464
FXUS63 KIWX 181011
AFDIWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
611 AM EDT FRI SEP 18 2026
KEY MESSAGES
- BRIEFLY DRY AND LESS HUMID TODAY INTO THIS EVENING.
- SEVERAL ROUNDS OF RAIN AND EMBEDDED THUNDERSTORMS EXPECTED
THIS WEEKEND, POSSIBLY LINGERING INTO MONDAY. LOCALIZED
FLOODING WILL BE POSSIBLE WHERE THE HEAVIEST RAIN SETS UP.
- COOLER AND TRENDING DRIER TUESDAY THROUGH THURSDAY.
DISCUSSION
ISSUED AT 303 AM EDT FRI SEP 18 2026
A LOW LEVEL ANTICYCLONE TRACKING EAST THROUGH ONTARIO AND THE
NORTHERN GREAT LAKES WILL FUNNEL DRIER, LESS HUMID AIR INTO THE AREA
TODAY INTO THIS EVENING. ACTIVE PATTERN WITH SEVERAL ROUNDS OF RAIN
AND EMBEDDED STORMS THEN RETURN LATER TONIGHT THROUGH THE WEEKEND
AS ANOTHER BAROCLINIC ZONE AND UNSEASONABLY MOIST 2 INCH PWAT AXIS
SET UP OVER THE AREA. A PARADE OF CONVECTIVELY ENHANCED SHORTWAVES
AND BROAD WAA/ISENTROPIC UPGLIDE INTO THE FRONTAL ZONE WILL NO DOUBT
AID IN THE EXPANSION OF TRAINING ELEVATED CONVECTIVE EPISODES AND
TORRENTIAL RAINFALL.
A MODEL CONSENSUS FAVORS SATURDAY MORNING INTO EARLY SATURDAY
AFTERNOON FOR THE FIRST ROUND OF ELEVATED CONVECTION ON THE NOSE OF
A ~30 KNOT LOW LEVEL JET. HIGHER QPF/POPS ARE FAVORED WEST OF I-69
AND NORTH OF US 24 WITH THIS FIRST ROUND AS ACTIVITY MAY TEND TO
OUTRUN MORE FOCUSED LOW LEVEL CONVERGENCE WITH SOUTHEASTWARD
PROGRESSION.
A BRIEF LULL REMAINS POSSIBLE IN BETWEEN MID LEVEL IMPULSES SATURDAY
AFTERNOON-EARLY EVENING BEFORE ADDITIONAL BOUTS OF MORE ORGANIZED
RAIN/THUNDER SETTLE IN SATURDAY NIGHT INTO SUNDAY. THIS OCCURS AS A
WEAK SFC FRONTAL WAVE AIDS IN ENHANCING THE FGEN RESPONSE. HEAVIER,
TRAINING CONVECTIVE ELEMENTS REMAIN A CONCERN FOR LOCALIZED FLOODING
GIVEN THE FRONTAL FORCING AND MOISTURE RICH AIR MASS. A FLOOD WATCH
MAY BE NEEDED FOR PORTIONS OF THE AREA AT SOME POINT, BUT HELD OFF
FOR NOW PER COLLABORATION AND LINGERING MODEL SPREAD ON TIMING AND
LOCATION. PROSPECTS FOR ANY ISOLATED SEVERE STORMS ARE ON THE LOW
SIDE SOUTH OF US 30 OTHERWISE LATER SATURDAY AFTERNOON-EVENING AS
THE SFC BOUNDARY AND POTENTIAL FOR ANY SURFACE BASED CONVECTION
STRUGGLES TO REACH THIS FAR NORTH.
COOLER WEATHER REMAINS IN STORE FOR NEXT WEEK AS THE PRIMARY WESTERN
CONUS UPPER TROUGH RELEASES EAST, POTENTIALLY CLOSING OFF OVER THE
GREAT LAKES BY MIDWEEK. CONTINUED MOIST ISENTROPIC UPGLIDE OVER
THE SOUTHWARD SINKING FRONTAL ZONE KEEP CHANCES FOR SHOWERS THROUGH
AT LEAST MONDAY, WITH A TREND TOWARD DRIER WEATHER THEREAFTER AS THE
LEADING MOISTURE CHANNEL SHIFTS OFF TO THE SOUTHEAST.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 608 AM EDT FRI SEP 18 2026
CIGS MAY BOUNCE AROUND IN THE MVFR TO LOW VFR RANGE THROUGH
13-14Z AT KSBN BEFORE DRIER AIR MAKES BETTER INROADS MID MORNING
THROUGH THE REST OF TAF CYCLE WITH VFR CONDITIONS AND EASTERLY
WINDS UP TO NEAR 10 KNOTS. AT FWA, IFR STRATUS SHOULD MIX OUT TO
VFR BY MIDDAY WITH SIMILAR WINDS.
IWX WATCHES/WARNINGS/ADVISORIES
IN...NONE.
OH...NONE.
MI...NONE.
MARINE...NONE.
DISCUSSION...STEINWEDEL
AVIATION...STEINWEDEL
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