Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
663 FXUS63 KMKX 171516 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 1016 AM CDT Sat Aug 17 2024 .KEY MESSAGES... - Scattered showers and thunderstorms this afternoon with more coverage toward the lakeshore areas. These storms may produce localized heavy rain near Lake Michigan. - Breezy northerly winds will bring a high swim risk to lakeshore counties Sunday afternoon and evening. - High pressure will return early next week and bring another period of drier weather. && .UPDATE... Issued 1016 AM CDT Sat Aug 17 2024 Forecast remains on track this morning, with occasionally breaking low clouds and slowly rising temperatures expected through the day. During the afternoon hours, as a shortwave impulse propagates southeastward, scattered showers and isolated thunderstorms will develop. These are not expected to be strong, but localized heavy rain near Lake Michigan is possible. CAPE profiles indicate only a marginal potential for ice crystallization within showers and therefore marginal lightning production on most models, although the NAM indicates a more widespread thunder potential with its parcel EL well above the negative 10 degree C layer. With northwesterly flow and temperatures in the low to mid 70s, leaning toward a more isolated thunder threat away from the core of the shortwave (near the lakeshore from Sheboygan through Milwaukee Counties). MH && .SHORT TERM... Issued 356 AM CDT Sat Aug 17 2024 Today through Sunday: Low pressure spinning over northern Lake Michigan this morning will gradually slide across Lake Huron tonight. A shortwave trough swinging through WI today, aided by a compact jet streak, will help to kick off some showers and thunderstorms in southern WI this afternoon into the early evening. Expect the highest coverage to be over east central and southeast WI, with more widely scattered coverage inland. The higher concentration of storms in the east is due to being closer to the low with steeper mid level lapse rates and a little more instability than inland. Severe storms are not expected due to weaker CAPE and shear than yesterday. With more clouds anticipated than what occurred yesterday, expect high temps to be a couple of degrees lower, with a high around 80. Winds will turn around to the north this afternoon but remain fairly light. The upper low will be exiting the upper great lakes Sunday, but not without one last gasp of a shortwave rotating down Lake Michigan. This will cause an acceleration of winds and some scattered showers and perhaps a few thunderstorms near the Lake Michigan shoreline in the afternoon. Waves building to the 3 to 4 foot range will lead to a high swim risk for the afternoon and evening. Cronce && .LONG TERM... Issued 356 AM CDT Sat Aug 17 2024 Monday through Friday: High pressure will set up over the upper Great Lakes early next week as a strong and warm upper high sits over the Texas Panhandle. Overall, southern WI will be dry, slightly cooler and less humid from Monday through Thursday. There is a small chance that a few showers could develop in the afternoons as weak ripples in the upper flow track across the edge of the upper ridge from MN to WI. The better chance of that occurring could hold off until Friday as the ridge temporarily flattens due to an approaching wave from northwest Canada. Cronce && .AVIATION... Issued 1016 AM CDT Sat Aug 17 2024 Cloud bases around 1500 ft dominate across the region this morning, and are expected to slowly rise to MVFR and even VFR in some areas through the early afternoon hours. Some breaks in the clouds are expected, although these breaks are generally expected to be only an hour or two at a time. Scattered shower and storm development is still expected this afternoon, primarily along Lake Michigan terminals, although isolated storms are still expected through western terminals as well. MH && .MARINE... Issued 356 AM CDT Sat Aug 17 2024 Winds will becoming northerly this afternoon with a slight increase. Look for more gusty winds of 15 to 25 kt by Sunday afternoon, which will help build higher waves in the nearshore. A Small Craft Advisory will likely be needed. Cronce && .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