Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
803 FXUS63 KMKX 111117 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 617 AM CDT Fri Sep 11 2026 .KEY MESSAGES... - Patchy fog in low-lying areas early this morning, burning off shortly after sunrise. - Trending drier, but still cannot rule out some isolated showers and a rumble of thunder into Saturday morning, especially in southwestern Wisconsin. - Additional showers and storms expected Sunday night through Tuesday morning. A few stronger thunderstorms are possible. The potential for heavy rainfall is increasing, especially Monday and Tuesday. - Seasonable conditions may return midweek. && .UPDATE... Issued 618 AM CDT Fri Sep 11 2026 Forecast remains on track. Patchy fog in low-lying areas will burn off shortly after sunrise. Expecting highs around 80 degrees with southerly winds. Diurnal cumulus are expected, with no rain expected. MH && .SHORT TERM... Issued 1200 AM CDT Fri Sep 10 2026 Today through Saturday night: High pressure will continue to slide eastward this morning, meanwhile a surface low is progged to develop and track across central Canada. As a result, southern WI will be placed in between these systems and expect to see southerly winds pick up through the day today. Will see a bit of WAA with the southerly flow and temps be a degree or a few warmer today than yesterday. However, moisture advection will be lacking so will feel more comfortable humidity wise. OVernight temps will also be warmer with lows dipping into the lower 60s into Saturday morning. May also begin to see increasing cloud cover overnight aiding in the warmer temps. Then the low pressure to our north will gradually work its way into the Hudson Bay region and drag the cold front across WI on Saturday. May see some showers along the front upstream make it in our western areas, given the lack of appreciable PWATs (less than 1.5 inches), expect a mostly dry frontal passage as this trend continues on the 00z CAMs. Otherwise will see west to northwesterly wind shift behind the front later Saturday followed by cooler, more fall like temps in 50s again. Wagner && .LONG TERM... Issued Issued 1200 AM CDT Fri Sep 10 2026 Sunday through Thursday: High pressure returns to the region for Sunday resulting is a pleasant seasonal end to the weekend with highs only in the 70s and lows dipping into the 50s and maybe even cracking into the upper 40s. This high pressure is not expected to hang around for too long and quickly shifts east overnight Sunday into Monday as the pattern becomes a bit more active for the start of the week. Upstream a trough is progged to lift across the Northern Rockies and Northern Plains through the day. Ahead of it, looking at low-level WAA to gradually increase along with southerly surface winds and moisture advection to lift into southern WI during this time. Models continue to favor increased PoP chances (+40%) along the low-level WAA and surface warm front overnight Sunday through the day on Monday. Then later Monday night into early Tuesday expect the cold front to swing through the region as the main low traverses across the James Bay region. While, this places southern WI in the warm sector of this system, a bulk of the latest mid-range guidances is keeping the upper-level dynamics to our north. Meanwhile any convection will be driven by low-level WAA, and unseasonable stronger LLJ, and timing of the cold frontal passage, which this far out is tough to pinpoint exact details. Also given the trend for more midday precip chances, may end up limiting instability building into southern WI and paired with later overnight/early morning timing of the cold front across our neck of the woods, may ultimately limit our thunderstorm potential with this early week system. Nevertheless, still plenty of time for things to shift and if we see this system slow down and the 40-50 kt LLJ scenarios materialize, it may be enough for a few stronger storms and potentially minor flooding concerns for portions of southern WI. Will continue to monitor over the coming days, but it does bear watching. Behind the start of the week system, things are progged to settle down a bit toward the middle of next week as high pressure is progged to filter in behind it and bring a cooler airmass to the area. Wagner && .AVIATION... Issued 618 AM CDT Fri Sep 11 2026 Patchy fog may still progress across terminals in eastern Wisconsin, but is expected to be short-lived and low-lying. Fog will burn off shortly after sunrise. Winds will become southerly after sunrise, becoming steady around 10 kt during the afternoon hours. Gusts around 18 kt are possible along the Lake Michigan shoreline north of MKE. Diurnal cumulus around 5000 ft are expected. Winds will remain steady and southerly overnight, with increasing high clouds. Isolated showers and thunderstorms become possible in southwestern Wisconsin going into early Saturday morning along a cold front. Winds turn west, then northwesterly Saturday as the cold front moves southeastward. MH && .MARINE... Issued Issued 1200 AM CDT Fri Sep 10 2026 High pressure along with light and variable winds will linger over the Great Lakes into this morning. Then expect the high pressure to shift into the eastern Great Lakes with south to southwesterly winds picking up over Lake Michigan through the day as low pressure works its way into the Hudson Bay. While could see some small craft conditions north of Port Washington, the strongest gusts are expected to occur across the northern third of Lake Michigan this afternoon into Saturday and may briefly approach gale force at times. The low pressure will gradually slide eastward through the weekend and drag a weak cold front across the Upper Great Lakes region on Saturday shifting winds to the west-northwest by Saturday night. Will then see winds gradually lessen through the day Sunday as high pressure builds across the northern Plains and into the Upper Great Lakes through Sunday evening. Another low pressure then develops across the Canadian Plains and tracks across Ontario for the start of the week. This will bring a return of increasing south-southwesterly wind over Lake Michigan ahead of this systems cold front, but timing and gusts will depend on the strength of the low pressure and cold front. Wagner && .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