Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
936 FXUS63 KMKX 261943 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 243 PM CDT Thu Jun 26 2025 .KEY MESSAGES... - Strong to severe thunderstorms are expected this afternoon and evening. Initial storms this afternoon will include a tornado threat, with strong winds becoming more likely with storms during the evening. - Somewhat cooler and relatively quiet weather expected Friday and Saturday, before temperatures turn much warmer/more humid on Sunday. - A cold front will bring temperatures back to around average for much of next week. && .SHORT TERM... Issued 243 PM CDT Thu Jun 26 2025 Rest of this Afternoon through Tomorrow: Main focus for this afternoon and evening will be severe weather potential. As of 2 PM, a warm front stretched across south central Wisconsin, generally just north of the I-94/US 18 corridor, curving back southeastward near Lake Michigan. As low pressure along the Iowa/Minnesota state line moves east- northeastward, this warm front will continue to slowly move northward. Convection should expand along the warm front this afternoon, though the spatial extent is still in question given the relatively weak lift. That said, anything that becomes rooted in the boundary layer will have a very unstable airmass to work with, with MLCAPE in excess of 2000 J/KG. There is also a substantial amount of low level CAPE, with 0-3 KM values between 100 and 200 J/KG. While Low level shear isn`t terribly impressive, the strong low level instability and localized increase in helicity associated with the warm front may be sufficient for a tornado threat with this afternoon`s convection, along with a few strong wind gusts. Weak mid level lapse rates and high freezing levels suggest that while a few instances of severe hail are possible, it should not be widespread. Later this evening focus will then shift to a line of storms moving in from the west. These will be more likely to contain damaging wind gusts compared to the afternoon convection, along with a somewhat lower tornado threat. Any eastward surges in the line, especially if collocated with the warm front or an outflow boundary, will still pose a risk for QLCS circulations, however. Storms will gradually weaken with eastward extent this evening, with the severe weather risk expected to largely dissipate by midnight. A few showers may linger into Friday morning, but otherwise most of the day on Friday should be dry. Highs tomorrow will be cooler, with upper 70s to around 80 expected. Winds will turn more northwesterly by afternoon helping to usher some lower dewpoints into the region as well. Boxell && .LONG TERM... Issued 243 PM CDT Thu Jun 26 2025 Tomorrow Night through Thursday: High pressure will sink south into the region late tomorrow night, setting the stage for what should be a fairly pleasant Saturday. Highs Saturday will range from the low to mid 80s, warmest southwest of Madison, with dewpoints in the low to mid 60s. A few showers or thunderstorms will be possible on Saturday near the state line, as a shortwave ripples through. Thunderstorm chances then increase area-wide late Saturday night and especially Sunday as a cold front sharpens to the northwest. This looks to pass through the area Sunday night, with an associated increase in PoPs through the afternoon and evening hours Sunday. Ahead of the front, a very warm and humid day is expected, with highs Sunday around 90. A Heat Advisory may eventually be needed for parts of the area, as heat indices will top out around 100. A few days of northwest flow will bring highs back to more average values, with highs in the low to mid 80s, and overnight lows in the low 60s. Dewpoints are also looking more tolerable, with values in the low to mid 60s most days. Boxell && .AVIATION... Issued 243 PM CDT Thu Jun 26 2025 Convection is starting to develop across the area this afternoon, with scattered thunderstorms expected through the afternoon hours. Later this evening, additional storms will arrive from the west, likely in the form of a line or broken line. Strong winds will be possible with both this afternoon and evening`s storms, along with reduced visibility and ceilings. Convection will persist into this evening, but will gradually weaken over time. Showers and low ceilings may persist into early Friday morning, before more quiet weather arrives for the day Friday. Boxell && .MARINE... Issued 243 PM CDT Thu Jun 26 2025 Low pressure of 29.8 inches will move across the Iowa and Minnesota border today, reaching Wisconsin tonight. A stationary front will stay parked over the southern end of the lake into this evening with southerly winds south of the boundary and north to northeast winds north of the boundary. As the surface low approaches tonight, winds will come around to southwesterly over the whole lake and thunderstorms are expected over much of the open waters. The low is then expected to pass early Friday morning, dragging a cold front over the lake. Winds will become westerly and northwesterly early Friday, becoming northerly Friday night as high pressure of 30.0 inches moves through the area. Winds return to a southeasterly to southerly direction Sunday as the high moves east of the region. 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