Area Forecast Discussion
Issued by NWS Green Bay, WI
Issued by NWS Green Bay, WI
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330 FXUS63 KGRB 210439 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 1039 PM CST Thu Nov 20 2025 Updated aviation portion for 06Z TAF issuance .KEY MESSAGES... - Patchy fog, light rain, and drizzle continues through late this evening. - Precipitation chances return late Monday through late Wednesday. - Near normal to above normal temperatures expected through early next week, turning cooler (below normal) Wednesday into Thursday. && .DISCUSSION... Issued at 342 PM CST Thu Nov 20 2025 Tonight...Foggy and drizzly conditions under overcast skies prevailed across the region for much of the day, ahead of an approaching cold front. This cold front is expected to sweep southeast across the area between late this afternoon through late this evening. Given upstream observations and radar imagery indicated light rain was falling along the front, decided to include low chance PoPs (15-20%) across the area this evening. The front will also push the fog out of the area upon arrival. Clearing skies will be a bit delayed following the frontal passage, potentially not clearing until Friday morning. Given the uncertainty in clearing, increased low temperatures by a degree or two with values ranging from the mid 20s to low 30s. Rest of the forecast...Surface high pressure moves into the region for Friday into Saturday, keeping conditions dry. A shortwave and weak cold front look to move across Upper Mississippi Valley Saturday into Saturday night, but the main shortwave should stay far enough north to limit precip potential for the forecast area. High pressure moves back into the region Sunday into Monday, bringing the return of dry weather. Long-range models indicate the next chance for precip will be sometime from Monday night through Wednesday, and possibly lingering into Thursday. The first feature of interest is the remnants of an upper-level low/trough lifting into the region late Monday into Tuesday from the southwest U.S., with another upper-level low/trough from the Northern Plains late Tuesday into Wednesday. P-type with the first part appears to be rain as warmer air will prevail; the second part looks to have more of a wintry mix due to colder air dropping into the area from Canada. && .AVIATION...for 06Z TAF Issuance Issued at 1039 PM CST Thu Nov 20 2025 Main aviation concern for the overnight period will be low cloud trends as the arrival of drier air continues to break up the lingering low stratus deck in the region. As a result, lingering MVFR ceilings will be in the region early on but conditions should lift to VFR relatively quickly. As a result of the rapid clearing overnight, brought back in a brief mention of fog for the central Wisconsin TAF sites in the early morning hours, but would expect any fog coverage to be fairly patchy and lift shortly after sunrise. Light winds and clear skies are then expected for majority of the day Friday. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Kruk AVIATION.......Uhlmann