Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
042 FXUS63 KMKX 181004 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 504 AM CDT Tue Jun 18 2024 .KEY MESSAGES... - Slight chances (15 to 20%) for scattered storms in southeast Wisconsin this morning and afternoon, then better chances for storms overnight over central Wisconsin spreading east with time tomorrow. - Heat index values will be between 95 and 100 this afternoon. Hydration and frequent breaks are advised if working outdoors. - Dangerous swim conditions are likely this morning into tonight at Lake Michigan beaches in Sheboygan and Ozaukee Counties. && .SHORT TERM... Issued 459 AM CDT Tue Jun 18 2024 Today through Wednesday: This morning, a week wave over the southern end of Lake Michigan is expected to bring some low clouds to southeastern WI, along with slight chances for rain (~15%). Any rain that happens is expected to be widely scattered. Skies should clear mid morning and the heat should build, with highs in the low 90s, amid dew points in the low 70s. Resulting heat indices will be between 95 and 100 this afternoon. In addition to the heat, southerly winds will gust between 25 and 30 mph. At local beaches in Sheboygan and Ozaukee counties, this will drive a High Swim Risk from high waves and dangerous rip currents this morning into tonight. A Moderate Swim Risk will exist in Milwaukee and Racine Counties. Even with the high heat outside, swimming is not advised. Overnight, the large ridge over the eastern United States will lean more latitudinally, allowing for a cold front to make an approach at Wisconsin from the northwest before washing out. This cold front will drag showers and storms over central WI overnight. Through the day on Wednesday, the cold front will become more of a southwest to northeast oriented stationary front from Iowa into lower Michigan. Convergence along this baroclinic zone will drive on and off scattered shower and storm chances through Wednesday into Thursday. Heat will still linger south of the baroclinic zone on Wednesday, and much of southern WI will see highs in the upper 80s to low 90s again. CMiller && .LONG TERM... Issued 448 AM CDT Tue Jun 18 2024 Wednesday night through Monday: Lee troughing over the front range of the Colorado Rockies will allow for an increase in southerly flow over the plains Wednesday night into Thursday morning. Sfc WAA will allow moisture to surge back north and the stationary front should lift north as a warm front. Through the day on Thursday, sfc flow along the sfc trough/warm front will allow for east flow off of the lake, driving a lake modified air mass inland. As a result, much of southern WI should see a break from the heat, although conditions will still remain humid with dewpoints remaining in the mid to upper 60s. Weak scattered shower and storm activity may occur along the warm front as well. The WAA will bring another surge of warmth north for Friday and Saturday with daytime highs on both days in the upper 80s. Relief may not finally come until a cold front comes through Saturday night. The NBM paints great PoPs at 70%, suggesting a line of showers and storms along with the front Saturday night. Temperatures then cool for Sunday and Monday. CMiller && .AVIATION... Issued 429 AM CDT Tue Jun 18 2024 Some low MVFR to low VFR ceilings are expected to spread into southeast Wisconsin this morning with an area of light scattered showers. These showers should largely miss TAF sites in southeast Wisconsin. These ceilings should clear and FEW250 to SCT250 is expected for much of southern WI during the late morning and into the afternoon. There are low chances for pop-up thunderstorms in the afternoon, but confidence in occurrence is low. Winds will be elevated today out of the south-southwest, with gusts from 20 to 25kts. CMiller && .MARINE... Issued 421 AM CDT Tue Jun 18 2024 Modest southerly winds will prevail through the rest of this morning. Low pressure around 29.5 inches lifting from the northern Plains into northwestern Ontario today will then produce gusty southerly winds during the post dawn hours this morning and will continue into tonight. Locally, this will cause small craft advisory conditions. Winds will then gradually ease early Wednesday morning, and lighter southwesterly winds are then expected through Wednesday as the low continues to lift into the Hudson Bay. A cold front will slowly push southward across the lake Wednesday night into Thursday, shifting winds northeasterly. CMiller && .MKX WATCHES/WARNINGS/ADVISORIES... WI...Beach Hazards Statement...WIZ052-WIZ060...10 AM Tuesday to 4 AM Wednesday. LM...Small Craft Advisory...LMZ643...10 AM Tuesday to 1 AM Wednesday. Small Craft Advisory...LMZ644-LMZ645-LMZ646...10 AM Tuesday to 10 PM Tuesday. && $$ 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