FXUS63 KMKX 030241 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 941 PM CDT Fri May 2 2025 .KEY MESSAGES... - Additional scattered shower activity expected this afternoon/early evening. - Mostly dry on Saturday, with a few showers/sprinkles possible over far southern WI. Shower chances increase for eastern WI on Sunday. - Warm up expected through the middle of next week. && .UPDATE... Issued 935 PM CDT Fri May 2 2025 An area of slow moving showers continues to develop on the western edge keeping showers over the same areas of the CWA. This is largely occuring over Dane county and to a lesser degree Columbia, Green and Rock counties as well. More isolated to scattered shower activity outside of those counties. This is very likely due to the shortwave trough aloft slowing down over the region as it slides through tonight. Over the course of the night the upper trough will push out with showers likely dissipating given the lack of forcing with moisture in the midlevels also pushing out by daybreak Saturday morning. No thunder expected with these shower and dry conditions expected Saturday for the most part. Kuroski && .SHORT TERM... Issued 255 PM CDT Fri May 2 2025 Tonight through Saturday night: As the shortwave trough swings across the Midwest through the afternoon/evening, expecting scattered light showers to fill in along the axis of the elongated vorticity max. This shower activity looks to be spotty in coverage and generally looking at lighter amounts with totals of a few hundredths to maybe a tenth or two of an inch at most. Will see chances diminish later this evening/overnight as the trough axis slides east- southeastward before stalling. Expecting mostly dry conditions overnight into Saturday as broad surface high pressure builds across the Upper Great Lakes region. While cloud cover lingers tonight, clouds are progged to begin to break up and scatter out for Saturday and expecting temps to warm into the upper 50s and break into the 60s for inland southern WI tomorrow. Meanwhile easterly flow off of Lake Michigan, which water temps sit between 39-43F, will keep temps "cooler by the Lake" with daytime temps in the upper 40s into the low 50s. Nightly lows are looking chilly tonight and Saturday night. Lows tonight look to be a tad bit higher given the lingering cloud cover insulating the area with lows in the upper 30s and low 40s. Saturday night looks chiller given clearer skies and light winds. Lows look to dip more into the upper 30s and cannot rule out the potential for some patchy frost to develop as some locations may cool a bit more toward the mid 30s range. Wagner && .LONG TERM... Issued 255 PM CDT Fri May 2 2025 Sunday through Friday: While we are looking at a gradually warming trend through the extended period, it may a bit slower as we saw with earlier runs. Prior days' models were progging an upper-level omega black type setup with the Upper Midwest under the ridge, which is not that common for this time of year, however, the pattern has shifted and looking more at a retrograding cutoff low pattern into the start of next week. There is consistency between the model clustered analysis of this setup with the cutoff low over the lower Ohio River Valley wobble back westward Sunday through Monday. With this placement southern WI will be on the north side of this system bringing prevailing easterly flow keeping temps cool, especially along Lake Michigan and some scattered shower activity. While cooler in the east, inland areas of southern WI do look to warm up a bit more into the 60s during this timeframe. May see some lingering showers into Tuesday, but the cutoff low looks to progress eastward toward the middle of next week with upper- level ridge quickly building across the Midwest. With the building ridge, warmer conditions are expected with temps in the upper 60s and approaching the lower 70s through the middle of next week. However, uncertainty remains fairly high given the variability within the long range models and ensembles during the spring season along with another upstream trough that is looking to lift into the region from the Plains toward the later half of next week. Wagner && .AVIATION... Issued 940 PM CDT Fri May 2 2025 An area of slow moving showers continues to develop on the western edge keeping showers over the same areas. This is largely occuring over Dane county and to a lesser degree Columbia, Green and Rock counties as well. More isolated to scattered shower activity outside of those counties. This area of showers is expected to gradually migrate east northeast before dissipating late tonight into early Saturday morning. CIGS across southeast WI remain primarily VFR with periods of MVFR CIGS mixing with areas northwest seeing MVFR CIGS primarily though areas with the rain showers are seeing CIGS fall to IFR. IFR CIGS will gradually push further in tonight. The east will hold off the longest but will eventually see the MVFR CIGS push in overnight tonight. Some MVFR VSBYS will be possible with heavier showers but are largely expected to remain VFR through the forecast period. MVFR CIGS will linger through parts of Saturday morning before gradually clearing out into the afternoon, hanging in the west the longest. VFR conditions will return by the mid to late afternoon across southern WI. Kuroski && .MARINE... Issued 255 PM CDT Fri May 2 2025 Low pressure continues to lift northeastward across Quebec through this evening. Then high pressure will continue to expand across the Western Great Lakes tonight, strengthening a bit by Saturday morning. This high pressure will sit over the Western Great Lakes region into early next week. However, will see low pressure centered over OH/WV wobble back westward at times through Monday bringing northeast- northerly winds across Lake Michigan with gustier conditions across the southern half through the weekend. With the gusty onshore flow and building waves, expecting to small craft conditions for nearshore waters south of Milwaukee on Saturday. Could see additionally small craft conditions develop for Sunday as well. Otherwise, occasional showers and patchy fog will also be possible across Lake Michigan through the weekend. Wagner && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Small Craft Advisory...LMZ645-LMZ646...10 AM Saturday to 7 PM Saturday. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSMilwaukee www.twitter.com/NWSMilwaukee www.youtube.com/NWSMilwaukee