FXUS63 KGRB 231734 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 1234 PM CDT Sun Aug 23 2026 Forecast discussion for routine afternoon forecast issuance .KEY MESSAGES... - Dry through Monday, with rain chances (50-80%) Tuesday afternoon through Wednesday evening. The risk of widespread severe weather is low. - Chilly with lows into the 30s north-central WI tonight. Otherwise temperatures most of this week will be near or slightly above normal. && .DISCUSSION... Issued at 1234 PM CDT Sun Aug 23 2026 Near term through Monday...NW flow persists to the west of deep troughing over the central and eastern Great Lakes. Cooler air aloft the warmer lakes and daytime heating will result in blossoming cu this afternoon. Moisture appears too shallow to conjure up any showers, though a few sprinkles could occur. Northern Door most favored for those. Northwest winds will be gusty again this afternoon, but will back off quickly this evening. As winds become light and skies clear, temps will drop quickly, with mid 30s in favored cold spots of north-central WI, low-mid 40s central WI into far northeast WI, and upper 40s to near 50 from the Fox Valley to the lakeshore. Some very patchy ground fog will be possible late tonight into Monday morning, especially across central and northern WI. It could be cool enough for sheltered areas in the far north to see some brief patchy frost late tonight. Mostly sunny on Monday with light winds. Showers and some storms Tuesday afternoon through Wednesday evening...Sharp shortwave trough with cold front drop into northern MN Tuesday afternoon before shifting across WI and MI through Wednesday. Pooling instability along the front late Tuesday may allow a small severe risk into far northwest portions of cwa very late Tuesday afternoon into Tuesday evening. Various ML sources point to this, but even so, stronger signal stays farther into northwest WI and northern MN. That said, showers and storms will probably not completely die off later Tuesday night as they move east given a persistent LLJ and some elevated instability with the stronger system. Does appear that models are coming into better agreement with faster fropa on Wednesday, pushing the primary severe risk farther east. Enough cool air aloft with the trough to result in chance pops northeast and eastern WI through peak heating on Wednesday. Thus, suppose an isolated strong to severe storm is not off the table. Chances for showers and storms on Thursday have decreased as core of upper trough and cooler air aloft has shifted farther north. Pops for Thursday now sitting at less than 10 percent. Extended...Next chances for showers and storms (20-40%) eases back into the area from the southwest for the weekend as flow aloft becomes more zonal. Early look, but signal for greatest instability and severe/heavy rain potential remains southwest plains to the upper mississippi river valley. Temperatures...After the chilly conditions tonight, temperatures the rest of the week look to be near normal or slightly above normal. Warmest days with highs in the low-mid 80s would be Tuesday and/or Wednesday ahead of and near the frontal boundary moving through. Warmest night in the 60s much of the area will be Tuesday night with clouds, showers and some wind. Lows could drop back into the 40s again late this week over the north. && .AVIATION...for 18Z TAF Issuance Issued at 1234 PM CDT Sun Aug 23 2026 Other than patchy ground for (mainly MVFR vsby) central and north-central WI late tonight, plan on VFR conditions through the TAF period. Higher based cu will clear out tonight, with just wispy cirrus at times. Skies will remain mostly clear on Monday, with little in way of cu compared to last two days. Northwest winds will gust between 13-18 kts this afternoon, then become light and variable this evening. Winds on Monday will be light, topping out at 5 to 10 kts during the afternoon. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....JLA AVIATION.......JLA