Area Forecast Discussion
Issued by NWS Green Bay, WI
Issued by NWS Green Bay, WI
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800 FXUS63 KGRB 092048 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 248 PM CST Sun Nov 9 2025 Forecast discussion for routine afternoon forecast issuance .KEY MESSAGES... - Light lake effect snow showers will continue to impact the snow belt of north-central Wisconsin and the Door Peninsula. An inch or two of accumulations will be possible through late tonight, highest over the northwest part of Vilas County. - Snow showers, potentially producing low visibility, are possible across north-central and central Wisconsin outside of the main lake effect belt through early this evening. && .DISCUSSION... Issued at 247 PM CST Sun Nov 9 2025 A deep and anomalous upper-level trough is digging across the western Great Lakes this afternoon. This trough, combined with strong high pressure building in from the Dakotas, has tightened the pressure gradient across the region, leading to gusty northwest winds to 25 mph. The trough axis will shift east of the area tonight and Monday, allowing a surface high pressure ridge to build in from the west by late Monday. Short Term (This Afternoon - Monday)... The primary forecast concern revolves around lake effect snow showers. The most significant impacts were felt over Door County this morning, where a dominant lake-effect snow band set up and produced snowfall rates of over one inch per hour from Ephraim to Jacksonport. However, a slight backing of the low-level winds has since pushed this main band east of the peninsula. Renewed banding over the county has been disorganized and cellular, likely disrupted by daytime instability. With some dry air expected to work in from the northeast late this afternoon, robust reorganization of the band is not expected. Therefore, the Winter Storm Warning for Door County has been canceled. Across north-central Wisconsin, lake effect snow showers intensified around midday, particularly over Vilas County, though accumulations have generally underperformed so far. Scattered snow showers continue to develop across the western half of the forecast area this afternoon. While instability remains present, organized snow squalls are not expected, and the Winter Weather Advisory for Oneida County has also been canceled. As the upper trough shifts east tonight, lake effect parameters will become less favorable. Low-level winds will waffle between north and northwest, and rising mid-level heights and temperatures will lessen instability. Still, additional accumulations of 1 to 2 inches will be possible over northern Vilas County through Monday morning. Door County will continue to see scattered snow showers, though dry air and shifting wind directions will limit additional accumulations to an inch or less tonight. For Monday, the surface ridge axis moves in from the west. This will bring diminishing snow showers over the north and increasing sunshine across the area by the afternoon. Highs are expected to be in the 30s. Long Term (Monday Night - Saturday)... Flattened troughing will remain aloft over the region through Thursday. A brief wave of light warm advection snow is possible late Monday night into Tuesday morning, which could result in a dusting to perhaps a half-inch of snow, mainly over central and north-central Wisconsin. Another weak impulse could bring additional light snow into far northern Wisconsin late Tuesday night into Wednesday. Following this, gusty northwest winds are likely on Wednesday, with gusts potentially exceeding 30 mph. Otherwise, the weather looks quiet for the latter half of the work week. Upper-level ridging is forecast to slowly build in from the west, allowing temperatures to moderate by the end of the week. The next chance for precipitation appears to be next weekend. Models show a developing trough ejecting from the west, which could bring a system with rain and wind into the area. && .AVIATION...for 18Z TAF Issuance Issued at 1124 AM CST Sun Nov 9 2025 Clouds and snow showers will continue to increase in coverage across the area this afternoon. Snow showers will have the most impacts over north-central WI (KAUW, KCWA, KRHI) with brief periods of MVFR or IFR visibility possible. Confidence is lower for SHSN impacts at KGRB/KATW/KMTW, but maintained the prob30 groups. Gusty NNW winds gusting 15-25 KTS are expected this afternoon. Snow showers will end by 02Z at the terminals, with ceilings rising to VFR at most sites late in the evening and overnight. MVFR ceilings will return to all TAF sites on Monday morning (after 09Z-12Z). The lowest conditions are expected at KRHI, with MVFR ceilings (BKN013-017) forecast after 11Z. Outlook: Lingering MVFR ceilings will likely depart on Monday afternoon leading to VFR conditions for Monday evening. && .GRB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 6 AM CST Monday for WIZ005. && $$ DISCUSSION.....MPC AVIATION.......MPC