


Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
617 FXUS63 KMKX 070855 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 355 AM CDT Mon Jul 7 2025 .KEY MESSAGES... - Patchy fog possible through daybreak. - Small Craft Advisory & high swimming risk conditions continue through mid-morning over far southeastern Wisconsin. - Drier and more comfortable conditions expected through this afternoon. - Shower and thunderstorm chances (~30-55%) return Tuesday, though an all-day washout is not expected. - Additional shower and thunderstorms forecast Friday through Saturday ahead of the next disturbance. && .SHORT TERM... Issued 355 AM CDT Mon Jul 7 2025 Today through Tuesday Night: Synopsis/Mesoanalysis: 3 AM surface observations show an area of high pressure centered over the southern Hudson Bay. An affiliated surface ridge extends from said surface high into southern Wisconsin, which has allowed winds to go light and variable across most of the area. The light winds, combined with clear skies away from the state line, have allowed for noticeably cooler overnight temperatures mostly in the upper 50s and low 60s. Low clouds are apparent in satellite from Darlington east to Racine, where temperatures have remained a touch milder. Areas of patchy fog remain possible through daybreak within these low clouds, in addition to any locations that decouple under mostly clear skies. Areas along the Kettle Moraine and west of Madison will be most favored for patchy fog. Drier and more comfortable conditions are anticipated today as high pressure slides into the western Great Lakes. Currently apparent in water vapor imagery over southern Saskatchewan, an upper trough will progress across the Lake Superior & Michigan vicinity late tonight through Tuesday evening. Accompanied by a weak surface front, the feature will bring the next chances for showers and thunderstorms to southern Wisconsin from Tuesday morning through Tuesday night. Neither severe weather nor an all-day washout is expected. Higher than usual uncertainty remains regarding the precise locations, timing, and coverage of storms on Tuesday, with trends being monitored in the coming forecasts. Storms will gradually work east of the region Tuesday night into early Wednesday morning. Today: Affiliated with approaching high pressure, noticeably drier air will lead to more comfortable conditions for most. Abundant sunshine will lead to still warm high temperatures, with highs ranging from the upper 70s to low 80s away from Lake Michigan. Expect largely rain-free conditions, though there is a very small chance (~10% or less) of an afternoon shower or thundershower in the Wisconsin Valley. Withheld any mentions in the overnight update given these low probabilities, but will nevertheless be monitoring trends through today. Winds will remain breezy through mid-morning over southeast Wisconsin, resulting in a lingering high swimming risk at Milwaukee, Racine, and Kenosha County beaches. Have thus extended the Beach Hazards Statement through 10 AM in these locations. Continue to exercise extreme caution if heading lakeside early this morning in southeast Wisconsin. Tonight Through Tuesday Night: An encroaching upper trough & weak surface front will bring the next chances of showers and storms to the area. Precip could begin as early as predawn Tuesday in areas north and west of Madison, with 30-55% PoPs overspreading all of southern Wisconsin after sunrise. Noted above, forecast confidence remains low regarding the precise timing, location, and coverage of storms during this time frame, with each available CAM depicting different solutions. The wide amount of spread in the guidance appears linked to the positioning of the weak surface boundary, which is likely to be heavily influenced by the evolution of showers & storms developing in the Northern Plains this afternoon and evening. The further east storms make it into the Mississippi Valley tonight, the further east the surface boundary will be positioned by daybreak Tuesday. Further influences from any lingering MCV`s will also play a role in the evolution of storm development. Thus expect areas of showers and storms to be around the area late tonight through Tuesday evening, though their coverage & locations will be heavily dependent on the overlap of the aforementioned forcing mechanisms. A few storms could produce brief heavy downpours and gusty winds, though more organized severe weather is not anticipated at this time. Will continue to monitor trends through today. Quigley && .LONG TERM... Issued 355 AM CDT Mon Jul 7 2025 Wednesday through