An approaching low pressure area and warm front resulted in a large area of thunderstorms moving across southern WI. A microburst resulted in tree damage at the entrance of a subdivision east of Trevor.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MKX wrote it up.
An approaching low pressure area and warm front resulted in a large area of thunderstorms moving across southern WI. A microburst resulted in tree damage at the entrance of a subdivision east of Trevor.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Milwaukee, WI wrote its last area forecast discussion before the first event at Aug 20, 8:55 AM CST, 3 hours 15 minutes earlier.
Area Forecast Discussion National Weather Service Milwaukee/Sullivan WI 955 AM CDT Sat Aug 20 2022 .UPDATE... (Issued 955 AM CDT Sat Aug 20 2022) We are already starting to see showers increase in coverage this morning across south-central Wisconsin, with a few rumbles of thunder. As of this morning, the cutoff low was slowly spinning across central Iowa, with a few lobes of vorticity rotating through the region as the broad upper-level low spins overhead. By around 16-18Z the RAP and HRRR have much of the area uncapped with some tall-skinny SBCAPE and bulk shear values between 10 and 20 kt (at best) to work with. Given the lack of shear think thunderstorm activity may remain a bit more isolated, as updrafts should struggle to remain organized but still cannot rule out some short-lived, pulse-type thunderstorms. Otherwise, conditions remain favorable for heavy downpours with any stronger showers or thunderstorm activity. Anderson && .SHORT TERM... (Issued 328 AM CDT Sat Aug 20 2022) Today through Sunday: Upper low centered over Iowa early this morning has sent a few rounds of showers and storms our way. The latest round should exit over Lake Michigan within the hour, though the moisture feed could keep showers over portions of Racine/Kenosha counties for a little longer. While the upper low will be weakening a bit and transitioning to an open wave today, we are already seeing signs of additional PVA resulting in scattered showers and storms over eastern IA and northern IL. CAMs, EPS, GEFS and CMC ensembles in general consensus with a steady east southeast progression of this low, traversing northern IL later this afternoon and this evening. Persistent PVA entering the area in waves will maintain the risk of scattered showers this morning, and with a little insolation, scattered showers and storms during the afternoon. EPS/GEFS probabilities of exceeding 0.5 inch of rainfall are confined to areas ahead of the track of the upper low, just scraping far southern WI. HREF probability matched mean guidance continues to show localized areas of higher QPF clipping southern WI as well. Bottom line, continued unsettled today, not an all day rain in any one location, but several opportunities for showers and a few rumbles of thunder. There is consensus for convection coverage to decrease markedly this evening and have lowered PoPs accordingly. Heading into Sunday, cyclonic flow will remain in place over the region as the upper low continues to slowly exit stage east. This will result in another shot at widely scattered showers during the day. Again, not everyone will get wet, but the risk is there and those with outdoors plans will need to keep an eye out and an umbrella handy for a few passing showers. Gagan && .LONG TERM... (Issued 328 AM CDT Sat Aug 20 2022) Sunday night through Friday: High pressure builds back into the region for the first half of the upcoming workweek. Northwest flow aloft still showing signs of sending a few quick moving waves our way. Timing continues to suggest Wednesday night and again late next week, though such details will be honed with time. Temperatures will be pleasant much of the week, near average for late August, perhaps a few degrees above average Tuesday and Wednesday. Gagan && .AVIATION... (Issued 955 AM CDT Sat Aug 20 2022) Expect showers and thunderstorms to increase in coverage this morning and afternoon, bringing a challenging ceiling and visibility forecast. Ceilings become mostly MVFR today, and as previously noted any lower visibilities will remain tied to where showers and storms track. Winds today remain light and in some spots variable as low pressure to our west slowly moves eastward. By Sunday, winds become predominately northerly, but remain light. Tonight we will need to monitor the potential for IFR conditions. There is a fairly large swath of stratus north of the cutoff low currently spinning across Iowa. Thus, as this low moves east today through early Sunday, we will need to keep an eye on this area