Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
055 FXUS63 KMKX 120245 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 945 PM CDT Fri Jul 11 2025 .KEY MESSAGES... - The cloud to ground lightning risk will continue into the overnight hours. Rain will gradually taper off overnight. - Scattered thunderstorms expected Saturday afternoon and early evening. - Dry weather expected Sunday into early Tuesday, then turning warmer and more active mid week. && .UPDATE... Issued 945 PM CDT Fri Jul 11 2025 Active evening with a pesky supercell and a robust line of storms. The remnants of the line are now moving over the open waters of Lake Michigan, though a rather expansive area of stratiform rain remains. There is a sneaky lightning risk in this area of rain and will continue to mention the chance for thunder into the overnight hours. The shield of rain will gradually shift to the east and north, though with a trial of upper level vort maxes and boundaries around, redevelopment of scattered showers remains possible through daybreak. The forecast for Saturday is largely on track. A cold front will enter from the northwest and scattered showers and storms are expected during the afternoon into early evening hours. This round looks more hit or miss compared to the current widespread rainfall. Gagan && .SHORT TERM... Issued 314 PM CDT Fri Jul 11 2025 Rest of this Afternoon through Saturday night: Showers and thunderstorms have developed early this afternoon along an elevated frontal boundary, which is stretching from west to east across the central portion of the forecast area. Stronger activity so far has been across Iowa and far western Wisconsin, where instability and lift are stronger. More substantial, surface based activity is developing across central and east central Iowa, and this will progress eastward over the next few hours as well. The severe threat associated with this activity will largely be tied to the location of the surface front, which while somewhat defuse, appears to be located generally just north of the Wisconsin/Illinois state line. As low pressure over Iowa strengthens and lifts northeastward, this surface front should end up a little south of the I-94 corridor by early evening. Mid level lapse rates across this area will be weak, but substantial low level CAPE and sufficient 0-3 KM will present a wind and QLCS tornado threat with any organized, eastward surging line segments. This threat looks to reach the lakeshore area between 8 and 10 PM, before pushing east. In addition to the severe threat, heavy rain remains a concern. PWATs near 2 inches and a deep sub-freezing cloud layer will favor very efficient rainfall rates. Individual storms will be moving, but flooding concerns will ramp up for any areas that see multiple rounds of convection in a short time. The strongest convection looks to end by around 10 PM, though some storms may linger across central Wisconsin, tied to the location of the meso-low and shortwave. Other scattered showers may persist overnight. A few additional scattered thunderstorms are then possible on Saturday along an advancing cold front. Weak convergence along the front and poor upper level support suggest scattered coverage at best, with slightly higher potential (30%) over central Wisconsin. The front will clear the area by Saturday evening, with cooler and drier air building into the area. Boxell && .LONG TERM... Issued 314 PM CDT Fri Jul 11 2025 Sunday through Friday: Sunday looks to be a rather pleasant day, with highs in the low 80s and lower dewpoints. Warmer and more humid conditions return for Monday, with highs in the mid 80s. Couldn`t rule out a brief shower or two on Monday as a frontal boundary stalls out to our north, but most locations will remain dry. Temperatures will be back into the upper 80s on Tuesday, with dewpoints in the low to mid 70s, as stronger warm advection overspreads the region. Thunderstorms are then expected to develop later Tuesday to our north along the aforementioned front, with periods of showers and storms across the region Tuesday night and Wednesday, and potentially into Thursday, as the front wiggles around the area. As is usually the case with this type of set-up, the timing and location of individual rounds of showers and storms will be predicated on how earlier convection evolves, so predictability more than a day or so in advance is low. A stronger shortwave will push a more substantial front through the region late in the week, with cooler and drier high pressure looking to be favored as we head into next weekend. Boxell && .AVIATION... Issued 945 PM CDT Fri Jul 11 2025 Primary concern for the rest of the night will be lingering rainfall and occasional embedded lightning strikes and the risk for MVFR/IFR ceilings. The main line of storms has pushed over the lake, and an expansive stratiform area of rainfall is left in its wake. Overall rainfall is generally on the lighter side with pockets of MVFR visibility and IFR ceilings (though at this point not widespread). In general, guidance lowers ceilings into the IFR range at most locations during the overnight hours and showers gradually taper off and winds shift to the southwest. Heading into the daylight hours of Saturday, IFR/MVFR stratus will gradually lift/break up. There are signals for scattered showers and storms Saturday afternoon into the evening, though confidence is not high enough to include in the TAFs at this time. Looks like these storms will be a bit more hit or miss. Quieter weather finally settles over the region into Saturday night as the cold front passes and winds shift to the northwest. Gagan && .MARINE... Issued 314 PM CDT Fri Jul 11 2025 A broad trough of low pressure averaging 29.7 inches will lift from Iowa into the northern Great Lakes tonight into Saturday. Thunderstorms are expected across the lake tonight, some of which may have strong winds. Winds will be from the south over the southern half of the lake and from the northeast over the northern half of the lake through early evening, becoming southerly over the entire lake overnight. A cold front will then pass through the lake Saturday afternoon and evening, with winds turning westerly Saturday night. High pressure of 30.0 inches will move across the southern tip of Lake Michigan on Sunday, with winds turning southerly and southwesterly as the high moves east. Southerly flow is then expected into at least Monday, before a front becomes stationary over the central portion of the lake through mid week. Boxell && .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