Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
Issued by NWS Milwaukee/Sullivan, WI
450 FXUS63 KMKX 280901 AFDMKX Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 401 AM CDT Fri Jun 28 2024 .KEY MESSAGES... - Multiple rounds of showers and thunderstorms today and tonight. The greater potential for thunderstorms will be later this afternoon and overnight with a marginal (1 out of 5) risk for strong to severe thunderstorms. - River flooding and high water levels remain elevated this week and into this weekend. Additional rises will be possible with any heavier rainfall. - Dangerous swim conditions on Lake Michigan will develop along southeast WI beaches later this morning and continue through this evening with the high swim risk for Sheboygan and Ozaukee Counties` beaches.&& .SHORT TERM... Issued 357 AM CDT Fri Jun 28 2024 Today through Saturday: A mid-level impulse paired with the nose of an ongoing LLJ and low- level WAA continues to maintain widespread showers activity across IA/southern MN. Current radar imagery and obs shows the edge of this activity is clipping southwestern WI and expect it to spread eastward through the morning, especially as it merges with the upstream activity ongoing across the eastern Dakotas/western MN. However, the instability axis with MUCAPE around 500-1000 J/kg remains west of the Mississippi River and thunderstorm potential remains low as showers work their way into the area through the morning. While expecting increased shower chances (50-70%) through much of the morning, will gradually see coverage diminish through late morning as the LLJ weakens and mid-level impulse slides east. So may see a brief lull in showers this afternoon before the next mid-level impulse pushes into the region later this afternoon and evening. With the late afternoon and evening round of showers, expect a better potential to see thunderstorms, especially if the morning rounds clear out quicker than current forecast/model trends. If so this will allow instability to build a bit more across southern WI, but the better axis will remain further west closer to the cold front and the main upper-level trough. While the 00z-06z CAMs prog convection redeveloping this afternoon, it looks to remain offset from the more favorable dynamics to see stronger storms, but still cannot rule out seeing a stray strong storm or two this afternoon and evening. Then as the cold front pushes into the area overnight could see some additional storm development, but with the overnight timing and worked over environment, it may not amount to much. Nevertheless, will keep an eye on how things evolve through the day. Additionally with the multiple rounds of showers and storms impacting areas that have received heavy rainfall over the past week, cannot rule out seeing additional rises on area rivers. This may maintain river flooding and/or push a few basins above bankfull or flood. However, widespread heavy rainfall is not anticipated, but cannot rule out a few localized pockets of heavy rainfall today and tonight. In addition to the shower and thunderstorm potential, expect hazardous beach conditions to develop this morning and continue through this evening as onshore winds and waves pick up ahead of the approaching cold front. Sheboygan and Ozaukee county beaches have the greatest potential/high swim risk with life threatening rip currents, but Milwaukee and Racine counties will still see dangerous conditions with a moderate swim risk. Best to avoid swimming in areas with increased swim risk along with the windward side of breakwalls, piers, and any areas where rip currents tend to form. Otherwise, the cold front pushes through the area through the day Saturday and drier conditions are expected. Wagner && .LONG TERM... Issued 357 AM CDT Fri Jun 28 2024 Saturday night through Thursday: Upper-level ridging and surface high pressure builds across the area for Sunday and Monday. Will see another cooler stretch for the start of next week with highs in the 70s and nightly lows in the 50s and maybe even upper 40s. Then another system is progged to work its way across the region Tuesday and Wednesday. This will bring a return of southerly flow advecting warmer temps and higher dewpoints into southern WI. This midweek system will bring another shot at showers and thunderstorms paired with a series of mid-level impulses and this active pattern looks to continue into the end of next week as well. Wagner && .AVIATION... Issued 357 AM CDT Fri Jun 28 2024 Widespread light showers are gradually sliding east this morning and are expected to overtake southern WI through the remainder of the morning. While this activity remains light at the moment, could see ceilings and visibilities bounce between VFR and MVFR/IFR with any pockets of heavier rainfall. While cannot rule out a rumble of thunder or two, the more favorable environment for thunderstorm potential remains west of the Mississippi River through the morning. May see this morning activity dwindle through the afternoon bringing a brief lull before activity redevelops later this afternoon and evening. This round will bring a better potential for scattered thunderstorms through the evening. While chances remain low, cannot rule out a strong storm or two with this activity especially for southwestern terminal (MSN/JVL). Additional showers will be possible overnight before drier airmass pushes in through Saturday morning.Wagner && .MARINE... Issued 357 AM CDT Fri Jun 28 2024 High pressure continues to drift east early this morning. Expect southwesterly winds to gradually increase and turn more southerly through this morning as low pressure develops across the Central Plains and lifts into the Upper Midwest through this evening. With increasing winds expect small craft condition to develop for east Central WI nearshore waters today. Will also see increased potential for showers and thunderstorm across Lake Michigan through tonight. The low will gradually slide east- northeast into Ontario overnight into Saturday and will drag a cold front across the Lake for the start of the weekend. Behind the front expect winds to turn more northerly through Saturday afternoon and evening. Then high pressure begins to build across the Upper Great Lakes for Sunday bringing weaken winds into the start of next week before another storm system develops and brings stronger winds for Lake Michigan for mid-next week. Wagner && .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