178
FXUS63 KIWX 051748
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1248 PM EST THU FEB 5 2026
KEY MESSAGES
- SCATTERED SNOW SHOWERS ARE EXPECTED THIS AFTERNOON WITH A
LIGHT DUSTING OF ACCUMULATION POSSIBLE.
- A PERIOD OF FREEZING DRIZZLE IS POSSIBLE TONIGHT BUT
CONFIDENCE IN AREA, INTENSITY AND IMPACTS IS VERY LOW.
- AROUND AN INCH OF SNOW IS EXPECTED FRIDAY MORNING, WITH
ADDITIONAL LIGHT LAKE EFFECT FRIDAY NIGHT.
DISCUSSION
ISSUED AT 330 AM EST THU FEB 5 2026
NEXT SHORTWAVE TO IMPACT OUR CWA IS CURRENTLY DIGGING INTO THE
ARROWHEAD OF MINNESOTA ON THE CYCLONICALLY SHEARED SIDE OF A 140+ KT
JET AT 300MB. THIS JET STREAK AND ATTENDANT TROUGH WILL TEND TO GET
SHEARED OUT AS THEY DIVE SOUTHEAST AND INTERACT WITH BROAD SOUTHEAST
CONUS TROUGH. A MODEST SURGE OF 280-285K SYSTEM-RELATIVE ISENTROPIC
ASCENT IS NOTED OVER OUR AREA THIS AFTERNOON WITH THE BEST ASCENT IN
OUR N/NE COUNTIES. STILL, THE LLJ AND ASSOCIATED THETA-E ADVECTION
IS RELATIVELY WEAK CONSIDERING THE DEGREE OF DRY AIR IN PLACE.
EXPECT A BRIEF WINDOW OF SOME LIGHT SNOW SHOWERS 18-00Z BUT THEY
WILL REMAIN SCATTERED AND ANY ACCUMULATION WILL BE A DUSTING AT
BEST. WILL HOLD POP'S IN THE MID CHANCE CATEGORY AND LOWER QPF/SNOW
TO A TENTH OR TWO. STRATUS LEADING TO ANOTHER CHALLENGING TEMP
FORECAST BUT EXPECT OVERCAST SKIES TO RULE THE DAY WITH HIGHS IN THE
LOW/MID 20S. STILL THINK THERE IS SOME POTENTIAL FOR FREEZING
DRIZZLE TONIGHT. A MORE LACKLUSTER MOISTURE PROFILE FROM SHEARING
INITIAL WAVE DOES RAISE SOME DOUBTS, ESPECIALLY EARLY IN THE
EVENING GIVEN LIMITED NEAR-SURFACE OMEGA AND SOME HINTS OF RESIDUAL
DRY AIR. HOWEVER, SEVERAL HI-RES MODELS SHOW MOISTURE ADVECTION
INCREASING THROUGH THE NIGHT AHEAD OF THE NEXT CLIPPER SYSTEM.
BETTER MID/UPPER LEVEL SATURATION DOES OCCUR BY 09Z FRI WITH THE
ARRIVAL OF THIS SHORTWAVE BUT THERE DOES APPEAR TO BE A FEW HOUR
WINDOW WHERE THERE WILL BE SUFFICIENT MOISTURE ADVECTION/WEAK ASCENT
WITHOUT ICE NUCLEATION. WILL THEREFORE MAINTAIN SOME FREEZING
DRIZZLE MENTION, BUT CONFIDENCE IN DURATION, AREA, AND IMPACTS
IS LOW AND NO HEADLINES PLANNED AT THIS TIME.
