Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
568 FXUS63 KMKX 280255 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 955 PM CDT Thu Jun 27 2024 .KEY MESSAGES... - Showers and scattered storms Friday into early Saturday morning, with a Marginal Risk for severe thunderstorms Friday evening into Friday night. - River flooding and high water levels will continue this week and into this weekend. - High Swim Risk late Friday morning through the evening for Lake Michigan beaches in Sheboygan and Ozaukee Counties. && .UPDATE... Issued 955 PM CDT Thu Jun 27 2024 A few high based showers and sprinkles are slowly progressing eastward across southern Wisconsin, with only trace amounts of precipitation expected tonight. More widespread showers are expected to develop in southwestern Wisconsin late tonight into early Friday morning, spreading eastward into southeastern Wisconsin by mid-morning. These showers are primarily driven by a 850 mb LLJ nosing into the region, with this jet diminishing into the early afternoon hours and cutting down on any lingering convection. Late afternoon, still possible for shortwaves to kick off a few thunderstorms ahead of an overnight cold front. A few storms could be strong to severe, especially in areas that see surface CAPE develop during the afternoon hours (primarily in far southwestern Wisconsin). Primary concerns remain gusty winds and small hail during the evening to early overnight hours Friday. MH && .SHORT TERM... Issued 245 PM CDT Thu Jun 27 2024 Tonight through Friday night: Surface high pressure centered over the western Great Lakes is resulting in absolutely great weather conditions across southern WI this afternoon. Expect inland temperatures to top out in the low to mid 70s, while an onshore easterly wind holds temperatures down in the mid to upper 60s along the lakeshore. Winds turn southerly tonight following the eastward departure of the surface high, and in advance of an eastward shifting aggregate lee pressure trough over the High Plains. Cloud cover will also be on the increase tonight as mid level impulses approach from the west. Overnight lows are expected to range from the mid 50s to near 60. A series of low amplitude mid-level impulses will track eastward across the western Great Lakes in advance of a more substantial trough tracking across the Dakotas on Friday. This will foster scattered showers across the area from late morning through much of the afternoon. However, rather poor mid-level lapse rates are expected to largely curtail the threat of thunderstorms for most of the day, with only a small (~20%) chance for a couple of embedded storms late in the day. Low-level moisture transport continues Friday night along the axis of a 40 kt southwesterly low-level jet, and beneath a corridor of modest mid-level lapse rates moving into the area. This will support more showers, with a better coverage of thunderstorms likely in advance of an approaching cold front, that will pass over southern WI into early Saturday morning. Effective layer shear will also be favorable for some more organized storms, which may become capable of producing gusty surface winds and instances of hail Friday night. The threat also exists for some locally heavy rainfall from these storms given the high PWATS up near 2" (roughly 200% of normal). The threat of storms will finally come to an end from northwest to southeast with the passage of the cold front into early Saturday morning. KJB && .LONG TERM... Issued 245 PM CDT Thu Jun 27 2024 Saturday through Thursday: A few showers and storms may linger into the late morning hours Saturday, particularly in the eastern portion of the CWA as the cold front moves off to the east. Following the end of the precipitation, a ridge and broad surface high pressure will begin to build into the area leading to clearing skies and quiet weather through the weekend. Northerly flow will lead to temperatures being on the cool side with highs in the low-to-mid 70s (cooler lakeside) on Sunday and Monday. An active pattern looks set to return Monday night into Tuesday and will persist through the remainder of the week. Southerly flow will bring moisture back into the area on Tuesday as cyclogenesis occurs across the northern Plains and Great Lakes. Though the chances for severe storms currently appear low due to lacking instability, the possibility cannot be ruled out this far out. Shower and storm chances continue through Thursday as several quick moving shortwaves propagate through a generally zonal flow pattern. Carothers && .AVIATION... Issued 955 PM CDT Thu Jun 27 2024 A few high based showers will produce trace amounts of precipitation tonight, while VFR conditions continue. VFR conditions are expected to continue into the morning hours Friday before showers with MVFR ceilings progress eastward through the area. A few showers could lead to ceilings dropping to 1900 ft. Friday evening, a few thunderstorms may develop, especially across far southern Wisconsin. Isolated strong to severe storms with gusty winds and hail remain possible during the evening to overnight hours. Light southeasterly winds will shift to southerly and increase Friday morning, with gusts of 20 to 25 kt expected. Winds will continue through the evening hours before shifting to become westerly late Friday night into Saturday morning as a cold front pushes through the region. MH && .MARINE... Issued 245 PM CDT Thu Jun 27 2024 High pressure around 30.0 inches is currently centered over northern Lake Michigan and will continue to drift east through this evening. In its wake southwesterly winds will increase late tonight through Friday. Shower and thunderstorm chances increase Friday afternoon into the evening and may linger into the morning hours on Saturday. Winds turn northerly and increase behind a backdoor front Saturday night into Sunday. Dry conditions are expected early next week before shower before the pattern turns more active with increasing shower and storm chances toward midweek. Petr && .MKX WATCHES/WARNINGS/ADVISORIES... WI...Beach Hazards Statement...WIZ052-WIZ060...10 AM Friday to 1 AM Saturday. LM...Small Craft Advisory...LMZ643-LMZ644...10 AM Friday to 1 AM Saturday. && $$ 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