Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
706 FXUS63 KMKX 302013 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 313 PM CDT Sun Jun 30 2024 .KEY MESSAGES... - River flooding and high water levels remain elevated this week. Additional rises will be possible with any heavier rainfall (late Monday night through Tuesday night). - A moderate swim risk is in effect for Lake Michigan beaches in Milwaukee, Racine, and Kenosha Counties through this evening. Winds and waves subside tonight. - Patchy fog may develop tonight, with some patches of denser fog possible exclusively in low lying areas, marshes, and river valleys. - Next chances for thunderstorms is late Monday night through Tuesday night. && .SHORT TERM... Issued 300 PM CDT Sun Jun 30 2024 Tonight and Monday: High pressure resting over the region tonight will keep skies clear and winds light and variable tonight, allowing temps to fall to around 50 degrees and potentially create some radiation fog. Very few models (mainly just the NAM Nest) show a signal for fog despite the favorable synoptic setup. Hence, forecast confidence will likely remain low until it shows signs of developing. For now, the expectation is a chance for thin / patchy fog, with a few pockets of dense fog possible, mainly in low lying areas, marshes, and river valleys. The moderate swim risk will continue until late this evening for Milwaukee, Racine, and Kenosha County beaches on Lake Michigan. Buoy data indicates that waves are beginning to trend downward, hence the high swim risk has now expired. Quiet / dry weather continues into Monday. Daytime highs in the low 70s expected, with high altitude cloud cover gradually approaching throughout the day. Sheppard && .LONG TERM... Issued 300 PM CDT Sun Jun 30 2024 Monday night through Sunday: Next active weather pattern spans from late Monday night through Tuesday night. As a trough axis in the 250mb jet digs into the northern plains, a surface pressure trough extending south of a low pressure in Manitoba will work with the departed high pressure to pull a moist gulf airmass northward, leading to an initial surge of WAA driven convection. A cold front extending south of the low will then sweep through the area, continuing the moderate to heavy rainfall and thunderstorm activity into Tuesday night. It is too early to characterize what severe weather threats this may be capable of, but for now, heavy rainfall appears to be the main concern, given that several rivers remain in flood stage from our previous round of storms. Wednesday is looking mostly quiet as the cold front moves clear of our southeastern CWA in the morning. Active weather then resumes for Thursday into the weekend as another low pressure system develops in the northern plains. Sheppard && .AVIATION... Issued 300 PM CDT Sun Jun 30 2024 Diurnal cumulus will continue to rapidly erode as the sun goes down, leaving clear skies tonight. North winds (northeast in lakeshore counties) will decelerate, with light and variable winds expected overnight underneath a high pressure system. Patchy fog may develop overnight, with the potential for some denser fog exclusively in low lying / marshy / river valley areas (KLNR and possibly KJVL). This may merit a MVFR TEMPO group in the KJVL TAF if fog shows signs of developing, but has been left as 6SM BR for now. Any fog that does develop should burn off quickly after sunrise Monday given the lack of synoptic cloud cover. Dry weather continues into Monday, with ~30 kft and some 10 kft VFR cloud ceilings gradually developing. Rain and thunder chances hold off until late Monday night. Sheppard && .MARINE... Issued 300 PM CDT Sun Jun 30 2024 Gusty north winds continue over the southern half of the lake this evening. Winds will weaken tonight into Monday and become predominately easterly (light and variable further north) as high pressure around 30.3 inches builds in from the Northern Plains. High pressure will advect east of the Lake Monday night, causing winds to become southeasterly and increase. South to southeast winds will linger into Tuesday night, before a cold front moves east across the region. Behind the cold front, southwest to west winds gradually decelerate throughout the day Wednesday. Weak high pressure passing over the lake Thursday will lead to light and variable winds. Sheppard && .MKX WATCHES/WARNINGS/ADVISORIES... WI...Beach Hazards Statement...WIZ071-WIZ072 until 3 PM Sunday. LM...Small Craft Advisory...LMZ645-LMZ646 until 3 PM Sunday. && $$ 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