A cold front brought several rounds of showers and thunderstorms to central and east-central Wisconsin during the afternoon and evening hours. The storms produced gusty winds of 50 to 60 mph along with some wind damage and small hail.
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.
A cold front brought several rounds of showers and thunderstorms to central and east-central Wisconsin during the afternoon and evening hours. The storms produced gusty winds of 50 to 60 mph along with some wind damage and small hail.
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 Apr 20, 3:10 PM CST, 20 minutes earlier.
Area Forecast Discussion National Weather Service Green Bay WI 410 PM CDT Mon Apr 20 2020 Forecast discussion for routine afternoon forecast issuance .SHORT TERM...Tonight and Tuesday Issued at 410 PM CDT Mon Apr 20 2020 Main forecast concern is the potential for showers and thunderstorms through this evening. This evening through tonight...A cold front was moving across the area this afternoon producing strong gusty winds up to 50 mph and light rain showers along the front. Light rain showers, and even a mix of rain and snow showers over far north-central Wisconsin, were also trailing behind the front. Mid-level lapse rates of 7 to 8 degrees C/km were sliding across northeast Wisconsin this afternoon as 250 J/kg MUCAPE began to move into central Wisconsin. The steep lapse rates and increasing MUCAPE, in concert with the cold front, will keep thunderstorm chances in central and east-central Wisconsin through this evening. Southwest winds ahead of the front will turn west this evening then veer northwest before midnight. Although high pressure will build into the region late this evening behind the front allowing skies to clear, an upper-level jet max will remain overhead. The pressure gradient associated with this jet's northwest flow will tighten over the Upper Mississippi Valley tonight, resulting in breezy surface winds. Tuesday...As the upper-level jet max shifts over the forecast area Tuesday morning, the pressure gradient will continue to tighten. Forecast soundings indicate mixing up to 800mb could occur throughout Tuesday resulting in gusty surface winds with gusts up to 35 mph. Since the surface high pressure system will shift over the forecast area into Tuesday, very dry conditions are expected with dew points dropping to the single digits across north-central and central Wisconsin by Tuesday afternoon. Relative humidity values could drop to critical values for fire weather. However, the gusty surface winds will begin to decrease into Tuesday afternoon when the lower dew points develop. Towards the end of this forecast period, a cold front will slide into the Upper Mississippi Valley causing clouds to increase across the forecast area Tuesday evening. .LONG TERM...Tuesday Night Through Monday Issued at 410 PM CDT Mon Apr 20 2020 Northwest flow will bring a few weak systems across the area through the end of the week, then larger system possible toward/into the weekend. Temperatures through the period look to be near or below normal. Tuesday night and Wednesday...weak low pressure will track from North Dakota into northeast Iowa Wednesday afternoon. Surface warm front will lift into southwest Wisconsin ahead of the low, with light precip activity at times along and north of the boundary expected Tuesday night into Wednesday. Weak WAA, a weak shortwave and the RRQ of an upper jet will provide the main forcing, but it will be weak so only light amounts are expected. P-type will be a little tricky Tuesday night and early Wednesday morning as above freezing warm nose between 2000-5000ft could change the rain/snow to a little sleet or freezing rain. Snow accumulations look to be around a half inch or less with little to no icing. Will continue to mention the potential for some slippery roads, especially across the north, in the HWO. The light precip looks to change over to rain as the boundary layer warms up Wednesday morning. Prospects for thunder still look very low with little to no instability to work with and only marginal lapse rates. Thursday into Friday...weak high pressure builds into the western Great Lakes on Thursday, providing mainly dry weather. A weak shortwave will approach Thursday night, bringing a slight chance of a rain or snow shower. Then an upper trough and weak shortwave cross over the Great Lakes on Friday, bringing low chances for precip to the area. Should mainly be rain, but a little snow could mix in across northern WI at night. This weekend...models trending toward a large system tracking into the Great Lakes. Still time to see how models behave/trend with this system. The system does not have a lot of cold to work with, so snow potential looks iffy at this point. Could be a wind producer, with possible lakeshore flood issues on the bay if a persistent northeast wind sets up. && .AVIATION...for 18Z TAF Issuance Issued at 103 PM CDT Mon Apr 20 2020 VFR conditions with scattered MVFR cigs are expected this afternoon and evening. The scattered MVFR cigs will occur across the north-central and central TAF sites this afternoon and shift southeast this evening due to multiple rain bands moving across the area. Thunderstorms are possible this afternoon and evening across central and east-central Wisconsin. Within the strongest storms, strong gusty winds and small hail will be possible. VFR conditions will then return to the entire region with clearing skies around midnight. In addition, the gusty west/southwest surface winds, with gusts to 20 to 30 kts, will turn to the northwest this evening. The gusty winds are expected to continue through early Tuesday afternoon before gradually decreasing. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && SHORT TERM.....Hykin LONG TERM......Bersch AVIATION.......Hykin
