Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
857 FXUS63 KMKX 300150 AAA AFDMKX Area Forecast Discussion...UPDATED National Weather Service Milwaukee/Sullivan WI 850 PM CDT Thu May 29 2025 .KEY MESSAGES... - A backdoor cold front should bring good chances (40 to 60 percent) for showers and thunderstorms Friday afternoon and evening. Some storms may produce gusty winds and hail. - Smoke from wildfires in south central Canada may move through the area Friday into the weekend. There is some potential for the smoke to reduce visibility and cause air quality issues. && .UPDATE... Issued 850 PM CDT Thu May 29 2025 Isolated showers will linger into late evening, with mainly dry weather then expected overnight. Partly to mostly cloudy skies along with somewhat milder temps aloft than last night should result in lows right near normal tonight. No significant updates to the forecast are anticipated for the remainder of the night. DDV && .SHORT TERM... Issued 319 PM CDT Thu May 29 2025 Tonight through Friday night: A few showers developed along the lake breeze this afternoon. The updrafts are not being sustained long, and there has not been any lightning yet. Expect any showers to diminish with the loss of daytime heating early this evening. While the diurnal cumulus clouds will dissipate, some mid level clouds should linger overnight as the upper level low pressure trough finally begins to exit. Lows will be in the lower 50s. As the upper low exits and high pressure wedges into WI on Friday, warmer temps on northwest winds will spread into southern WI. Highs Friday will approach 80. The westerly breeze will help keep the lake breeze at bay, so lakeshore areas should see highs around 70. Smoke from Canadian wildfires is expected to expand into central WI by midday Friday and across most of southern WI Friday afternoon. We are seeing much fewer cumulus clouds under the smoke in North Dakota, northern MN and southern western Ontario via visible satellite this afternoon. With the smoke expected overhead in southern WI tomorrow, this will likely be the case. With inhibited diurnal cu, shower development outside of the main frontal forcing is lower. A mid level shortwave trough dropping across central and eastern WI Friday afternoon along a weak baroclinic zone is expected to be enough forcing for thunderstorms. The baroclinic zone that should be parked over northeast WI is expected to drop west- southwest through southern WI in the wake of this shortwave trough, aka backdoor cold front. Southern WI should have around 500 j/kg of CAPE (models vary a lot but dewpoints should be on the low side) built up in the afternoon, and there should be modest shear right along the front. Therefore, scattered storms are expected along the front. A few strong storms are possible, which could produce gusty winds and small hail. Storms will diminish as they trek inland toward Madison by mid evening. Cronce && .LONG TERM... Issued 319 PM CDT Thu May 29 2025 Saturday through Thursday: Slightly cooler temps are expected Saturday, especially near Lake Michigan. Winds will be lighter out of the north, except east near the lake. Diurnal cu are expected well inland, west of Madison, where a weak shortwave should trek down along the MN/WI border. A few showers with isolated thunder are possible there during the late afternoon. Models have been trending westward with the location of these shower chances. Clear skies Sat nt will allow for temps to drop into the mid 40s toward Sheboygan to the lower 50s in southwest WI. Sunday is another day of quiet weather with sunshine and a lake breeze. Warmer temps in the upper 70s are expected well inland. The GFS tries to generate diurnal showers west of Madison, but this seems overdone. Warmer and more humid conditions will arrive in southern WI early next week. Showers and thunderstorms are possible at times Tuesday afternoon through Friday as low pressure approaches from the Northern Plains. Cronce && .AVIATION... Issued 850 PM CDT Thu May 29 2025 Light and variable winds this this evening will become westerly to around 5 knots by later tonight, picking up from the northwest during the day tomorrow. Wind gusts of 20 to 25 knots are likely by the afternoon, easing during the evening and then becoming light and variable overnight as high pressure moves in behind a cold front. At least SCT mid to high level clouds are expected tonight into Fri morning. Should see diurnal cumulus around 4-5 kft late tomorrow morning through the afternoon hours. Still looks like a sold chance for showers and thunderstorms mid tomorrow afternoon into the evening as the front drops northeast to southwest through southern Wisconsin. Could see a stronger storm or too produce some gusty winds and hail. DDV && .MARINE... Issued 319 PM CDT Thu May 29 2025 High pressure centered over the northern Plains will continue to bring light winds across much of the Lake tonight. Southwesterly winds in the northern third will continue as low pressure continues to pivot northeastward through northern Quebec. A cold front from this low pressure system will progress south-southwest across Lake Michigan Friday afternoon and evening, bringing a quick wind shift to northerly. In addition, scattered thunderstorms may develop along this front, especially across the southern half of the lake. High pressure will then build into the region and linger through the weekend, bringing light and variable winds. Cronce && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...None. && $$ 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