Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
461 FXUS63 KMKX 280857 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 357 AM CDT Sat Jun 28 2025 .KEY MESSAGES... - Some fog may develop early this morning across south central Wisconsin. - Heat index vales in the 95 to 100 degree range are expected on Sunday. - Thunderstorms are possible Sunday afternoon and evening, along and ahead of a cold front. Gusty winds are possible with the strongest storms. - Turning a little less humid through the middle of next week, with a more active weather pattern returning toward the end of the week. && .SHORT TERM... Issued 357 AM CDT Sat Jun 28 2025 Today through Sunday night: Some fog may develop across south central Wisconsin into the early morning hours, with light to calm winds and small dewpoint depressions. Confidence is low at this time, as there are some lingering clouds in the 2500 to 3500 foot AGL range that may limit this possibility over areas around and north of Madison. In addition, there is some high clouds from the convection in the Northern Plains that may move into the area into this morning. This may also limit fog development. The best chances will be in the Wisconsin River Valley and other low-lying areas. The low clouds may linger into the rest of the morning, before moving to the east or mixing out. The high clouds should be thin enough to allow for partial sunshine by late morning or afternoon, with diurnal cumulus clouds developing. Highs should get into the middle 80s inland, with southeast winds near the lake keeping highs in the middle to upper 70s. Some CAMs try to bring remnants of the convection southeast toward or into western portions of the area by middle to late afternoon. The low level jet should remain focused more to the northwest and north into today, so think any weakening showers and storms would remain in those areas. For now, kept forecast dry for this afternoon in the west. The low level jet remains focused to the north and northwest of the area tonight into Sunday morning, so most of the showers and storms associated with it should remain to the northwest and north. Kept small PoPs (20 percent) in far northwestern and western parts of the area later tonight into Sunday morning, just in case any remnant showers and storms hold together. It should be a very warm and humid day on Sunday, with 925 mb temperatures supporting highs around 90 degrees. Dewpoints in the lower 70s should bring heat index values into the 95 to 100 degree range for Sunday afternoon. The forecast heat index values are near the 90th to 95th percentile per the NBM, so no heat headlines will be issued at this time. Still, it will be a muggy day, so that will need to be messaged. CAMs are varying with timing and placement of showers and storms for Sunday afternoon into the evening. They generally develop along the weak cold front from central to southwest Wisconsin into northeast Iowa by middle to late afternoon Sunday. They should gradually work into south central Wisconsin by early Sunday evening. However, some CAMs have the activity weakening during the evening, with others dry for the area. The frontogenesis is robust, if it moves through the area. There are not much other features to help generate showers and storms besides a possible MCV feature from earlier convection to the west. Thus, forecast confidence remains low with what may occur during this period. There will be plenty of instability to work with, with mean layer CAPE above 2000 J/kg but with weak deep layer bulk shear of 10 to 15 knots. Thus, some gusty winds may occur with stronger storms and perhaps some hail. For now, will continue to monitor this storm potential for Sunday afternoon and evening, and hopefully gain some confidence in timing and impacts in later forecasts. Wood && .LONG TERM... Issued 357 AM CDT Sat Jun 28 2025 Monday through Friday: The precip forecast is uncertain for Monday, as it will depend on how Sunday plays out. If a remnant outflow boundary stalls over southern Wisconsin Sunday night, this may act as a focus area for shower and storm development on Monday, once the clouds clear out. Temperatures will depend on our cloud cover, but the dewpoints are expected to remain on the higher side. We will wait for the next upper trough to swing across the Upper Midwest and Great Lakes Monday afternoon and night in order to kick out some of the warmth and humidity. Drier conditions will move in Tuesday in the form of slightly lower dewpoints, but our temperatures may not drop much. This will hold through Wednesday. The upper ridge over the west will start to lean over into southwest Wisconsin Thursday into Independence Day. This puts us in a favorable position to receive a round or two of convection, as storms fire upstream and ride the ridge through central or southern Wisconsin. This may be very similar to this past week. Cronce && .AVIATION... Issued 357 AM CDT Sat Jun 28 2025 Some fog may develop across south central Wisconsin into the early morning hours. Confidence is low at this time, as there are some lingering clouds in the 2500 to 3500 foot AGL range that may limit this possibility over areas around and north of Madison. In addition, there is some high clouds from thunderstorms in the Northern Plains that may move into the area into this morning. This may also limit fog development. The best chances will be in the Wisconsin River Valley and other low-lying areas. The low clouds may linger into the rest of the morning, before moving to the east or mixing out. The high clouds should be thin enough to allow for partial sunshine by late morning or afternoon, with diurnal cumulus clouds developing. Light winds will become south today inland, with southeast winds for terminals near Lake Michigan by midday into the afternoon. Some clouds may linger into tonight, as winds shift to the south and remain light. Southwest winds should then occur on Sunday, with south to southeast lake breeze winds near the lake that could reach Milwaukee and Kenosha later in the day. There are chances for showers and storms Sunday afternoon mainly west of Madison, with better chances Sunday evening. Confidence is low in timing and impacts with the precipitation at this time. Wood && .MARINE... Issued 357 AM CDT Sat Jun 28 2025 Weak high pressure around 30.0 inches over the region will move east today, leading to light to modest west winds becoming south to southeast. Winds will become south and increase Saturday night into Sunday, as the high moves east of the region. A cold front will then move east across the region later Sunday night into Monday, with winds shifting to the west. Showers and some thunderstorms may accompany the frontal passage. The west winds should linger into the middle of next week. Wood && .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