Sunday: Upper-level trough is expected to slide east by Wednesday, but some models hint at the cold front and some of its shower activity lingering in southern portion of the CWA Wednesday morning. Otherwise Wednesday/Thursday is progged to be less active as an upper-level ridge works its way across the Northern Plains/Canadian Plains. Meanwhile southern WI looks to be sandwiched between a surface high to the the north and a stalled frontal boundary to the south through Thursday, which will bring prevailing easterly winds and slightly milder, near normal temps. Given the pattern with lingering moisture and nearby forcing, cannot rule out a few stray showers/storms at times through midweek. Temps look to warm up by the end of the week as the upper-level ridge slides east and southerly flow advects in warmer temps ahead of an upper-level trough. Continue to see models vary on the time of this trough trekking across the Upper Midwest with the 00z long range runs leaning more into the start of the weekend compared to previous runs. However, this would be another window for increased shower and thunderstorm chances given the influx of moisture accompanying the warmer temps. Wagner && .AVIATION... Issued 355 AM CDT Mon Jul 7 2025 Areas of scattered low clouds have formed early this morning, particularly across the Wisconsin River Valley and southeastern Wisconsin. Said clouds have resulted in reported CIGs between FL008 and FL015 at affected stations, resulting in pockets of MVFR to IFR flight categories. Clear skies and VFR prevail at other locations unaffected by low clouds. Have accounted for observational trends through sunrise at the southern Wisconsin terminals, with JVL, UES, and ENW the most likely terminals to see continued impacts. With high pressure gradually working in from the west, do continue to monitor for some patchy fog potential along the Kettle Moraine and in the Wisconsin Valley through sunrise. Thus can`t rule out brief periods of VIS reductions at UES through daybreak, though forecast confidence is too low to justify any mentions in the 06/09Z updates. Anticipate that any patchy fog developing in the Wisconsin Valley will remain far enough west to cause any VIS impacts at MSN or JVL. Any lingering low CIG and VIS readings will quickly improve after sunrise, resulting in a return of VFR flight categories at all southern Wisconsin fields. Quigley && .MARINE... Issued 355 AM CDT Mon Jul 7 2025 With 1018 mb high pressure positioned over near the Hudson Bay and 1009 mb low pressure centered over Ontario, breezy north-northeast winds continue across the open waters this morning. Winds will gradually taper this afternoon as a second area of 1016 mb high pressure moves into the western Great Lakes from the Great Plains. Said area of high pressure will cross Lake Michigan tonight, allowing winds to turn light and variable across the open waters. Winds will shift out of the south-southeast during the day on Tuesday as a broad area of 1014 mb low pressure moves into the Upper Mississippi River Valley. The low will pull a weak surface front across Lake Michigan Tuesday night, resulting in a northerly wind shift. Areas of showers and thunderstorms will accompany the approaching boundary, with severe weather not expected at this time. North to northeast winds will remain entrenched through Thursday. Winds will turn out of the southeast on Friday as a second area of 1010 mb low pressure moves into the Great Plains. The low`s approach will bring additional chances for showers and thunderstorms to the open waters Friday into Saturday. Breezy northeast winds continue in nearshore zones through this morning as low pressure lingers over southern Ontario. Have extended the Small Craft Advisory through 10 AM CDT from North Point south to Winthrop Harbor, where elevated wave heights will linger slightly longer than initially forecast. Expect that the Small Craft Advisory will be able to expire as scheduled at 7 AM between Port Washington and North Point. Winds and waves will gradually taper this afternoon through tonight as high pressure moves in from the Upper Mississippi River Valley. Scattered showers and thunderstorms are forecast Tuesday afternoon and evening as a weak surface front crosses Lake Michigan. Severe weather is not expected at this time. Quigley && .MKX WATCHES/WARNINGS/ADVISORIES... WI...Beach Hazards Statement...WIZ066-WIZ071-WIZ072 until 10 AM Monday. LM...Small Craft Advisory...LMZ644 until 7 AM Monday. Small Craft Advisory...LMZ645-LMZ646 until 10 AM Monday. && $$ 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