of stratus. Also, there is the potential for some fog tonight, especially for areas that see heavy downpours today. Anderson && .MARINE... (Issued 328 AM CDT Sat Aug 20 2022) Low pressure of 29.9 inches over far northern Iowa will move to far southern Lake Michigan by early Sunday morning. Modest southerly winds will continue over the lake today, backing to northeasterly tonight over the northern and central portions of Lake Michigan. Light and variable winds are expected over far southern Lake Michigan Saturday night as the low passes over. Modest northerly winds are then expected over all the lake for Sunday into Monday. Periods of scattered showers and storms are expected today through Sunday. There is a potential for a few waterspouts over the southern half of the lake on Sunday. Quiet weather conditions are expected for the first half of the upcoming workweek. Gagan && .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
Hazardous Weather Outlook National Weather Service Milwaukee/Sullivan WI 344 AM CDT Sat Aug 20 2022 WIZ046-047-051-052-056>060-062>072-210845- Marquette-Green Lake-Fond du Lac-Sheboygan-Sauk-Columbia-Dodge- Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee- Lafayette-Green-Rock-Walworth-Racine-Kenosha- 344 AM CDT Sat Aug 20 2022 This Hazardous Weather Outlook is for portions of east central Wisconsin, south central Wisconsin and southeast Wisconsin. .DAY ONE...Today and Tonight Scattered thunderstorms are expected again today. Cloud to ground lightning, localized wind gusts to 40 mph and locally heavy rainfall are the main hazards expected. .DAYS TWO THROUGH SEVEN...Sunday through Friday An isolated thunderstorm is possible on Sunday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed. LMZ643>646-210845- Sheboygan to Port Washington WI- Port Washington to North Point Light WI- North Point Light to Wind Point WI- Wind Point WI to Winthrop Harbor IL- 344 AM CDT Sat Aug 20 2022 This Hazardous Weather Outlook is for the nearshore waters from Sheboygan Wisconsin to Winthrop Harbor Illinois. .DAY ONE...Today and Tonight Widely scattered thunderstorms are expected today. .DAYS TWO THROUGH SEVEN...Sunday through Friday Isolated thunderstorms and a few waterspouts are possible on Sunday. LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868- 870-872-874-876-878-210845- Lake Michigan Michigan City IN to St. Joseph MI 5 NM offshore to mid-line of lake.- Lake Michigan from Seul Choix Point to Rock Island Passage 5NM offshore to Mid Lake- Lake Michigan South of a line from Seul Choix Point to the Mackinac Bridge and North of a line from Charlevoix MI to South Fox Island 5NM offshore- Lake Michigan from Charlevoix to Point Betsie MI 5NM Offshore to mid lake- Lake Michigan from Point Betsie to Manistee MI 5NM offshore to Mid Lake- Lake Michigan from Rock Island Passage to Sturgeon Bay WI 5NM offshore to mid lake- Lake Michigan from Sturgeon Bay to Two Rivers WI 5NM offshore to Mid Lake- Lake Michigan from Two Rivers to Sheboygan WI 5NM offshore to Mid Lake- Lake Michigan from Sheboygan to Port Washington WI 5NM offshore to Mid Lake- Lake Michigan from Port Washington to North Point Light WI 5NM offshore to Mid Lake- Lake Michigan from North Point Light to Wind Point WI 5NM offshore to Mid Lake- Lake Michigan from Wind Point WI to Winthrop Harbor IL 5NM offshore to Mid Lake- Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5NM offshore to Mid Lake- Lake Michigan from Wilmette Harbor to Michigan City in 5NM offshore to Mid Lake- Lake Michigan from Pentwater to Manistee MI 5NM offshore to Mid Lake- Lake Michigan from Whitehall to Pentwater MI 5NM offshore to Mid Lake- Lake Michigan from Grand Haven to Whitehall MI 5NM offshore to Mid Lake- Lake Michigan from Holland to Grand Haven MI 5NM offshore to Mid Lake- Lake Michigan from South Haven to Holland MI 5NM offshore to Mid lake- Lake Michigan from St Joseph to South Haven MI 5NM offshore to Mid Lake- 344 AM CDT Sat Aug 20 2022 This Hazardous Weather Outlook is for the open waters of Lake Michigan. .DAY ONE...Today and Tonight Widely scattered thunderstorms are expected today. .DAYS TWO THROUGH SEVEN...Sunday through Friday Isolated thunderstorms and a few waterspouts are possible on Sunday. www.weather.gov/mkx
The Milwaukee radar (KMKX), 62 km away, was scanning. The volume nearest the first event began at 18:12 UTC.
1 thunderstorm wind. Local standard time, as filed.
Many tree branches down at the entrance of a subdivision.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2022Every state in 2022This day in weather historyWarnings in Wisconsin, August 2022
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1050823.