Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
848 FXUS63 KMKX 010913 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 413 AM CDT Tue Jul 1 2025 .KEY MESSAGES... - Chances for thunderstorms at times Wednesday afternoon into Thursday evening. Gusty winds, small hail and locally heavy rainfall possible with any stronger storms, if they form. - Very warm and humid conditions for Independence Day and Saturday, with heat index values in the middle 90s or possibly higher. - Small chances for thunderstorms Independence Day into Friday night, with better chances Saturday into Saturday night. && .SHORT TERM... Issued 413 AM CDT Tue Jul 1 2025 Today through Wednesday night: High pressure will remain well to the southwest of the region today into Wednesday. Dry conditions are expected today into tonight, with west to northwest winds. Highs should reach the lower to middle 80s today. There should be a southeast lake breeze later this afternoon from Milwaukee southward, so temperatures may cool down a bit there. Lows in the lower to middle 60s are expected tonight. Northwest flow at 500 mb on Wednesday into Wednesday night may allow for a weak shortwave trough or two to shift through the region. The low level jet remains to the west of the area later Wednesday into Wednesday night, which may provide some warm air advection and moisture for showers and storms in that area, closer to the surface warm front. This activity may drift into the area Wednesday night, but probably will be weakening with loss of daytime heating. Forecast soundings become uncapped with peak heating, with around 500 to 1000 J/kg mean layer CAPE and 25 to 30 knots of deep layer bulk shear. There could be a few showers and storms that occur in the afternoon and evening hours, perhaps along a possible lake breeze boundary or shifting southeast into the area with any shortwave trough activity. Kept PoPs generally around 20 percent for now during this period. Gusty winds, small hail and locally heavy rainfall are possible with any stronger storms, if they form. Highs should reach the middle 80s Wednesday, with lows in the middle 60s Wednesday night. Wood && .LONG TERM... Issued 413 AM CDT Tue Jul 1 2025 Thursday through Monday: High pressure will remain parked over the Ohio River Valley Thursday. A warm front is expected to sharpen over the state during the afternoon, leading to some troughing over our CWA. This may allow for low end shower and thunderstorm chances Thursday afternoon and evening, with the NBM painting 15 to 20 percent PoPs over most of the area. This activity will likely be diurnally driven and tied to any wiggles that can develop in the 500mb flow aloft. Gusty winds, small hail and locally heavy rainfall may occur with any stronger storms, with the expected instability and bulk shear values. The warm front is expected to lift north Friday, ushering in a hot airmass for the 4th of July. Highs will be in the upper 80s to low 90s amid dewpoints that will return to the low 70s. Heat indices may approach 100 over some inland spots of southern WI. A few pop up thunderstorms may occur Friday afternoon and evening, but the bulk of the thunderstorm activity should be over Iowa and the northern Mississippi River Valley, where the core of a low level jet is expected to be focused. Saturday, heat will remain in place for most of the day, until a cold front approaches during the late afternoon into the evening hours. Showers and storms are expected to form along the front and sink south southeast across the state. Locally heavy rainfall may occur during this time. Models then diverge somewhat Saturday night as the front moves in. The ECMWF clears the front for Sunday, but the GFS stalls the cold front over southern WI, as a surface low deepens over Iowa and kicks through on Sunday. This leads to more prolonged shower and storm chances into Sunday afternoon/evening. Trends will be monitored for better agreement toward the end of the extended period. CMiller && .AVIATION... Issued 413 AM CDT Tue Jul 1 2025 High pressure will remain well to the southwest of the region today into Wednesday. Dry conditions are expected today into tonight, with modest west to northwest winds. There should be a southeast lake breeze later this afternoon for the Milwaukee and Kenosha terminals. Scattered diurnal cumulus clouds are expected as well. Light winds tonight will become west and modest once again on Wednesday. There may be another southeast lake breeze by later Wednesday afternoon for Milwaukee and Kenosha. There may be a few showers and storms that develop Wednesday afternoon and evening, perhaps along the lake breeze boundary or shifting southeast into the area. Kept out of TAFs for now due to low confidence in them occurring. Wood && .MARINE... Issued 413 AM CDT Tue Jul 1 2025 West to northwest winds are expected into today across the lake. They will weaken and become southwest in the afternoon across northern portions of the lake, with lighter winds to the south. Winds will turn back to the southwest to west tonight into Wednesday night, as weak high pressure of 30.0 inches moves through the Ohio Valley. Light winds Thursday should become south Friday and increase into Saturday, as a warm front pushes north through the region. There are chances for thunderstorms Wednesday afternoon and evening across the lake. Gusty winds and small hail are possible with the stronger storms. There are additional chances for thunderstorms Thursday afternoon and night, mainly over southern portions of the lake. Gusty winds and small hail may occur with stronger storms. There are mainly small chances for thunderstorms Independence Day into Friday night, with better chances Saturday into Saturday night. Wood && .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