Kettlebowl Snow Report

322 FXUS63 KGRB 030716 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 216 AM CDT Thu Sep 3 2026 Forecast discussion for routine morning forecast issuance .KEY MESSAGES... - First round of thunderstorms will move across the area this morning into early this afternoon. Some of the storms could become severe with damaging winds and large hail along and south of Highway 29. - There may be a lull or a break in the thunderstorm activity during the afternoon, another round of strong or severe thunderstorms is possible again late this afternoon and tonight. - Above normal temperatures and periodic rain/storm chances will continue into the weekend. && .DISCUSSION... Issued at 215 AM CDT Thu Sep 3 2026 Another warm early September morning with temperatures in the 60s to lower 70s. Patchy fog developed in some spots and will monitor the lakeshore where some patchy dense fog may be possible on Lake Michigan where recent upwelling has cooled off water temperatures. Complex forecast this morning dealing with potential for strong or severe thunderstorms at times through late tonight. First round of thunderstorms expected to move across the area this morning into early this afternoon. Looking at two signals for this to happen. Latest models indicated scattered thunderstorms will develop between 08z and 11z across central into east-central WI in response to a 40 knot/850 warm advection on a low level jet. Also watching convection developing across southern Minnesota and northern Iowa that will make its way eastward into our area later this morning. Bufkit soundings at Green Bay indicated 40-50 knots of 0-6 km shear, surface base CAPE of 1,000-1,500 J/Kg with most unstable CAPE values around 2,000 J/KG. Some of the storms could become strong or severe with damaging winds, large hail and torrential rainfall this morning. There will likely be a lull or break in the thunderstorm activity this afternoon. With the best instability to our south, scattered thunderstorms may redevelop during the peak heating of the day across central into east-central WI closer to the best instability. Some of these storms could become severe as well. The plot thickens tonight with a complex of thunderstorms developing across the Upper Midwest. The latest Canadian/ECMWF/NAM/GFS model would suggest a complex of thunderstorms would work into the area during the late evening and overnight hours. However, there are a few meso models would suggest development would occur during the evening closer to the better instability and then drop south into southern WI. There are periodic chances of thunderstorms while above normal temperatures will continue Friday into early next week as the summer time pattern continues. && .AVIATION...for 06Z TAF Issuance Issued at 1053 PM CDT Wed Sep 2 2026 A rather complex TAF period with uncertainty regarding fog, low clouds and shower/storm chances overnight into Thursday. The simple part is late this evening where VFR conditions will prevail as mainly mid/high clouds drift across the region. The light winds, clear skies will allow for some fog to form, but guidance not very bullish on anything widespread or dense, with the higher chances (under 30% for under 3 mile vsby) over eastern WI. Have included mainly MVFR BR for now and will monitor fog trends. Low clouds are also possible early Thursday morning, with some guidance showing a 700-2000 ft deck, but again, not much agreement to have much confidence this will occur. Finally, the shower/storm threat is quite muddled, but latest guidance is increasing the coverage of with elevated convection possible as early as 07-09z across central and east-central WI, with a larger area possible after 12-13z Thursday. Depending on what occurs with those area, another round of showers and storms may or may not occur Thursday afternoon and evening. The end result will be plenty of TEMPO and PROB30 groups to account for the more likely periods of storms, but adjustments will be needed as the picture will hopefully become a little clearer. There remains a low-end ~20% chance that a storm becomes strong to severe with strong wind gusts and hail being the main impacts along with heavy downpours. Wind will remain fairly light away from any storm. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Eckberg AVIATION.......Bersch