338
FXUS63 KIWX 050527
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1227 AM EST THU FEB 5 2026
KEY MESSAGES
- LIGHT SNOW THURSDAY AFTERNOON WITH UP TO 0.5' OF ACCUMULATION
POSSIBLE.
- FREEZING DRIZZLE POSSIBLE THURSDAY NIGHT INTO EARLY FRIDAY
AHEAD OF ANOTHER ROUND OF SNOW. SNOW FRIDAY MORNING COULD
ACCUMULATE 1-2", ESPECIALLY EAST OF I-69.
- LAKE EFFECT MAY DEVELOP FRIDAY AFTERNOON THROUGH EARLY SATURDAY
DOWNWIND OF LAKE MICHIGAN.
- A BRIEF COLD SNAP SATURDAY WILL BE FOLLOWED BY A WARM UP INTO
EARLY TO MIDDLE OF NEXT WEEK.
DISCUSSION
ISSUED AT 239 PM EST WED FEB 4 2026
SURFACE HIGH PRESSURE IS KEEPING OUR AREA LOCKED UNDER A LOW LEVEL
STRATUS DECK TODAY WITH PERSISTENT NORTHERLY WINDS. AS CLOUDS
PERSIST TONIGHT, TEMPERATURES ONLY FALL FROM WHERE THEY ARE NOW IN
THE UPPER TEENS AND LOW 20S INTO THE LOW TEENS OVERNIGHT (AS OPPOSED
TO TANKING INTO THE SINGLE DIGITS AND EVEN BELOW ZERO UNDER CLEAR
SKIES LIKE WHAT HAS HAPPENED OVER THE PAST WEEK). WINDS OVERNIGHT
INTO THE DAY ON THURSDAY SHIFT TO BECOME SOUTHWESTERLY, USHERING IN
WAA AHEAD OF OUR NEXT CHANCES FOR PRECIPITATION.
SEVERAL OPPORTUNTIES FOR PRECIPITATION ARISE THURSDAY AFTERNOON
THROUGH FRIDAY. TWO 500MB SHORTWAVES SWEEP THROUGH THE UPPER
MIDWEST AND GREAT LAKES REGIONS DURING THIS TIMEFRAME. THE FIRST
COMES THROUGH THURSDAY AFTERNOON AND TEMPERATURES WILL BE COLD
ENOUGH (LOW TO MID 20S) TO SUPPORT PRECIPITATION FALLING AS
SNOW. THURSDAY NIGHT, SNOW AMOUNTS WILL BE UP TO 0.5" FOR THE
ENTIRE AREA. LIGHT SNOW WILL PERSIST THROUGH THURSDAY NIGHT,
THEN FREEZING DRIZZLE MAY DEVELOP IN BETWEEN THE LULL IN SNOW.
THE BEST POTENTIAL OF FREEZING DRIZZLE APPEARS TO BE LATE
THURSDAY NIGHT THROUGH EARLY FRIDAY MORNING, IN BETWEEN ROUNDS
OF SNOW AND ALONG THE LEADING EDGE OF THE SECOND ROUND. MODELS
ARE PICKING UP A GLAZE TO A FEW HUNDREDTHS OF ICE AT MOST. THE
SECOND ROUND OF SNOW MOVES THROUGH FRIDAY MORNING AND EARLY
AFTERNOON AS A CLIPPER SYSTEM COMES THROUGH WITH THE ASSOCIATED
SECOND 500MB SHORTWAVE. THIS ROUND WILL BE SLIGHTLY MORE POTENT,
WITH SNOW AMOUNTS AROUND 1" EXPECTED EAST OF I- 69. LOCALIZED
AMOUNTS UP TO 2" WILL BE POSSIBLE IN OUR FAR NORTHWEST CWA.
OVERALL, HAVE STAYED CONSISTENT WITH THE PREVIOUS SHIFT IN TERMS
OF SNOWFALL AND QPF. USED A BLEND OF THE PREVIOUS FORECAST WITH
THE WPC GUIDANCE FOR PRECIPITATION AND SLRS. HIGHS ON FRIDAY
WILL BE IN THE MID 30S, WHICH WILL BE THE FIRST DAY ABOVE
FREEZING IN TWO WEEKS! EVEN THOUGH HIGHS WILL ONLY BE ABOVE
FREEZING FOR A FEW HOURS DURING THE DAY, THIS WILL LIMIT THE
SNOWFALL ACCUMULATION EFFICIENCY.
