348
FXUS63 KIWX 152357
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
757 PM EDT THU OCT 15 2026
KEY MESSAGES
- AN AREA OF RAIN SHOWERS AND A FEW EMBEDDED THUNDERSTORMS WILL
OVERSPREAD THE AREA INTO THE EVENING. SCATTERED STRONGER
SHOWERS AND STORMS ARE EXPECTED MID TO LATE EVENING IN ADVANCE
OF A COLD FRONT SOUTH OF US-24.
- THERE IS A MARGINAL RISK OF SEVERE STORMS THROUGH MIDNIGHT ET
MAINLY SOUTH OF US ROUTE 24. THE MAIN THREAT WOULD BE ISOLATED
DAMAGING WIND GUSTS, BUT CONFIDENCE IN SEVERE WEATHER IS LOW.
- TURNING MUCH COOLER AND WINDY FOR FRIDAY WITH SOME LAKE EFFECT
RAIN SHOWERS EXPECTED. THE STRONGEST WIND GUSTS ARE EXPECTED
DOWNWIND OF LAKE MICHIGAN ACROSS BERRIEN AND LA PORTE COUNTIES
WHERE GUSTS TO 45 MPH ARE LIKELY FRIDAY AFTERNOON AND
EVENING.
- THERE ARE CHANCES OF FROST BOTH FRIDAY NIGHT AND SATURDAY NIGHT.
- AFTER BELOW NORMAL TEMPERATURES THIS WEEKEND, TEMPERATURES
WILL WARM BACK ABOVE NORMAL EARLY NEXT WEEK.
DISCUSSION
ISSUED AT 305 PM EDT THU OCT 15 2026
LOW LEVEL WARM/MOIST ADVECTION IS INCREASING THIS AFTERNOON AS A
MID/UPPER RIDGE AXIS SHIFTS ACROSS THE EASTERN GREAT LAKES. LOW
LEVEL FLOW WILL CONTINUE TO STRENGTHEN OVER THE NEXT SEVERAL HOURS
WITH SOME POCKETS OF BETTER LOW LEVEL MOISTURE CONVERGENCE
ASSOCIATED WITH SPEED CONVERGENCE OVERSPREADS THE AREA. SURFACE
LOW PRESSURE ACROSS NE MISSOURI WILL DEEPEN SOME AS A PAIR OF
UPPER LEVEL SHORT WAVES ADVANCE EAST FROM CENTRAL CONUS. THE
FIRST OF THESE WAVES IS ACROSS THE CENTRAL PLAINS THIS AFTERNOON
AND WILL RAPIDLY GET INGESTED NORTHEAST INTO STRONGER WEST-
SOUTHWEST FLOW DOWNSTREAM OF A MORE POTENT/DYNAMIC UPPER LEVEL
TROUGH CURRENTLY DIGGING ACROSS THE DAKOTAS.
THIS EVOLUTION STILL LOOKS INLINE TO SUPPORT A RAPIDLY
NORTHWARD LIFTING WARM FRONT THROUGH THIS EVENING WITH A SHARP
INCREASE IN LOW LEVEL MOISTURE AND NORTHWARD SHIFT OF POOL OF
BETTER INSTABILITY FROM SOUTHEAST MO INTO SOUTHERN IN/WESTERN
KY. IT STILL APPEARS AS THOUGH LOCATIONS IN LOCAL AREA SOUTH OF
US ROUTE 24 WILL HAVE A BRIEF WINDOW OF WEAK MLCAPES (100-300
J/KG) IN THE 01Z-05Z TIMEFRAME TONIGHT. SOME WEAK PREFRONTAL
TROUGH FORCING MAY CONTRIBUTE TO MORE SCATTERED CONVECTION AFTER
INITIAL BANDS OF RAIN SHOWERS LATER THIS AFTERNOON/EARLY
EVENING, WITH AN ENVIRONMENT POTENTIALLY WITH SOME NEAR SFC
BASED INSTABILITY TO WORK WITH. WHILE INSTABILITY MAGNITUDES
WILL REMAIN QUITE WEAK, ROBUST LOW LEVEL AND DEEP LAYER SHEAR
PROFILES WILL BUILD IN FROM THE SOUTHWEST, SO WILL STILL HAVE TO
BE WATCHING FOR SOME ISOLATED STRONG-SEVERE POTENTIAL MID-LATE
EVENING AND POSSIBLY INTO EARLY OVERNIGHT FOR AREAS SOUTH OF
US-24. THE MORE FAVORABLE COMBINATION OF CAPE/SHEAR STILL LOOKS
TO BE DISPLACED SOUTH FROM SOUTHERN IL TO CENTRAL IN WHERE SOME
ISOLATED TORNADO POTENTIAL CANNOT BE RULED OUT GIVEN LOW LEVEL
SHEAR PROFILES. CONFIDENCE IN SEVERE WEATHER POTENTIAL AS FAR
NORTH AS LOCAL AREA REMAINS ON THE LOW SIDE, BUT WILL CONTINUE
TO MONITOR FAR SOUTHERN LOCATIONS LATER THIS EVENING/EARLY
OVERNIGHT. A GOOD DEAL OF CLOUD COVER/LIMITED INSTABILITY AND
STRONGER FORCING DISPLACED WEST AND NORTHWEST OF LOCAL AREA MAY
BE LIMITING FACTORS FOR ISOLATED SEVERE THREAT.
