FXUS63 KIWX 120815 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 315 AM EST Fri Dec 12 2025 .KEY MESSAGES... - Dry for most areas into early Saturday. Some lake enhanced snow showers are possible along the shores of Lk MI with generally an inch or less accumulation. - Period of light snow Saturday afternoon (accumulations 1 to maybe 3 inches), transitioning to mainly lake effect snow showers Saturday night into Sunday (additional 1 to 3 inches NW). - Much colder air arrives Saturday, lingering into Monday. Wind chills of -15 degrees F or lower are likely Sunday morning southwest of Route 30. - Above freezing temperatures return Tuesday through Thursday with chances for rain. && .DISCUSSION... Issued at 314 AM EST Fri Dec 12 2025 Back edge of light snow, associated with the first of several clippers was moving across eastern IL. Far SW parts of the area (mainly portions of White and Cass county) did see some snow and based on INDOT cameras probably received at least a few tenths of new snow. Dry conditions will dominate most areas through Saturday morning as the main energy with the active northern stream trough passes mainly to the north of the area. A brief window of W to WNW flow will setup, with marginal Delta Ts and limited moisture/inversion heights resulting in a period of light snow tonight into early Saturday for portions of LaPorte, Berrien and maybe Cass counties. Accumulations, if any, should be an inch or less. Stronger clipper system and associated punch of arctic air, will take aim on the area late Sat morning into the afternoon hours with a burst of light synoptic snowfall. Overall accumulations look to be on the order of 1 to 2 inches (maybe a bit higher south of US-24). As 850 mb temps plummet to -20 C or lower Saturday night through Sunday night, a more pronounced lake response should commence with moderate lake induced instability and inversion heights 8-10 kft. Currently leaning towards potential accumulations of at least 1 to 3 and some potential for higher amounts depending on the final fetch. Headlines may be needed in this time frame, but confidence not high enough to hoist anything this far out. Lows in the single digits (above and below zero) are expected Saturday night, with the coldest temperatures across SW areas away from the lake effect clouds and precip. Sub zero wind chills are still in store for the entire area with -5 to -10 F under the cloud cover and a sharp gradient of -15 to -20 F where skies are clear. A wind chill advisory will likely be needed for these areas in the next issuance or 2. Skies begin to clear out across a larger area Sunday night into early Monday with overnight lows -5 to +5 F and wind chills roughly -10 to -15 F. A more pronounced shift in the patter will commence Monday night and persist through the end of the period with highs climbing above freezing during the day to allow for melting of the snowpack across the area. Aiding in the process with be a few chances for rain. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1233 AM EST Fri Dec 12 2025 Clipper system currently passing safely south of the terminals with just a 3kft stratus deck to contend with through the early morning. Brief scattering/lifting of the stratus deck is anticipated during the day before another shortwave arrives Friday night. This wave will bring more MVFR stratus and perhaps some light snow for KSBN being closer to Lake MI and the better forcing. Much lower confidence in snow at KFWA and will hold dry there for now. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...Small Craft Advisory from 10 PM this evening to 10 PM EST Sunday for LMZ043-046. &&$$ DISCUSSION...Fisher AVIATION...AGD