Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
494 FXUS63 KMKX 171353 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 853 AM CDT Mon Aug 17 2026 .KEY MESSAGES... - Showers and thunderstorms return to the forecast Tuesday evening. - Dry and pleasant conditions Wednesday through Thursday. Rain chances return Friday. && .UPDATE... Issued 851 AM CDT Mon Aug 17 2026 Forecast remains on track early this morning. Valley fog has lingered a touch longer than anticipated near the Wisconsin River, so have added some additional fog mentions through 11 AM to align with observational trends. Expect fog will have dissipated thereafter. Pleasant conditions prevail through the remainder of the day as high pressure moves into the Upper Mississippi Valley. Quigley && .SHORT TERM... Issued 1158 PM CDT Sun Aug 16 2026 Rest of Tonight through Tuesday: Fog is expected in the Wisconsin River Valley and also in other low lying areas west of Madison overnight. An area of clouds is working its way down Lake Michigan tonight and there is also a wind shift to the northeast. The lake breeze will help keep the winds out of the NE for much of the day while inland areas will have generally NW winds. With high pressure spreading into Wisconsin, expect mostly sunny skies today with scattered diurnal cumulus clouds. Look for increasing clouds Monday night as winds become southwesterly in return flow around the high. Lows will be in the lower 60s. A weak trough crossing WI on Tuesday may be able to trigger a few showers and thunderstorms in the afternoon and evening. Given dewpoints in the upper 60s just ahead of this front, we will have a little instability to work with. A mid level shortwave and a southerly (fairly weak) low level jet will provide synoptic support and also a little wind shear for those storms as well. A few stronger wind gusts are possible. Cronce && .LONG TERM... Issued 1158 PM CDT Sun Aug 16 2026 Wednesday through Saturday: We will settle into a new weather pattern for the latter half of the week. Ridging over the western states and troughing over the east will put southern WI in an area with persistent northwest flow. Weak ripples in the flow could bring a chance for showers, but we will mainly be on the cooler/drier side of the front from Wednesday through Friday morning and our forecast is dry. Highs will be in the upper 70s each day with lows in the 50s. A weak front is expected to drop through southern WI Friday afternoon or night and could bring a round of showers and a few storms. Cronce && .AVIATION... Issued 550 AM CDT Mon Aug 17 2026 A convergent band along the lakeshore produce swath of clouds ranging from 4-5kft along with pockets of 1.5-2.5kft resulting in MVFR conditions. However, expect the lower flight conditions to improve through the morning, but a scattered to broken deck of mid-level clouds persist through mid morning. While we have seen an isolated light shower/sprinkle associated with these clouds this morning, could see additional widely isolated showers/sprinkles through the afternoon. However, not expecting much of any impacts as anything that may develop will be brief and transient. Otherwise, high pressure building into the region will help keep winds lighter and predominately out of the north, but vary at times through the day and into Tuesday. Wagner && .MARINE... Issued 1158 PM CDT Sun Aug 16 2026 An area of high pressure will build in from the northern Great Plains late tonight into Monday, bringing light and variable winds through monday night. A slow- moving cold front will approach from the northern Great Plains Tuesday into Wednesday, bringing increasing southwest winds and chances for thunderstorms. Tuesday evening and night appears most favored for storm potential, with storm chances expected to move well south of the waters on Wednesday. High pressure will move through the western Great Lakes Wednesday through Thursday, with light and variable winds prevailing across the waters. The next thunderstorm chances arrive Friday afternoon and evening, when the next cold front is expected to move across Lake Michigan. Cronce && .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