SFC LOW PRESSURE WILL CONTINUE TO DEEPEN FRIDAY MORNING ACROSS
FAR SE ONTARIO/QUEBEC AS THE MORE POTENT NORTHERN PLAINS TROUGH
APPROACHES THE WESTERN GREAT LAKES. LOW LEVEL HEIGHT GRADIENT,
WHILE STRONG ON FRIDAY, DOES NOT LOOK AS STRONG AS SEVERAL
FORECAST CYCLES AGO AS A SECONDARY WEST-EAST LOW LEVEL TROUGH
AXIS WILL BE DROPPING INTO THE REGION FRIDAY AFTERNOON. WIND
GUSTS OF 25 TO 35 MPH WILL LOOK REASONABLE FOR MOST OF THE AREA
WITH AN EXCEPTION OF POTENTIAL 40+ MPH GUSTS CLOSER TO LAKE
MICHIGAN SHORELINE. A WIND ADVISORY HAS BEEN ISSUED FOR BERRIEN
MI AND LAPORTE IN COUNTIES FOR FRIDAY 18Z TO SATURDAY 03Z. THE
POTENTIAL STRONGEST WINDS LOOK TO BE IN THE 18Z-00Z PERIOD
FOLLOWING SECONDARY TROUGH PASSAGE, WITH WARM LAKE WATERS
HELPING POST-FRONTAL MIXING. AFTER 00Z CONFIDENCE IN STRONGER
WIND GUSTS BEGINS TO DIMINISH SOMEWHAT AS SOME THERMAL
MODIFICATION OF MASS FIELDS COULD LEAD TO WEAK LAKE AGGREGATE
TROUGH AND A SLACKENING OF THE GRADIENT. THIS PROCESS SHOULD
PROLONG THE POTENTIAL OF LAKE EFFECT RAIN SHOWERS INTO FRIDAY
NIGHT ACROSS NW IN AND PERHAPS FAR SW LOWER MI.
THE STRONG NEGATIVE UPPER HEIGHT ANOMALY WILL BE PROGRESSIVE THROUGH
THE REGION WITH EXPANSIVE LONGWAVE UPPER RIDGE SPREADING ACROSS
CENTRAL CONUS SATURDAY. A FEW NIGHTS OF FROST POTENTIAL STILL LOOK
ON TRACK. ON FRIDAY NIGHT THERE COULD BE AN AREA ACROSS CENTRAL
PORTIONS OF THE FORECAST AREA THAT MAY BE SITUATED BETWEEN
LINGERING LAKE EFFECT CLOUDS TO THE WEST, AND LINGERING BETTER
MIXING TO THE EAST TO ALLOW FOR SOME PATCHY FROST. SATURDAY
NIGHT/SUNDAY AM WILL ALSO FEATURE PATCHY FROST POTENTIAL, WITH
BEST CHANCES ACROSS APPROX SE 2/3RD OF THE AREA AS WEAK RETURN
SOUTHWEST FLOW DEVELOPS ACROSS WESTERN/SOUTHERN GREAT LAKES.
MUCH OF NEXT WORK WEEK LOOKS MUCH QUIETER WEATHER-WISE AS
PRIMARY STORM TRACK REMAINS ACROSS SOUTHERN CANADA WHILE
LONGWAVE RIDGING DOMINATES CENTRAL PART OF THE COUNTRY.
CONFIDENCE IS HIGH IN GRADUAL WARM UP TO ABOVE NORMAL LEVELS
DURING THE EARLY TO MIDDLE PORTIONS OF NEXT WEEK.
AVIATION /00Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 753 PM EDT THU OCT 15 2026
LIGHT SHOWERS OVERSPREADING THE EVENING WITH MAINLY MVFR
CEILINGS/VIS EXPECTED, WITH POTENTIAL DIPS TO IFR WITHIN HEAVIER
SHOWERS. ISOLATED STORMS ARE STILL POSSIBLE AT KFWA, BUT AS OF
THIS WRITING IT SEEMS THEY MAY FOCUS FURTHER SOUTH AND EAST OF
THE TERMINAL SO LEFT THEM OUT FOR NOW. EXPECT CONTINUED ON AND
OFF SHOWER ACTIVITY THROUGH THE DAY FRIDAY AS A SECONDARY TROUGH
MOVES THROUGH. OTHERWISE, INCREASING WINDS SHIFTING FROM S-SE TO
W-NW THROUGH THE PERIOD, WITH GUSTS UP TO AROUND 25-30 KNOTS
(STRONGEST AT KSBN).
IWX WATCHES/WARNINGS/ADVISORIES
IN...WIND ADVISORY FROM 1 PM TO 10 PM CDT FRIDAY FOR INZ103-203.
OH...NONE.
MI...WIND ADVISORY FROM 2 PM TO 11 PM EDT FRIDAY FOR MIZ177-277.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 AM EDT
FRIDAY FOR LMZ043-046.
GALE WARNING FROM 11 AM FRIDAY TO 2 AM EDT SATURDAY FOR LMZ043-
046.
DISCUSSION...MARSILI
AVIATION...MCD
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