Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
590 FXUS63 KMKX 070300 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 1000 PM CDT Mon Oct 6 2025 .KEY MESSAGES... - Scattered to numerous rainshowers thru tonight (especially towards southeastern WI after midnight). A few rumbles of thunder possible towards southeastern Wisconsin. - Showers and weak storms move clear of the region by around 7 AM Tuesday. - Dry and cooler with a return to seasonal temperatures Tuesday through Thursday. - Areas of frost are forecast late Tuesday night and again Wednesday night mainly along and northwest of Highway 151. && .UPDATE... Issued 1000 PM CDT Mon Oct 6 2025 Aside from a broken line of showers progressing through southeastern WI at the moment, we are largely in a lull in the activity for the next 2 hours or so. After midnight tonight, a weak 500mb perturbation will work with an existing region of 850mb FGEN overhead to increase showers to numerous coverage, particularly over the southeastern half of the CWA, with a few rumbles of thunder possible in this same area. Showers and weak storms are then expected to diminish towards dawn Tuesday, moving clear of southeastern WI by around 7 AM CDT, leaving mostly dry weather for the AM commute. Sheppard && .SHORT TERM... Issued 344 PM CDT Mon Oct 6 2025 Tonight through Tuesday night: The cold front is currently located over far se WI with just isolated to scattered showers mainly behind the front. Deep surface based convection is occurring over Lake County, IL and will still be possible over Racine and Kenosha Counties through 6 PM CDT but chances are down to 40%. Farther to the north and west, post frontal showers and isold storms (30-50%) are forecast through sunset. Afterward, a 700 mb shortwave trough will approach from srn MN and nrn IA with 850 mb flow backing ahead of the trough. Well organized and fairly strong 850 mb frontogenesis will develop with 60-80% chances for showers tnt for much of srn WI. There remains very marginal elevated CAPE in the post frontal airmass so will still mention thunder. Temps will fall to 40s along and north of Highway 151 with lower to middle 50s to the south. Clearing skies are then expected Tue AM as dry air and subsidence arrives in the wake of the cold front and shortwave trough. High pressure will move along the US/Canadian border with the high arriving over nrn WI by 12Z Wed. Near normal high temps are forecast for Tue followed by middle to upper 30s inland from the lake for Tue nt. Areas of frost are likely along and north of highway 151 and a Frost Advisory may be needed. Gehring && .LONG TERM... Issued 344 PM CDT Mon Oct 6 2025 Wednesday through Monday: The GEFS and ECMWF Ens mean show good agreement on upper ridging taking hold as well as sfc high pressure slowly moving across the Great Lakes through Thu. Near normal temps are forecast along with patchy frost over portions of south central WI Wed nt. A weak shortwave trough will then traverse across the nrn Great Lakes late Thu nt and Fri with a weak sfc trough or cold front dissipating across srn WI. Only 10-20 percent chances for rain are forecast at this time. Upper ridging will then return to the Great Lakes for the weekend while upper troughing will prevail from the Pacific NW newd into central Canada. Sly winds and above normal temps will return to srn WI. The trailing and decaying cold front from low pressure over Canada may then reach srn WI on Mon. 20-40 percent chances of showers are forecast at this time. Gehring && .AVIATION... Issued 1000 PM CDT Mon Oct 6 2025 A lull in the shower activity over the next 2 hours (except for one broken line of showers towards far southeastern WI). Increasing coverage of rain showers after midnight tonight, especially further southeast in WI, with a few rumbles of thunder possible there. Predominantly IFR cloud ceilings towards southeastern WI due to the repeated showers, predominantly MVFR further north and west, with some VFR ceilings hanging on far northwest of the Madison metro overnight. Light north winds continue overnight. Showers and weak storms move clear of southeastern WI by around 7 AM CDT Tuesday, with cloud ceilings rapidly improving thereafter. Widespread VFR and dry weather expected throughout the daytime hours of Tuesday, with a light north to northwest breeze. Sheppard && .MARINE... Issued 344 PM CDT Mon Oct 6 2025 A Canadian cold front will continue to slowly progress southward across the south half of Lake Michigan, reaching the southern tip of the lake by early evening. Modest southwesterly winds will turn northerly behind the cold front passage and last through Tuesday night. The northerly winds will become breezy during this time over the south half of the lake with building waves. High pressure builds to around 30.4 inches into the Upper Midwest Tuesday and settles over the Great Lakes Region through midweek resulting in lighter, varying winds. Increasing southerly winds return for the end of the week as the high pressure gradually slides further east. For the nearshore waters from Sheboygan to Winthrop Harbor, waves may build to 4 to 5 feet south of Port Washington late Tuesday night and Wednesday morning. Gehring && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...None. && $$ Visit us at weather.gov/milwaukee Follow us on Facebook, X, and YouTube at: www.facebook.com/NWSMilwaukee www.x.com/NWSMilwaukee www.youtube.com/NWSMilwaukee