE TOO. DECIDED TO HOLD OFF ON THIS SHIFT DUE TO
UNCERTAINTY ON EXACT BAND PLACEMENT AND HOW FAR THE INLAND
EXTENT MAY BE. IT IS ALSO GOING TO BE WINDY ON THE BACKSIDE OF
THE DEEPENING LOW PRESSURE SYSTEM, WITH NORTHWEST WINDS GUSTING
AS HIGH AS 30 TO 35 MPH ON WEDNESDAY. THIS WILL NOT ONLY FURTHER
REDUCE VISIBILITIES WITHIN ANY STRONG LAKE EFFECT BANDS BUT
ALSO WILL ALLOW FOR BLOWING AND DRIFTING SNOW. THE WEDNESDAY
EVENING AND THURSDAY MORNING COMMUTES WILL LIKELY BE IMPACTED.
DEPENDING ON HOW LONG IT TAKES FOR LAKE EFFECT SNOW TO TAPER
OFF, THE THURSDAY EVENING COMMUTE MAY ALSO BE SLICK AND SLOW-
GOING.
COLDER AIR FOLLOWS FOR THE END OF THE WEEK INTO THE WEEKEND WITH YET
ANOTHER SYSTEM ON THE HORIZON. IN QUICK SUCCESSION WITH THE MIDWEEK
SYSTEM, YET ANOTHER AREA OF LOW PRESSURE TRACKS THROUGH THE GREAT
LAKES REGION. WITH COLDER AIR IN PLACE, A COMBO OF ACCUMULATING
SYSTEM AND LAKE EFFECT SNOW IS POSSIBLE AREA-WIDE ON FRIDAY AND
SATURDAY. IT WILL BE WINDY AGAIN, WHICH WILL DROP WIND CHILLS BELOW
ZERO AT TIMES (ESPECIALLY AT NIGHT). COLDER AIR CONTINUES INTO EARLY
NEXT WEEK WITH HIGHS IN THE 20S AND LOWS IN THE SINGLE DIGITS.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 629 PM EST MON JAN 12 2026
DRY WEATHER CONTINUES ON THE HEELS OF SURFACE HIGH PRESSURE WITHIN
AN AREA OF SLIGHT MID LEVEL HEIGHT RISES OVERNIGHT INTO EARLY
TUESDAY. THE ECMWF INDICATES SUBSTANTIAL HEIGHT FALLS FOR DURING THE
DAY TUESDAY AS A SHORTWAVE TRAVERSES EASTWARD JUST NORTH OF THE AREA
AND ALSO HAS SOME PRECIP WITH IN AN AREA OF 850 MB MOIST ADVECTION.
HOWEVER, THERE'S SOME UNCERTAINTY WITH THIS AN IT APPEARS THE ECMWF
IS ALONE WITH THIS SOLUTION (ALTHOUGH THE AIGFS IS WETTER THAN THE
GFS AT THAT TIME). RAP TIME SECTIONS INDICATE MUCH OF THE ATMOSPHERE
BELOW 700 MB WILL BE DRY SO WILL LEAN VFR WITH THESE TAFS.
WINDS CONTINUE OUT OF THE SSW DURING THIS PERIOD AND HAVE THEIR
GREATEST CHANCE TO ACHIEVE 25 TO 30 KT GUSTS MIDDAY INTO THE
AFTERNOON GIVEN DEEPENING LAPSE RATES. WILL ALSO BE INCLUDING SOME
LLWS IN THESE TAFS WITH THE LOW LEVEL JET AROUND.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 7 PM EST TUESDAY FOR LMZ043-
046.
GALE WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY NIGHT
FOR LMZ043-046.
DISCUSSION...JOHNSON
AVIATION...ROLLER
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