Elevated lake levels on Lake Michigan caused some isolated flooded areas near the lake on an ongoing basis.
Every event with a place to put it. Tap one for its entry below.
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 GRB wrote it up.
Elevated lake levels on Lake Michigan caused some isolated flooded areas near the lake on an ongoing basis.
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 Green Bay, WI wrote its last area forecast discussion before the first event at Aug 31, 9:27 PM CST, 2 hours 33 minutes earlier.
Area Forecast Discussion National Weather Service Green Bay WI 1027 PM CDT Mon Aug 31 2020 Updated aviation portion for 06Z TAF issuance and new information added to update section .UPDATE... Issued at 1019 PM CDT Mon Aug 31 2020 Have lowered min temps several degrees, especially in the typical cold spots of northern WI. Will probably see a few locations dropping into the middle to upper 30s. Patchy fog is also expected, especially in the Wisconsin River Valley. && .SHORT TERM...Tonight and Tuesday Issued at 219 PM CDT Mon Aug 31 2020 A few showers will continue through this evening as a weak cold front moves across the region. All mentions of thunder have been removed as the clouds and rain kept any instability from forming over the region. Expect fairly quiet conditions to return to region behind this as clouds move off to the east and a weak ridge slides into the region. Clear skies tonight will likely allow temperatures to fall across the region, with lows likely to return to the 50s. The weak ridge will be fairly short lived, moving off to east by Tuesday afternoon and evening as a low pressure system tracks just south of the area. Although the majority of this system will track well south of the region, a few showers could touch into central to east-central WI. This will likely be overrunning precipitation associated with WAA, and fairly light in nature. Highs on Tuesday will be in the upper 60s to middle 70s. .LONG TERM...Tuesday Night Through Monday Issued at 219 PM CDT Mon Aug 31 2020 Overall, not incredibly active in the long term forecast, but there are a couple opportunities for precip. Temperatures will be above normal through Thursday, then roller coaster up and down from Friday through early next week. Tuesday night...Kept showers lingering in east- central WI (mainly east of the Fox Valley) through Wednesday evening as a system to the south of the area moves eastward. Elsewhere, mainly clear skies are expected as high pressure builds in at the sfc. Winds will remain up around 5 to 10 mph, which will keep temps from falling too far. Lows will mainly be in the 50s, with a few of the typical cool spots in the upper 40s. Wednesday and Thursday...Surface high and rising heights will keep conditions dry and quiet on Wednesday, although it may be a bit breezy with wind gusts to 20 mph during the afternoon. Plenty of sunshine will allow temps to rise into the mid to upper 70s. Medium range models are in general agreement showing a mid-level shortwave and surface cold front moving across WI on Thursday. However, there are some disagreements on the southward extent of any precip as the front comes through. Moisture is limited and Pwats are around 0.9 to 1.2 inches. Kept chance PoPs in the forecast, mainly from 12Z/Thu to 00Z/Fri, with the highest potential across the north, closest to the main dynamics. Additionally, models show virtually zero CAPE during this time, therefore kept thunder out of the forecast for now. Friday and Saturday...After the cold front passes through, temperatures will cool off, with lows Friday in the 40s to low 50s, and highs in the 60s to maybe 70 degrees. Surface high pressure will bring mainly clear skies during this time period. As the high moves east on Saturday, flow shifts to the southwest and highs return to the 70s for a day. Sunday and Monday... Another sfc front/shortwave is progged to move across WI on Sunday and possibly into Monday. It is too early to sort out any details, so stuck with a blended model solution which features chance PoPs. It is also too early to determine thunder and/or severe potential. Meanwhile, the temperatures will once again drop behind the cold frontal passage with high temps in the upper 50s and 60s early next week. && .AVIATION...for 06Z TAF Issuance Issued at 1019 PM CDT Mon Aug 31 2020 High level clouds will impact the northwest part of the forecast area overnight. Patchy fog is expected to form over the Wisconsin River Valley overnight into early Tuesday morning. Mid-level clouds will increase across the southeast part of the forecast area Tuesday afternoon, and scattered showers should impact the MTW TAF site in the late afternoon and early evening. Light west winds will become southerly and increase a bit on Tuesday. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && UPDATE.........Kieckbusch SHORT TERM.....Uhlmann LONG TERM......KLJ AVIATION.......Kieckbusch
Hazardous Weather Outlook National Weather Service Green Bay WI 224 PM CDT Mon Aug 31 2020 WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-011930- Vilas-Oneida-Forest-Florence-Northern Marinette County-Lincoln- Langlade-Menominee-Northern Oconto County-Door-Marathon-Shawano- Wood-Portage-Waupaca-Outagamie-Brown-Kewaunee-Waushara-Winnebago- Calumet-Manitowoc-Southern Marinette County- Southern Oconto County- 224 PM CDT Mon Aug 31 2020 This Hazardous Weather Outlook is for north-central and northeast Wisconsin. .DAY ONE...Tonight Increasing south winds will bring high waves and the increased risk of rip currents at Lake Michigan beaches through this evening. .DAYS TWO THROUGH SEVEN...Tuesday through Monday Thunderstorms are possible at times from late Saturday night through Monday. Organized severe weather is not anticipated at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today or tonight. LMZ521-522-541>543-011930- The Bay of Green Bay south of a line from Cedar River MI to Rock Island Passage-Lake Michigan from Washington Island to Sheboygan- 224 PM CDT Mon Aug 31 2020 This Hazardous Weather Outlook is for portions of northwest Lake Michigan and the waters of Green Bay. .DAY ONE...Tonight Increasing south winds or high waves will bring hazardous conditions for small craft through this evening. .DAYS TWO THROUGH SEVEN...Tuesday through Monday Gusty winds behind a strong cold front may bring conditions hazardous to small craft Thursday and Thursday night. Thunderstorms are possible at times Sunday and Monday. Any storms that develop could be a hazard to boaters. Uhlmann/KLJ
The national radar mosaic for the moment the first event began.
2 flood. Local standard time, as filed.
Areas around the Kewaunee Marina were often under water due to high lake levels.
North Bayshore Road and County Highway Y from Harbor Road to County Highway A are closed due to ongoing flooding from high lake levels.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2020Every state in 2020This day in weather historyWarnings in Wisconsin, September 2020
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: 908316, 908318.