WITH STRONG CAA AND NORTHERLY LOW-LEVEL WINDS BEHIND THE CLIPPER
SYSTEM, LAKE EFFECT SNOW MAY DEVELOP FOR NORTHWEST INDIANA AND
SOUTHWEST LOWER MICHIGAN FRIDAY AFTERNOON INTO EARLY SATURDAY. THE
NAM ESPECIALLY IS STARTING TO PICK UP ON THIS AT THE END OF THE 12Z
RUN. DESPITE THE SHORELINE OF SOUTHERN LAKE MICHIGAN BEING MOSTLY
ICE COVERED, THE OPEN WATERS ARE STILL UNFROZEN. WITH A NORTHERLY
FETCH OVER LAKE MICHIGAN (AND POSSIBLE LAKE SUPERIOR CONNECTION),
THIS IS A FAVORABLE SETUP FOR LAKE EFFECT. IT IS STILL TOO EARLY TO
DETERMINE EXACT AMOUNTS, BUT THE BEST CHANCES FOR LAKE EFFECT WILL
LIKELY BE WEST OF US-31. AN UPPER LEVEL RIDGE BUILDS ACROSS THE
CENTRAL CONUS OVER THE WEEKEND, WHICH WILL ALLOW FOR LAKE EFFECT TO
TAPER OFF SATURDAY AS SUBSIDENCE WORKS IN. TEMPERATURES WILL BE COLD
WITH LOWS IN THE SINGLE DIGITS FRIDAY NIGHT AND SATURDAY'S HIGHS
ONLY IN THE TEENS. ANOTHER CLIPPER SYSTEM IS POSSIBLE SUNDAY,
ALTHOUGH MODEL GUIDANCE VARIES ON TIMING AND TRACK. IT IS
POSSIBLE THIS CLIPPER GOES FURTHER NORTH AND MISSES OUR AREA
COMPLETELY.
INTO NEXT WEEK, A WARM UP AND POSSIBLE THAW IS ON THE WAY! WHILE IT
IS TOO EARLY TO KNOW JUST HOW MILD TEMPERATURES WILL GET, HIGHS WILL
LIKELY BE ABOVE FREEZING FOR SEVERAL DAYS. NBM GUIDANCE HAS HIGHS IN
THE MID TO UPPER 30S (WHICH IS JUST A FEW DEGREES ABOVE NORMAL).
ENSEMBLE GUIDANCE IS MUCH MORE SUPPRESSED THAN IT WAS JUST A
FEW DAYS AGO; ONLY FEW RUNS NOW SHOW TEMPERATURES AS MILD AS THE
UPPER 30S TO LOW 40S. LOW CHANCES FOR HIGHS NEAR 40 WILL BE
ALONG AND SOUTH OF US 24 NEXT TUESDAY AND WEDNESDAY, WITH HIGHER
LIKELIHOOD ACROSS CENTRAL INDIANA. WE LIKELY WON'T MAKE A
MULTI-DAY RUN OF WIDESPREAD HIGHS IN THE 40S.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1224 AM EST THU FEB 5 2026
A COUPLE OF VORT MAXES SLIDE SOUTHEASTWARD AFFECTING THE AREA OVER
THE COURSE OF THIS TAF PERIOD. THE FIRST BEGINS AFFECTING THE AREA
DURING THE MORNING TO MIDDAY HOURS TODAY. LOOKING AT DEW POINT
DEPRESSIONS, THEY AREN'T ALL THAT BAD AT BETWEEN 3 AND 7 DEGREES
WITH THE LOWEST ACTUALLY OCCURING CLOSER TO SBN AT AROUND 18Z
ALTHOUGH IT WON'T BE TOO LONG BEFORE FWA SAW PRECIP AS WELL AND
IT WOULD PROBABLY START AS SNOW. LITTLE IF ANY SNOW ACCUMS ARE
EXPECTED WITH THIS WAVE. BY THE TIME WE GET TO THE EVENING TIME,
DGZ SATURATION DRIES OUT SO PTYPES WOULD PROBABLY BECOME MORE
FREEZING- DRIZZLY WITH AMPLE LIFT IN THE CLOUD LAYER. IT IS A
LITTLE BIT MORE UNCERTAIN HOW LONG THE DRIZZLE WOULD LAST AND IF
IT COULD DRY OUT COMPLETELY TO STOP PRECIPITATING, BUT THE NEXT
WAVE ARRIVES FRIDAY MORNING WITH RENEWED DGZ SATURATION MEANING
PTYPES WOULD TURN TO SNOW BY THAT POINT. FRIDAY SEES THE
GREATER SNOW ACCUMULATION TOTALS.
WE'VE MAINTAINED LOW STRATUS DESPITE MODELS BEGIN INCLINED TO REMOVE
THEM. AVIATION GUIDANCE WANTS TO REMOVE CLOUDS AS EARLY AS 9Z, BUT
GIVEN RECENT HISTORY, WILL HOLD ONTO THESE MVFR CIGS UNTIL THEY MOVE
OUT. THE RAP INDICATES SATURATION FROM THE FIRST WAVE ARRIVES AROUND
16 TO 18Z AT SBN SO HAVE MORE CONFIDENCE IN MVFR CONDITIONS THEN.
WIND-WISE, TRAJECTORIES LOOK TO STAY OUT OF THE SOUTHWEST THROUGH
THE PERIOD. A LLJ BEGINS TO MOVE INTO THE AREA DURING THE DAYTIME,
BUT LOW LEVEL LAPSE RATES ARE RELATIVELY WEAK LIMITING MIXING AND
PROBABLY KEEPING GUSTS BELOW 20 KTS. THEREFORE, SUSTAINED WINDS WILL
BE CAPPED IN THE UPPER SINGLE DIGITS TO MID TEENS OF KTS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...JOHNSON
AVIATION...ROLLER
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