Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
082 FXUS63 KMKX 112006 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 306 PM CDT Sun Aug 11 2024 .KEY MESSAGES... - No hazardous weather expected through the first half of the week. - Outside of very low chances (<15%) of showers across southern WI on Monday, the forecast remains mostly dry until the later half of the week when the pattern becomes more active. - Chances for showers and thunderstorms (30 to 60%) from Wednesday night into this weekend. Highest chances (around 60%) for rainfall are Thursday / Thursday night. && .SHORT TERM... Issued 305 PM CDT Sun Aug 11 2024 Tonight through Monday night: No hazardous weather expected throughout this period. Dry weather is likely for the rest of today and overnight as high pressure rests overhead. An arc of showers currently over northern WI is expected to dissipate with the shutdown of daytime heating, and is not currently expected to reach us. Light westerly winds decelerate this evening, with weaker westerly flow expected to resume Monday. Mostly dry weather is expected Monday, except for a <15% chance for showers, primarily forced by a shortwave trough sliding down the ridge to our west triggering convective showers in IA / MO / IL, secondarily by a NW- SE oriented 700mb moisture plume / frontal wave aloft entering WI from the north. Both have the ability to produce rain showers nearby, but with a dry air column indicated on forecast soundings, most will erode before reaching our region or evaporate before reaching the ground (hence rain chances <15% Monday). Despite 500mb heights continuing to gradually rise as the ridge builds back into our region, partly to mostly cloudy skies result similar temps on Monday (perhaps 2 degrees warmer than today). For Monday night, dry with light and variable winds under the high pressure system. Sheppard && .LONG TERM... Issued 305 PM CDT Sun Aug 11 2024 Tuesday through Sunday: No hazardous weather expected Tuesday through Wednesday afternoon. As the upper-level ridge to our west gradually builds back into our area, quiet / dry weather and gradually increasing daytime high temps (up to the low 80s) are expected. Meanwhile, a trough in the upper air pattern progresses eastward across the northern Rockies and Plains. This trough, potentially evolving into a cutoff low, will set the stage for a more active pattern. A surface low forms ahead of the trough (over the plains) Wednesday, tracking eastward. WAA out ahead of this system is likely to lead to scattered showers and thunderstorms, with precip chances arriving Wednesday night into Thursday. Peak rain chances (around 60%) are currently from Thursday through Thursday night. Until model guidance converges on a solution, it is uncertain how long this low pressure (and associated shower / thunderstorm chances) will linger over our region before drifting east. Hence, shower / storm chances linger through the weekend. Sheppard && .AVIATION... Issued 305 PM CDT Sun Aug 11 2024 VFR conditions continue throughout the period. West winds decelerate and diurnal cumulus clear out this evening. Aside from a very small (<15%) chance of rain showers throughout the daytime hours of Monday, dry weather continues. Weaker west winds and diurnal cumulus clouds (generally 4000 ft or higher) redevelop on Monday. Sheppard && .MARINE... Issued 305 PM CDT Sun Aug 11 2024 High pressure around 30.2 inches over the mid-Mississippi River Valley will slowly meander eastward into the Great Lakes region through the first half of the week. This will bring lighter and more variable winds to Lake Michigan through midweek before turning more southerly and increasing for the second half of the week. Low pressure around 29.7 inches will develop over the Great Plains by Wednesday, tracking northeastward into Wisconsin late this week and deepening to 29.6 inches. This will lead to accelerating south to southeast winds Thursday and Friday, with shower and thunderstorm chances across the lake. Sheppard && .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