327 FXUS63 KMKX 022021 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 321 PM CDT Mon Jun 2 2025 .KEY MESSAGES... - Smoke aloft from wildfires will continue to move through southern WI through Tuesday morning. Any surface smoke will be brief and very limited. - A line of thunderstorms is expected to develop along a cold front on Tuesday, moving eastward across the region between 3 PM and 10 PM CDT. Storms may become strong, with gusty winds as the primary threat, and locally moderate to heavy rainfall possible. Hail cannot be completely ruled out. - Showers and weaker storms likely to continue Tuesday night into Wednesday morning, gradually weakening. && .SHORT TERM... Issued 320 PM CDT Mon Jun 2 2025 Tonight through Wednesday: Broad high pressure over the eastern CONUS will work with Hudson Bay Canada low pressure to form a SW to NE oriented cold front over the northern Great Plains, which drifts west to east across our region late Tuesday afternoon through Tuesday evening. 500mb flow is robust and oriented perfectly parallel to the boundary, suggesting that linear thunderstorms are the prevailing convective mode (though some CAMs manage a few discrete cells ahead of the front). Thunderstorms are expected to cross the region between 3 PM and 10 PM CDT Tuesday in a west to east manner, posing a threat for gusty winds (level 2 out of 5 severe potential). The largely line parallel wind shear and mostly linear convective mode should strongly limit tornadic potential, though any eastward surges in the line (if present) would need to be monitored. CAPE is only marginally favorable for a hail threat (it can`t be ruled out, but isn`t the main concern). The risk level (2 out of 5) is highest in southwestern WI as seen in Today`s convective outlook, coincident with an earlier storm arrival (shortly after peak diurnal heating) and higher instability. Weaker storms and rain showers then continue into Tuesday night, tapering into Wednesday morning. Highs in the upper 60s to mid 70s behind the front Wednesday. Sheppard && .LONG TERM... Issued 320 PM CDT Mon Jun 2 2025 Wednesday night through Monday: Temperatures remain nearly steady state through much of the extended forecast, with highs confined to the 70s and upper 60s. A weak shortwave trough and corresponding Sfc low pressure pose a ~30-40% chance for showers and thunderstorms Thursday night through Friday, though the severe weather potential appears quite limited given the lack of warmth / moisture return. Sheppard && .AVIATION... Issued 310 PM CDT Mon Jun 2 2025 Wildfire smoke is expected to linger aloft through tonight, keeping skies hazy but not restricting surface visibility. Hence, VFR conditions and dry weather continue Tonight, with a light south breeze. Accelerating southwesterly winds aloft (roughly 40kt at 2,000 ft AGL) are expected to create a window of Low Level Wind Shear late tonight into early Tuesday morning. After sunrise Tuesday the south to southwest surface wind field will accelerate and become gusty by mid morning. A line of thunderstorms develops along a cold front west of the region Tuesday, sweeping eastward between 3 PM and 10 PM CDT. Initial cumulonimbus cloud bases are expected to be over 4,000 ft (VFR), with a threat for gusty winds and small hail. Continued shower / weak thunderstorm activity behind the initial line of storms is then likely to lower ceilings to Fuel-Alt MVFR levels into Tuesday night, with IFR possible over time. Gusty south to southwest winds ahead of the storms and the front (gusts 25-30kt) will veer north and decelerate behind the front. Sheppard && .MARINE... Issued 310 PM CDT Mon Jun 2 2025 South winds will continue to accelerate over the northern half of the lake, becoming gusty over the entire lake Tuesday morning and peaking in the afternoon (25-30 kt). This is in response to a Canadian cold front approaching from the northern Great Plains. The cold front will cross Lake Michigan Tuesday night into early Wednesday morning with breezy south winds ahead of the front veering northwest (and eventually due north) behind it. Weak high pressure will then settle over the lake later on Wednesday and into Thursday. Light and variable winds are forecast during this time. Sheppard && .MKX WATCHES/WARNINGS/ADVISORIES... WI...Beach Hazards Statement...WIZ052-WIZ060...4 AM Tuesday to 10 PM Tuesday. Beach Hazards Statement...WIZ066-WIZ071...4 AM Tuesday to 6 PM Tuesday. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...4 AM Tuesday to 10 PM Tuesday. && $$ 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