872 FXUS63 KMKX 052007 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 307 PM CDT Sat Jul 5 2025 .KEY MESSAGES... - Showers and thunderstorms are expected this afternoon through tonight. A few storms could produce gusty winds and locally heavy rainfall. - Hot and muggy conditions continue with heat indices in the low to mid 90s. - Small Craft Advisory remains in effect this afternoon in all nearshore zones. - Periods of moderate swimming risk this afternoon at Sheboygan County beaches. - Poor air quality expected near Lake Michigan today. - Humidity returns Tuesday through the end of the week, with periods of showers and thunderstorms also returning. && .SHORT TERM... Issued 307 PM CDT Sat Jul 5 2025 Tonight and Sunday: Low pressure system has advanced eastward toward the Upper Peninsula of Michigan this afternoon. As the sfc low moves east so to does the upper level trough/wave bringing some PVA to Wisconsin. A sfc cold front has slowly been moving across the state today and is over central Wisconsin. More widespread lift will produce scattered to isolated showers/storms across southern Wisconsin this afternoon through tonight. The environment is unstable through the column with sfc temps in the 80s to low 90s and dewpoints in the upper 60s to low 70s. South to southeast winds have increase out ahead of the approaching cold front. From ACARS and forecast soundings there is not much shear outside of the 0-1 km layer currently or for tonight. 0-3 km shear is at its best across our northwest around 25 to 30 knots, but 20-25 kts is optimistic for the rest of southern Wisconsin. So not a great environment for organized convection through tonight. The cold front will continue to advance east and CAMs continue to show some weakening of the line as it hits eastern Wisconsin. Forecast soundings show a fairly moist column throughout, especially as the front begins to move in, but a few models do try to bring in some CIN later this evening. Which is likely what the most conservative models are latching onto. Not sure where the middle level warm air or midlevel dryness is coming from for these models to run away with. Low, mid and upper level water vapor satellite shows moisture throughout the column and doesn`t show any wing of dry air. Regardless kept rain chances up as the front moves through around 60-80%. The highest rain chances will be along the front and we are primed for rain. This scattered to isolated nature from the CAMs will be something to keep an eye on as we watch the segment of the line coming out of IA through the afternoon. With the little shear and line parallel winds, heavy rain and lightning are the major concerns with any storms through tonight. Can`t rule out some brief gusty winds, but the better chances for stronger winds will north and west of Madison where there is better shear. Flooding concerns will largely be limited to urban and small stream type of effects where urban/city environments will struggle to take rain away effectively and rises in small rivers and creaks are probable. Given the slow moving nature of the front, isolated showers and storms will be slow to make it to the far east and southeast.The chances for any stronger storms or brief gusty winds will drop off quickly after sunset as we look diurnal heating, but heavy downpours will continue to be likely. Rain will be possible through tonight and linger into tomorrow morning/early afternoon for those eastern counties. As the frontal boundary lingers, rain chances will remain, but will be low. Cooler and drier air will move in behind the front keeping highs in the upper 70s to low 80s. Dry weather is expected Sunday evening through Monday night. Patterson && .LONG TERM... Issued 307 PM CDT Sat Jul 5 2025 Monday through Saturday: Cooler more near normal temperatures are expected through the week with high in the upper 70s to mid 80s. High pressure will move through the northern Great Lakes Region and Ontario Canada Monday bringing dry weather and light winds. Heading into Tuesday the high pressure will break down over the Great Lakes Region and continue east. High pressure will build back into the northern plains and the upper level steering flow remains a bit zonal during this transition period. Multiple little waves try to move through the upper level steering flow. A few shortwaves will run over the ridge building in the west. There is uncertainty in timing and placement of these shortwaves, but guidance is maintaining consistency on a chance of rain Tuesday afternoon into Tuesday night with POPs of 30 to 40%. Winds will return to southern Tuesday and humidity will start to return so there is come decent confidence that with enough lift we could see some scattered showers. The next chance guidance highlights a better chance for rain will be Friday night (40-50%). For friday guidance is latching onto a stronger shortwave trough with an associated low pressure system, that is expected to advect out of the Plains. Will have to keep an eye on both chances for rain, but overall a more quiet forecast when compared to previous weeks. Patterson && .AVIATION... Issued 307 PM CDT Sat Jul 5 2025 VFR conditions will prevail under mostly clear skies through mid afternoon. By late this afternoon, a low pressure system will advect east out of Minnesota and bring a cold front across the state. Multiple rounds of scattered to isolated rain and thunderstorms are expected as this front moves through. The front will be slow moving so rain chances will last into the overnight hours. Far southeastern Wisconsin will see rain linger into Sunday morning. Gusty south to southeast winds have developed late this morning and will continue out ahead of the front with gusts 25-30 MPH possible. Highlighted the highest confidence for rain/storms in the TAFs. MVFR to IFR ceilings and visibilites are expected as the rain and storms move through. MVFR ceilings are likely to persist behind the passage of the cold front tonight into early Sunday morning. Patterson && .MARINE... Issued 307 PM CDT Sat Jul 5 2025 As a low pressure system advances east into the Upper Peninsula of Michigan, breezy south to southeast winds have developed across Lake Michigan with gusts of 20 to 25 kts possible. These gusty winds have caused waves to build in the nearshore bringing a moderate beach hazard to Sheboygan beaches and a Small Craft Advisory for nearshore waters. The low pressure system will continue east and drag a cold front across the lake this evening through Sunday afternoon. Showers and thunderstorms are expected along the front as it moves through. The front is very slow moving so rain chances will linger along the eastern coast into Sunday afternoon. Winds will shift to the north to northwest behind the front with northerly winds across the entire lake expected by Sunday afternoon. North winds will remain over the lake through Monday evening. High pressure will then build in over the lake bringing light and variable winds through mid week. Patterson && .MKX WATCHES/WARNINGS/ADVISORIES... WI...None. LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 8 PM 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