Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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470 FXUS63 KIWX 100612 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 112 AM EST Wed Dec 10 2025 .KEY MESSAGES... - Gusty southwest winds tonight becoming northwest behind a cold front on Wednesday (gusts 35-40+). - Periods of rain and snow late tonight into Wednesday. Wet snow accumulations (near 1") possible tonight north of US 30. Snow accumulations near 1" near Lake MI Wednesday afternoon- evening. Minor travel impacts possible. - The pattern remains active late this week into the upcoming weekend with cold temperatures and periodic snow chances. && .DISCUSSION... Issued at 242 PM EST Tue Dec 9 2025 A strong hybrid clipper system with a ~990 mb low pressure system takes an east-southeast track through southern WI and southern lower MI tonight into Wednesday morning bringing gusty winds and precipitation. The initial precipitation develops on the leading edge of a 50-60 kt LLJ later this evening into early Wednesday morning, especially along and north of the US 30 corridor. Model vertical thermal profiles suggest liquid/rain as the primary ptype for most. The exception appears to be far northeast IN, south- central MI and far northwest OH where a brief period of accumulating wet snow appears likely sometime in the 04-08z timeframe, best chances around Hillsdale/Angola/Coldwater where a sloppy inch or two of snow cannot be ruled out. Lower probability and concern for a brief period of freezing rain at onset elsewhere this evening as ground temperatures likely warm just above freezing. However, the recent cold stretch and snow cover could delay expected warming just enough for a quick glaze of ice mid evening into the early overnight (low confidence). Lastly, sfc wind gusts within the ramping LLJ should generally be limited to 30-35 mph in this WAA regime. Mid level dry slot briefly makes inroads later tonight through mid morning Wednesday with a trend toward a more showery/drizzle setup with temps in the mid-upper 30s. The system cold front and wrap around moisture then races southeast through the local area mid morning through mid afternoon on Wednesday. Gusty winds and snow showers, potentially squally in nature, will accompany this feature. There could be a 1-3 hour window where a few gusts push near wind advisory criteria with the frontal passage. A transition to lake effect snow showers/squalls in the CAA regime likely does bring some light snow accumulations and minor travel disruptions (vis restrictions) Wednesday afternoon- evening with an inch or two possible in northwest IN and southwest MI. The parade of clipper systems in energetic northwest flow will persist through the second half of the week into the upcoming weekend with periodic snow chances. These appear to be your more typical clipper systems that produce a rather narrow band of accumulating snows along a tight baroclinic zone. The first of these disturbances looks to zip through Thursday night into Friday morning. Latest model guidance does continue to suggest mid-level fgen snow clipping areas mainly southwest of US 30, though subtle adjustments north or south remain possible. Another one then follows in around Saturday-Saturday night per ensembles with additional snow accums in or near our forecast area. Sub-zero wind chills and LES the possible into Sunday behind this 2nd wave. This pattern does finally look to break just beyond this forecast period. && .AVIATION /06Z TAFS THROUGH 06Z THURSDAY/... Issued at 1252 AM EST Wed Dec 10 2025 Predominantly VFR/MVFR conditions to start the period at both terminals, deteriorating towards IFR for a time this morning. There is potential for LIFR visibilities at KSBN between 14-18z (prob30) but confidence wasn`t high enough for a tempo just yet. Rain/drizzle overnight will gradually change over to snow from west to east through Wednesday as temperatures fall behind a cold front, with mixing starting at around 13z at KSBN and 15Z at KFWA. Variable model guidance with this system with regards to visibilities/ceilings, particularly in the 14-19z time frame with everything from 500-2500 ft suggested with 1/2 to 6SM visibilities. Guidance was overly pessimistic with this system yesterday-and some of the lower guidance already too low as of this issuance. Went middle of the road and tried to highlight potential for the worst conditions with prob30 group for now. Light rain/drizzle over much of the area at the moment, with southwest winds gusting to around 25 knots. Winds shift northwest with gusts up to around 30kts through the afternoon. LLWS at both sites in the 50-55kt range through morning. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...Gale Warning until 7 PM EST this evening for LMZ043-046. && $$ DISCUSSION...Steinwedel AVIATION...MCD