Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
616 FXUS63 KMKX 092019 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 319 PM CDT Wed Jul 9 2025 .KEY MESSAGES... - Mostly dry conditions expected into tonight. Some fog may occur inland from Lake Michigan and in the Wisconsin River Valley. - Storm chances (30-40%) return Thursday afternoon and evening as an MCV moves through the upper Mississippi Valley. - Heat and humidity ramp up Friday into Saturday, along with the next widespread chances (~60-75%) for showers and thunderstorms. - Brief break from the humidity on Sunday, with muggy conditions and afternoon storm chances returning Monday-Tuesday. && .SHORT TERM... Issued 245 PM CDT Wed Jul 9 2025 Tonight through Thursday night: A few showers can`t be ruled out along a combined lake breeze/sfc trough this afternoon along the Wisconsin/Illinois border. Otherwise most of the area should remain dry. Tonight, patchy fog is anticipated inland from Lake Michigan and in the Wisconsin River Valley. Tomorrow, models have ramped up chances (now 30-40%) for rain during the afternoon compared to previous forecasts. This is owed to an MCV from dying convection in Iowa Thursday morning, moving overhead by Thursday late afternoon and evening. PVA associated with this feature will kick off shower and thunderstorm activity over the Upper Mississippi Valley during the early afternoon, with this activity translating east into Thursday evening. While widespread severe weather is not expected model soundings depict modest mid-level lapse rates around 7 C/km amid SBCAPE around 2000 J/kg and dry low- levels. The steep lapse rates would support hail, provided the storm doesn`t collapse first amid the weak effective shear around 20 knots. Any collapsing storms may pose a localized downburst threat with high winds. CMiller && .LONG TERM... Issued 318 PM CDT Wed Jul 9 2025 Friday through Wednesday: Still a bit of uncertainty with model disagreement in the extended period, but the general consensus is that a warm front is expected to lift north over the area by Friday morning. This will usher in a more humid air mass. There may be a few showers/storms along the initial push of WAA Friday morning. An elongated trough is then expected to kick off thunderstorm activity Friday evening along the Mississippi River and that activity will work east into the overnight hours, generally weakening as it travels east. The trough will slowly swing through on Saturday as a cold front. With its slow movement, there may be a enough time for some destablization in southeast Wisconsin, and a second round of thunderstorms may form Saturday afternoon before exiting east over Lake Michigan. The cold front will then pass Saturday night, with less humid and quieter conditions expected Sunday. A warm front is then expected to approach Monday, bringing back humidity and chances for storms Monday afternoon and Tuesday. CMiller && .AVIATION... Issued 231 PM CDT Wed Jul 9 2025 Winds will remain northerly this evening, and will slowly come around to easterly and southeasterly by daybreak on Friday. Low clouds are not expected to return, but some patchy fog may develop inland from Lake Michigan and in the Wisconsin River Valley overnight. Conditions will remain dry. Tomorrow, scattered thunderstorms look possible during the late afternoon and into the evening. CMiller && .MARINE... Issued 230 PM CDT Wed Jul 9 2025 High pressure will linger over the Upper Great Lakes into at least Thursday night. Breezy north winds over the southern half of the lake will give way to generally light and northerly winds tonight through Thursday. A few thunderstorms may move over the southern half of the Lake Thursday night. A warm front will then lift north Friday morning, change winds to southerly over the lake. Winds remain light until they turn southwesterly Saturday ahead of an approaching cold front, where gusts may reach 20 knots. Winds then ease and become westerly following the frontal passage Saturday night into Sunday. CMiller && .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