Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
590 FXUS63 KMKX 180111 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 811 PM CDT Sat May 17 2025 .KEY MESSAGES... - Below-normal high temps continue through the middle of next week. - 15-30% chances for showers in southwestern Wisconsin Monday ahead of the next low pressure system. - Rain chances peak Tuesday / Tuesday night (45-85%) accompanied by breezy east winds as low pressure passes south of the region. Chances taper off into Wednesday (25-40%). A few rumbles of thunder may occur on Tuesday. - High temperatures rebound back toward normal by the end of the next week. && .UPDATE... Issued 811 PM CDT Sat May 17 2025 Low pressure will continue across srn Quebec tnt with a cold front extending wwd from it to nrn Lake MI and nrn WI. This front will weaken further as it slowly slides south into srn WI late tnt-Sun AM. A sfc ridge will then take hold for later in the afternoon while upper ridging continues aloft. The continued cyclonic flow, weak sfc convergence along the front, and relatively moist low levels should be able to maintain mostly cloudy skies tnt into early Sunday afternoon, then more of a clearing trend later in the afternoon. High temps in the 50s for the lake counties via nely flow, and well into the 60s over south central WI, still looks good for Sunday. Gehring && .SHORT TERM... Issued 410 PM CDT Sat May 17 2025 Tonight and Sunday: Gusty west winds subside late this evening into tonight. Low clouds linger at scattered to broken coverage, but expecting dry weather to continue. As high pressure builds into the Hudson Bay vicinity of Canada Sunday, slow and steady north winds are expected inland, with modest northeasterly winds (gaining momentum over the cold lake) pushing into eastern WI through the day as a weak backdoor cold front / lake breeze. Hence, high temps in the mid 50s Sunday by the lakeshore. Mid to upper 60s inland. Dry weather. Sheppard && .LONG TERM... Issued 410 PM CDT Sat May 17 2025 Sunday night through Saturday: Low pressure over the central Great Plains on Monday will track eastward through Illinois / Indiana through Wednesday. For Monday this will leave us with only 10-25% chances for rain in southwestern WI, otherwise mostly dry. Mostly cloudy skies and breezy northeast winds off of Lake Michigan will keep all of Wisconsin below seasonal normal temperatures, with inland highs around 60 degrees and lakeshore highs in the low 50s. East to northeast winds become even gustier for Tuesday, with widespread 45-85% rain chances (highest further south, closer to the passing low pressure). Rumbles of thunder may mix in with the rain at times, though our positioning north of the low pressure system and the cold water temperatures of Lake Michigan preclude any concern of severe weather. Mostly just a beneficial rainfall. 25-40% rain chances linger into Wednesday, tapering as time goes by. Breezy winds backing north-notheast. High pressure builds back into the region Wednesday night into Thursday, with mostly dry weather and temperatures beginning to moderate back up as north winds gradually subside. Developing low pressure over the Rocky Mountains and broad high pressure over the southeastern CONUS will leave our region with a relatively weak pressure gradient (and slow winds) late next week, with temperatures continuing to climb. A few shortwave troughs in the upper air pattern / weak surface lows (depending on the choice of model) merit some broad-brushed 15% precip chances, but dry for the larger fraction of the time period. Sheppard && .AVIATION... Issued 811 PM CDT Sat May 17 2025 Stratocumulus clouds and areas of MVFR Cigs will continue tnt- Sunday. Some partly cloudy skies will develop for Sunday afternoon. Gehring && .MARINE... Issued 410 PM CDT Sat May 17 2025 Open Waters / Synopsis: Breezy west winds continue across Lake Michigan this afternoon, veering northwest this evening and decelerating overnight as 30.4 inch high pressure over Canada moves toward the Hudson Bay vicinity. The approach of this area of high pressure will allow winds to taper during the second half of the overnight hours tonight. Winds will turn due northerly during the day on Sunday as high pressure pivots into far northern Ontario. Wind speeds will increase during the day on Monday as 30.5 inch high pressure lingers over the Hudson Bay vicinity and 29.4 inch low pressure forms in the central Great Plains. Brisk winds will continue into the day on Tuesday, shifting east-northeasterly as the aforementioned area of low pressure moves into the Ohio River Valley during the afternoon hours. The low will move into the Appalachian Mountains on Wednesday, resulting in a northerly wind shift across Lake Michigan. Given that low pressure will be approaching and passing to the south of the open waters, winds will be gusty on both Tuesday and Wednesday. Gales are not anticipated at this time, though trends will continue to be monitored in the coming forecasts. The approaching low will also bring chances for showers and isolated thunderstorms, with severe weather not expected. Winds will gradually taper Thursday into Friday, when 30.2 inch high pressure is forecast to settle into the western Great Lakes. Nearshore Zones: The ongoing Small Craft Advisory expires this evening as gusty westerly winds gradually subside. Gusty northeast to east winds are expected as low pressure passes south of the region Sunday night through mid week. A prolonged period of Small Craft conditions due to waves and wind gusts is expected. Winds and waves ramp down Thursday into Friday as high pressure builds in. Sheppard && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Small Craft Advisory...LMZ643-LMZ644 until 10 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