Area Forecast Discussion
Issued by NWS Green Bay, WI
Issued by NWS Green Bay, WI
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654 FXUS63 KGRB 060925 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 425 AM CDT Thu Jun 6 2024 Forecast discussion for routine morning forecast issuance .KEY MESSAGES... - Breezy conditions are expected today and Friday, with gusts to 30-35 mph. Wind gusts to 40 mph are possible today in/around any shower activity. - Conditions hazardous to small craft are expected today and Friday. - Showers are expected at times today, especially over northern WI. Additional showers are possible at times this weekend, with a chance of thunderstorms on Saturday. && .DISCUSSION... Issued at 424 AM CDT Thu Jun 6 2024 Short Term...Today...Tonight...and Friday A pattern more akin to fall arrives today, bringing breezy and showery conditions. Things dry out on Friday but it will remain breezy. Main forecast concerns revolve around shower chances, whether we will get a stray storm today and how high winds will gust. Showers Trends / Thunder Threat / Winds: Dry conditions, along with some clearing, will start off the day. However, clouds will spread back into the area from northwest to southeast through the morning, reaching the Fox Valley and lake shore last. Deeper moisture and another shortwave will rotate through the area today, as the parent upper low drifts across Lake Superior. This will produce scattered to numerous showers over northern WI later this morning and afternoon, with more spotty coverage as you work further south. Coverage will decrease in the late afternoon and evening, with mainly dry conditions expected overnight into Friday as some drier air and ridging briefly works into the western Great Lakes. A stray thunderstorm is possible late this morning and afternoon as MUCAPE climbs to around 200 J/kg, But with chances staying around 10%, opted to not include in the forecast. Better chances look to be in the U.P. where some lake boundaries will aid in convergence and slightly more instability is forecast. West-northwest winds will gust up to around 30 mph today, with some better mixing in/around any shower bringing down winds up to 40 mph at times, as winds at 5000 ft will remain around 35 kts. The gustiness will ease this evening and overnight, then west- northwest winds will gust to around 35 mph again on Friday. Temps / Humidity: Have leaned toward the cooler guidance today as clouds/precip will hold down temps. This is pretty much in line with the previous forecast, holding highs in the mid and upper 50s in north-central WI and the lower and middle 60s over eastern WI. If the rain/clouds hold off a little longer, temps will get into the upper 60s over the south/east. Lows tonight will drop into the mid 40s to mid 50s. Highs on Friday will rebound back into the mid 60s to low 70s as WAA pushes in from the west. It will be much less humid today into Friday as dewpoints remain in the 40s and low 50s. Long Term...Friday Night Through Wednesday Main focus from this forecast period revolves around the precipitation chances for the weekend. Biggest change from the previous forecast is the strength of the closed low progged to sit over the eastern Great Lakes/southeastern Ontario/southern Quebec region, which has trended weaker. This will allow for any shortwaves circulating around the closed low or any embedded shortwave energy riding along the mean northwest flow present over the Upper Mississippi Valley to more easily move over the area. That being said, the next chance for precip looks to occur sometime on Saturday associated with shortwave energy riding along the northwest flow in combination with a shortwave trough circulating around the closed low over southern Quebec. While most locations across the forecast area look to receive some precip, models are not in agreement with which feature will be the stronger of the two, causing uncertainty with who will see the better chances. Thunderstorms will be possible, but will be dependent on if precip occurs during the morning or peak heating, as some models are suggesting. Additional showers are possible on Sunday as energy from the shortwave trough continues to circulate over the western Great Lakes. These showers will likely be diurnally driven and should stay confined to northern WI. Dry conditions return for Monday with upper-level ridging progged to build over the Upper Mississippi Valley. The trailing trough looks to bring the next chance for showers and possible storms on Tuesday, followed by dry weather for midweek. && .AVIATION...for 06Z TAF Issuance Issued at 1030 PM CDT Wed Jun 5 2024 Scattered showers and thunderstorms will end overnight as a strong upper level disturbance moves away from the area. A few surface wind gusts to 35 knots possible with the thunderstorms. VFR conditions are expected outside any convective activity. Some clearing is possible late tonight. If there are some clear skies Thursday morning, skies will become cloudy again by afternoon, with scattered showers, especially across northern Wisconsin. MVFR ceilings are likely west of a IMT to AUW line, with VFR ceilings further east. && .MARINE... Issued at 424 AM CDT Thu Jun 6 2024 Have expanded the Small Craft Advisory to include all of our area as soundings showing better mixing near Lake Michigan today. Highest winds look to be south of Sturgeon Bay. Offshore winds will keep waves mainly under 2 ft. Similar set up on Friday with gusts to around 25 kts likely, so another Small Craft Advisory may be needed. && .GRB WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION.....Bersch/Kruk AVIATION.......RDM MARINE.........Bersch