Area Forecast Discussion
Issued by NWS Green Bay, WI
Issued by NWS Green Bay, WI
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728 FXUS63 KGRB 020905 AFDGRB Area Forecast Discussion National Weather Service Green Bay WI 405 AM CDT Sun Jun 2 2024 Forecast discussion for routine morning forecast issuance .KEY MESSAGES... - Patchy/areas of fog through around daybreak this morning, especially central and north-central Wisconsin where it could be locally dense. - Rain and some storms Monday. An isolated strong storm in the afternoon could produce gusty winds. - More strong storms are possible Tuesday afternoon into Tuesday night. Gusty winds and heavy rain will be the primary hazards. && .DISCUSSION... Issued at 403 AM CDT Sun Jun 2 2024 Short Term...Today...Tonight...and Monday Fog early today, then a mostly sunny and warm day. Showers and some thunder spreading from west to east on Monday. Fog as expected has become most dense over central Wisconsin where a Dense Fog Advisory remains in effect through 9 AM. Based on recent obs have expanded the advisory into Vilas, Oneida, Langlade and Waupaca counties. Elsewhere fog has been much more patchy with minimal fog thus far Green Bay into the Fox Cities. Fog will quickly diminish all areas after daybreak. Lingering stratus will transition to scattered cu in the aftn, but skies will be mostly sunny overall. High temps near 80 away from the Lake Michigan shoreline where readings will be limited to mid to upper 60s. Tonight will stay dry until very late when low pressure system and warm front begin to approach the western Great Lakes. A few showers may make it into central to north-central zones, but much better chances hold off til daytime on Monday. Expect swath of showers and embedded thunder to work across region on Monday, probably not arriving over northeast and east-central WI til afternoon. There are details to be ironed out in terms of where greater focus for storms will be with possible convective aided shortwaves, MCVs working in from the central Plains. Even so, stronger low-level jet, theta-e advection and jet entrance region should result in widespread showers over our area. Better chance for stronger storms will be in the afternoon southwest of AUW to OSH line as MLCAPES rise toward 1000j/kg and there would be increased effective shear from any convective shortwave. SPC has marginal risk on our southern doorstep which agrees with the expected pattern and majority of high-res CAMs. High temps will depend on how quick the showers move into the area and how widespread they are. Readings will range from around 70 north- central to the mid 70s southwest closer to the warm sector in the afternoon. Long Term...Monday Night Through Saturday An active pattern continues in the extended forecast as an upper trough lodges itself across northern CONUS, bringing through periodic rounds of active weather. Monday night through Tuesday... Although any strong storms are expected to depart the region by the evening hours, continued isentropic ascent overnight will sustain at least a few showers going overnight Monday into Tuesday. Although this could also hamper instability development later in the day on Tuesday, models do still develop fairly strong surface instability, upwards of 1500+ SBCAPE, as dewpoints push well into the 60s during the afternoon. Therefore, additional surface based thunderstorms are possible in the afternoon. The factors limiting severe weather however, are unimpressive mid- level lapse rates, a lack of bulk shear for organizing storms, and the delay in the cold front passage mentioned in previous forecasts; which is now expected to remain out west during our best diurnal instability and only make its way into northeast Wisconsin well into the overnight hours. Taken together, would expect pulse storms to be possible Tuesday afternoon and evening with brief strong wind gusts. Heavy rainfall will be a concern however, as these storms will be relatively slow moving and PWATS remain impressive for the time period. Finally, the passage of the cold front overnight will likely help sustain any ongoing rain and storms, furthering the heavy rain concern, but will likely not lead to widespread severe weather. Encapsulating all this, the marginal risk category for severe remains off to our west Tuesday while we are in the marginal risk for excessive rainfall, which makes sense. Rest of the forecast... The upper pattern will for the rest of the extended appears to slow down and stall out, favoring a continuation of periodic active weather over our region. The broad upper low that brought the cold front through the region appears to stall out over south- central Canada and the northern CONUS, resulting northwest flow and several rounds of relatively lighter active weather through the rest of the work week and into early next weekend. The good news here however is that this is not expected to be severe weather at this time, as cooler temperatures and drier air will limit any thunderstorm potential. && .AVIATION...for 06Z TAF Issuance Issued at 1045 PM CDT Sat Jun 1 2024 Conditions became increasingly more favorable for fog development during the late evening due to remnant low-level moisture, light winds, and partial clearing. Visibilities are expected to drop to at least IFR at most TAF sites, with LIFR vsbys possible at CWA and AUW where a Dense Fog Advisory is in effect from midnight to 9 AM Sunday. After fog burns away Sunday morning, expect prevailing VFR conditions as weak high pressure settles in across the region. Scattered daytime cumulus may develop across the TAF sites during peak heating early Sunday afternoon and linger through the evening, although cigs are expected to remain VFR. && .GRB WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory until 9 AM CDT this morning for WIZ005-010- 018-019-030-035>037-045. && $$ DISCUSSION.....JLA/Uhlmann AVIATION.......Goodin