FRIDAY'S WAVE STILL APPEARS TO START A LITTLE STRONGER AND WILL NOT
HAVE THE SHEARING INFLUENCE OF THE SOUTHEAST CONUS TROUGH. IT
FEATURES STRONGER ISENTROPIC UPGLIDE, BETTER MOISTURE CONVERGENCE
AND A BETTER FGEN SIGNAL. THE ONLY NEGATIVE IS THAT THE WINDOW FOR
GOOD ASCENT IS VERY SHORT, LIKELY ONLY A FEW HOURS ON EITHER SIDE OF
15Z (EARLIER NW/LATER SE). A QUICK INCH OR SO IS LIKELY FOR MOST
AREAS WITH THE BEST CHANCE FOR SLIGHTLY HIGHER AMOUNTS STILL EAST OF
I-69 BUT SYNOPTIC PRECIP ENDS EVERYWHERE BY 18Z AND HIGHS CLIMB INTO
THE MID 30S GIVEN STRONG WAA. THIS WILL LIKELY LIMIT IMPACT ON THE
ROADS, ESPECIALLY GIVEN INCREASING SUN ANGLE IN FEB. SOME LAKE
RESPONSE IS EXPECTED FRI AFTERNOON THROUGH SAT MORNING AS CAA RAMPS
UP BEHIND THE WAVE. FETCH IS GOOD WITH A LARGE NORTHERLY COMPONENT
BUT STREAMLINES SHOW AN ORIGIN OVER THE WESTERN U.P./WISCONSIN
LIMITING GOOD SUPERIOR CONNECTION. INVERSION HEIGHTS ARE ALSO NOT
GREAT (AROUND 5 KFT AT BEST) WITH INCREASING DRY AIR ENTRAINMENT AND
LIMITED THETA-E LAPSE RATES AS THE NIGHT GOES ON. EXPECT SOME SCT
SNOW SHOWERS IN OUR NW ZONES WITH SOME LOCALIZED AMOUNTS OF AN INCH
OR TWO POSSIBLE (MAINLY LA PORTE COUNTY) BUT OVERALL LIMITED
SCOPE/IMPACTS. SAT MORNING WILL ALSO BE COLD AWAY FROM THE LAKE
CLOUDS WITH LOWS NEAR ZERO AND WIND CHILLS NEAR -10F.
A MORE SUBSTANTIAL WARMUP STILL APPEARS POSSIBLE NEXT WEEK. COLD,
DEEP SNOWPACK WILL MODULATE HIGHS QUITE A BIT, ESPECIALLY IF
DEWPOINTS STAY BELOW FREEZING, BUT A RUN AT 40F IS POSSIBLE. THERE
WILL ALSO BE INCREASING PRECIP CHANCES BY THE MIDDLE OF NEXT WEEK.
PRECIP TYPES MAY BE SOMETHING TO WATCH HERE WITH ABUNDANT WAA ALOFT
AND SURFACE TEMPS STUCK AROUND FREEZING BUT DETAILS REMAIN VERY
UNCERTAIN AT THIS TIME RANGE.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1245 PM EST THU FEB 5 2026
AN UPPER VORT MAX INDUCED BY A COMPACT 125 KNOT JET STREAK WILL
DIG ACROSS NORTHERN INDIANA THIS AFTERNOON. SOME WARM ADVECTION
AND WEAK MOISTURE RETURN AHEAD OF THIS FEATURE WILL ALLOW FOR
SOME LIGHT SNOW TO OVERSPREAD NORTHERN INDIANA THROUGH LATE
AFTERNOON. SNOWFALL ACCUMULATIONS ARE EXPECTED TO BE MINOR AND
GENERALLY UNDER A HALF INCH AT KSBN, WITH LESSER AMOUNTS FOR
KFWA AREA WHERE LITTLE TO NO SNOW ACCUMULATION IS EXPECTED.
PASSAGE OF THIS SHORT WAVE LATER THIS AFTERNOON/EARLY EVENING
WILL LEAD TO DRYING OUT OF FAVORED SNOW PRODUCTION LAYER WHICH
RESULTS IN SOME QUESTION AS TO FREEZING DRIZZLE POTENTIAL. SOME
LINGERING SHALLOW WARM ADVECTION LIFT COULD AID IN PATCHY LIGHT
FREEZING DRIZZLE POTENTIAL THIS EVENING/EARLY OVERNIGHT, BUT
CONFIDENCE IN THIS SCENARIO REMAINS QUITE LOW. THE ACTIVE
PATTERN CONTINUES FRIDAY MORNING AS ANOTHER SHEARED WAVE HELPS
DEVELOP SOME LOW LEVEL FRONTAL FORCING FOR A PERIOD OF SNOW
FOCUSED IN THE 10Z-16Z PERIOD. MVFR CIGS TO BEGIN THIS PERIOD
SHOULD DETERIORATE TO LOWER END MVFR OR POSSIBLY IFR LATER
TONIGHT INTO FRIDAY. IN REGARDS TO WINDS, SOUTHWEST WINDS AROUND
10 KNOTS WITH A FEW GUSTS TO 15 TO 20 KNOTS THIS AFTERNOON WILL
VEER WESTERLY BEHIND SFC COLD FRONT FRIDAY AM, BUT A SECONDARY
THROUGH IN THE AFTERNOON WILL BRING SOME HIGHS GUST POTENTIAL OF
25 TO 30 KNOTS TOWARD END OF AND BEYOND THIS FORECAST VALID
PERIOD.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...AGD
AVIATION...MARSILI
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