Hazardous Weather Outlook National Weather Service Green Bay WI 317 PM CDT Mon Apr 20 2020 WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-212030- 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- 317 PM CDT Mon Apr 20 2020 This Hazardous Weather Outlook is for north-central and northeast Wisconsin. .DAY ONE...Tonight There is a chance of thunderstorms through early this evening, mainly for central and east-central Wisconsin. Gusty winds and small hail are possible in the strongest storms. .DAYS TWO THROUGH SEVEN...Tuesday through Monday Light snow is possible Tuesday night into Wednesday morning and could create a few slippery spots on roads. There is a slight chance of thunderstorms Wednesday afternoon and evening. The storms are not expected to be severe. .SPOTTER INFORMATION STATEMENT... Formal spotter activation will not be needed this evening or tonight. LMZ521-522-541>543-212030- The Bay of Green Bay south of a line from Cedar River MI to Rock Island Passage-Lake Michigan from Washington Island to Sheboygan- 317 PM CDT Mon Apr 20 2020 This Hazardous Weather Outlook is for portions of northwest Lake Michigan and the waters of Green Bay. .DAY ONE...Tonight Conditions hazardous to small craft are expected tonight. A few gale force gusts around 35 knots possible in the waters adjacent to the northern Door Peninsula late tonight into Tuesday morning. .DAYS TWO THROUGH SEVEN...Tuesday through Monday Conditions hazardous to small craft will persist into early Tuesday afternoon. Hykin/Bersch
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREEN BAY WI
306 PM CDT MON APR 20 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0248 PM NON-TSTM WND GST WISCONSIN RAPIDS 44.40N 89.84W
04/20/2020 M51.00 MPH WOOD WI ASOS
ASOS STATION KISW ALEXANDER FIELD SOUTH WOOD COUNTY
AIRPORT.
&&
KURIMSKISpecial Weather Statement National Weather Service Green Bay WI 308 PM CDT Mon Apr 20 2020 WIZ020-022-030-031-035>040-045-048>050-073-074-202315- Menominee-Door-Marathon-Shawano-Wood-Portage-Waupaca-Outagamie- Brown-Kewaunee-Waushara-Winnebago-Calumet-Manitowoc- Southern Marinette County-Southern Oconto County- 308 PM CDT Mon Apr 20 2020 ...SHOWERS COULD CAUSE LOCALLY GUSTY WINDS OVER 50 MPH THIS AFTERNOON... Showers will continue to track through the region this afternoon as a cold front sinks south. West to southwest winds are currently gusting to 35 to 40 mph, however isolated gusts over 50 mph have been reported near the showers. Some isolated thunderstorms are also possible with the stronger showers. If outdoors through early evening, be alert that wind gusts over 50 mph could occur with showers. Small hail and lightning is also possible when any thunder is heard. Should you hear thunder, go indoors. Kurimski
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREEN BAY WI
317 PM CDT MON APR 20 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0200 PM NON-TSTM WND GST WAUSAU 44.96N 89.63W
04/20/2020 M46 MPH MARATHON WI ASOS
ASOS STATION KAUW WAUSAU DOWNTOWN AIRPORT.
&&
KURIMSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREEN BAY WI
401 PM CDT MON APR 20 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0401 PM NON-TSTM WND GST ASHWAUBENON 44.46N 88.08W
04/20/2020 M54 MPH BROWN WI ASOS
AT AUSTIN STRABEL INTERNATIONAL AIRPORT.
&&
MPCPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREEN BAY WI
408 PM CDT MON APR 20 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0400 PM NON-TSTM WND GST APPLETON 44.26N 88.40W
04/20/2020 M51 MPH OUTAGAMIE WI AWOS
MEASURED AT APPLETON INTERNATIONAL AIPORT.
&&
MPCPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREEN BAY WI
416 PM CDT MON APR 20 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0410 PM NON-TSTM WND GST SHERWOOD 44.17N 88.27W
04/20/2020 M50 MPH CALUMET WI TRAINED SPOTTER
&&
KURIMSKIThe Green Bay radar (KGRB), 41 km away, was scanning. The volume nearest the first event began at 21:30 UTC.
10 thunderstorm wind, 1 hail. Local standard time, as filed.
Thunderstorm winds tipped over and damaged a large play set. The time of this event is an estimate based on radar data.
A thunderstorm wind gust of 58 mph was measured at Wausau Downtown Airport.
Thunderstorm winds downed a few trees in Plover.
Thunderstorm winds downed trees and power lines in Waupaca. The time of this event is an estimate based on radar data.
Thunderstorm winds downed trees and power lines in New London. The time of this event is an estimate based on radar data.
Quarter size hail fell in Fremont. The time of this event is an estimate based on radar data.
Thunderstorm winds snapped seven power poles north of Black Creek. The time of this event is an estimate based on radar data.
Thunderstorm winds snapped six power poles and downed wires in the town of Cicero. The time of this event is an estimate based on radar data.
Thunderstorm winds downed a tree and power lines in Nekimi. The time of this event is an estimate based on radar data.
Thunderstorm winds caused a tree to fall on a house in Howard.
Thunderstorm winds downed a spruce tree and power lines in Wrightstown.
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, April 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: 878008, 879886, 878020, 878025, 878026, 878005, 878033, 878035, 878037, 878038, 878045.