486 FXUS63 KGRB 302016 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 216 PM CST Tue Dec 30 2025 Forecast discussion for routine afternoon forecast issuance .KEY MESSAGES... - A clipper system brings a round of fluffy snow through this evening. An inch or less is likely for most, with 1 to 2 inches expected in the Fox Valley, bayshore and lakeshore areas as well as across the lake effect snow belt in north-central Wisconsin. Minor travel concerns are expected. - An arctic cold front will bring additional light snow on Wednesday, with a dusting to a half inch anticipated in most areas. A couple inches of snow will be possible in Vilas County due to lake-effect. - Wind chills as cold as 15 to 25 below zero are possible New Years Eve night into the morning on New Years Day. && .DISCUSSION... Issued at 210 PM CST Tue Dec 30 2025 First Round of Snow: A fast moving Clipper system is currently bringing a swath of light snow and flurries to the region late this afternoon. Although moisture is meager, snow ratios are fairly high (upper teens) with fairly good dynamics in the form of a mid level PV anomaly and left-front quad of a 110 knot upper level jet. The high snow ratios and dynamics should lend themselves to most areas getting around a half inch of snow, with the Fox Valley, bayshore and lakeshore areas could get 1 to 2 inches. This will produce slick roads, especially in eastern Wisconsin, for the evening commute. Arctic Cold Front Snow: An arctic cold front will move into northern Wisconsin late tonight, then drop south through the rest of the region during the day on Wednesday. As this occurs, conditions will become more favorable for lake-effect snow (northwest winds and increasing instability over western Lake Superior with delta T values around 20) in north-central Wisconsin, with accumulations of 1 to 3 inches possible in Vilas County. Despite the arrival of a dry arctic air mass, will keep POPs higher than NBM (30-50%) given fairly strong dynamics with the frontal passage, increasing frontogenesis, a mid-level short- wave and the left-front quad of a 135 kt jet streak. Outside of the lake-effect region, only expecting a dusting to a half inch of powder in most areas. Brief Period of Cold: A fairly strong push of cold air arrives in the wake of the arctic front, with 800 mb temperatures dropping to 18 to 23 below zero Celsius across the region later Wednesday into Wednesday night. The combination of surface temperatures falling into the single digits below zero (except near Lake Michigan) and persistent northwest winds will result in wind chills of 15 to 25 below zero late Wednesday night into Thursday morning. These cold temperatures would likely impact any activities late New Years Eve into the morning hours of New Years Day. Cold Weather Advisories may eventually be needed for roughly the northwest half of the forecast area. Some moderation in temperatures is expected Thursday into Thursday night as incoming cloud cover prevents temperatures from tanking overnight, which will mean wind chill values will only fall to around 10 below zero across central and north-central Wisconsin Thursday night into Friday morning. Rest of the Forecast: No significant precipitation events are expected for the rest of the extended forecast period. After the brief shot of arctic air, a gradual moderate in temperatures is expected, with highs reaching the 20s by Sunday/Monday. && .AVIATION...for 18Z TAF Issuance Issued at 1133 AM CST Tue Dec 30 2025 VFR cigs were ubiquitous across the region late this morning, with some MVFR cigs across northern Door County. Upstream, an incoming Alberta Clipper was bringing an area of light snow and MVFR cigs across northwest Wisconsin. Light snow will overspread the region this afternoon, with mainly MVFR ceilings/vsbys. Potentially more significant snow should impact the region from mid-afternoon through early evening, with periods of IFR vsbys expected. The snow should taper off from west to east in the evening, though some lake-effect snow could persist in far NC WI. Additional snow is expected on Wednesday as an Arctic cold front sinks south through the region. Winds will be from the W-NW with speeds of 10 knots or less through tonight. Winds then increase to 10 to 20 knots with the Arctic front Wednesday from the NW. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Kurimski AVIATION.......Kurimski