FXUS63 KIWX 241036 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 636 AM EDT Fri Oct 24 2025 .KEY MESSAGES... - Another cold night is expected tonight with lows everywhere in the low 30s. - Temperatures moderate slightly over the weekend but remain cool. - The next chance of rain arrives during the middle of next week. && .DISCUSSION... Issued at 252 AM EDT Fri Oct 24 2025 Blanket of lake effect clouds holding firm generally along/north of US-30 as expected and keeping temps generally at or above 40 there while temps in the SW drop into the low 30s under clear skies. This trend will likely continue through the morning hours given persistent, cool NW flow over the still very warm waters of Lake Michigan. Near surface flow does begin to back slightly by sunrise but forecast soundings show moisture-laden inversion around 5 kft holding firm through at least sunrise and likely a while beyond. Therefore, current frost/freeze headlines should continue to play out well with just a few minor variations in expected temps on the borders based on exact cloud cover. No changes to headlines necessary at this point. Clouds should slowly scatter through the day as winds slowly back and dry air advection takes an increasing toll. Our far N/NE counties may not entirely scatter out until almost sunset though. This will keep highs near 50F there while southern zones make a run at upper 50s. No major changes to the forecast for tonight. The night should at least start with mostly clear skies and light winds which will allow for quick and efficient radiational cooling. Low 30s still anticipated everywhere. Additional freeze headlines for IN/OH may be necessary for tonight if the growing season is not declared over based on temps this morning. Given current headlines and uncertainty with exactly how widespread freezing temps will be this morning, prefer to let day shift make the final call on if the growing season will officially end or if one more night of freeze headlines are warranted. (The growing season has already been declared over for all Michigan counties.) Saturday will feature dry conditions with light WAA pushing highs into the mid/upper 50s for the entire area. Lows Sat night may touch the mid 30s in our NE half but in all likelihood the growing season will be declared over by then. A fairly complicated upper air pattern then develops with troughs over the Southern Plains and Quebec with a third shortwave likely diving through the Great Lakes. Models continue to struggle with how this complex pattern will evolve early next week. There are some chances for precip by Mon and especially Tue but confidence is very low and did not deviate far from NBM initialization. High temps remain on the cool side of climo with generally mid 50s. Lows hover around 40F through early next week. && .AVIATION /12Z TAFS THROUGH 12Z SATURDAY/... Issued at 635 AM EDT Fri Oct 24 2025 Lake effect cloud cover will gradually erode today as approach of anticyclone will lead to continued diminishing low level winds. Strong mid level subsidence this morning will allow for continued lowering of inversion heights. Confidence in any short-lived MVFR cigs is low at this time with the lingering lake effect, but cannot completely out that potential at KSBN for a brief time this morning given lowering inversion heights. Otherwise, VFR conditions anticipated this period. Light west- southwest winds this morning will become west-northwest with diurnal mixing today, but prevailing wind speeds should generally be below 10 knots. Winds become light and variable tonight as the upstream anticyclone settles across the region. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...Frost Advisory until 9 AM EDT /8 AM CDT/ this morning forINZ008-009-012-014-017-018-116-203-216. Freeze Warning until 9 AM EDT this morning for INZ013-015-020- 022>027-032>034. OH...Frost Advisory until 9 AM EDT this morning for OHZ004-005-015- 016-024-025. MI...None. MARINE...Small Craft Advisory until 11 AM EDT this morning for LMZ043- 046. && $$ DISCUSSION...AGD AVIATION...Marsili