Cold air remained across northern Wisconsin on the morning of February 15th with lows of -25 F to -40 F. The combination of the bitter cold and light winds created wind chills of -35 F to -45 F across central and north-central Wisconsin.
Every event with a place to put it; 4 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Cold air remained across northern Wisconsin on the morning of February 15th with lows of -25 F to -40 F. The combination of the bitter cold and light winds created wind chills of -35 F to -45 F across central and north-central Wisconsin. Several locations set record low temperatures on the morning of the 15th at Antigo (Langlade Co.), Merrill (Lincoln Co.), and Rhinelander (Oneida Co.).
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 Feb 14, 5:11 PM CST, 4 hours 49 minutes earlier.
Area Forecast Discussion National Weather Service Green Bay WI 511 PM CST Sun Feb 14 2021 Updated aviation portion for 00Z TAF issuance .SHORT TERM...Tonight and Monday Issued at 223 PM CST Sun Feb 14 2021 Mostly sunny skies prevailed across the region this afternoon. It was another cold afternoon with readings in the single digits below zero across central and north-central Wisconsin, and in the single digits above zero across northeast and east-central Wisconsin. Several locations are likely to break the record low maximum temperatures for today. Although wind chill readings have improved some this afternoon, they are expected to drop to Wind Chill Warning criteria (-35F or lower) across portions of central and north-central Wisconsin with the remainder of the area should see Wind Chill Advisory (-20F to -35F) readings later this evening through late Monday morning. Already extended the wind chill headlines earlier this morning until noon on Monday. Followed the NBM blend for minimum temperatures tonight as skies will be clear north and partly cloudy south. On Monday, low level winds are expected to turn to the north, and then northeast Monday afternoon. This scenario will bring some lake clouds to the immediate shoreline Monday afternoon along with some light snow showers or flurries. It will remain near record cold for low maximum temperatures for the date with highs highs in the single digits above zero. .LONG TERM...Monday Night Through Sunday Issued at 223 PM CST Sun Feb 14 2021 Cold temperatures will continue through midweek, but a gradual moderation in temperatures is anticipated through the week, with highs reaching the 20s by Saturday, and perhaps upper 20s to lower 30 by Sunday. Raised low temperatures a bit across the southeast two-thirds of the CWA Monday night, as cloud cover is expected to thicken. Should still see some lows of -20 F or colder in north central WI. Have ramped up the POPs/QPF for lake-effect near Lake Michigan Monday night into Tuesday, with unidirectional NE flow, strong thermal troughing over the lake and strong over-water instability. Snowfall may be enhanced by a short-wave trough moving through late Monday night. This is looking like a potential advisory event at this time, so will ramp up the messaging in the HWO. There are a few meso-models that have some fairly impressive QPF, so will need to keep a close eye on this event. Light easterly flow will continue Tuesday night into Wednesday, so will keep slight chance/chance POPs along the lakeshore for now, and monitor for potentially more significant LES. Strong low pressure is expected to pass south and east of the region late in the work week, with another weaker system impacting areas to our south on Sunday. Will stick with the model blend, which maintains a dry forecast over GRB CWA with both systems. Both systems bear watching over the upcoming week. && .AVIATION...for 00Z TAF Issuance Issued at 511 PM CST Sun Feb 14 2021 Outside of some high clouds, VFR conditions can be expected through much of this TAF issuance. Some lake effect clouds and perhaps a few lake effect snow showers will develop along Lake Michigan toward the end of this TAF issuance. The more widespread lake effect snow will be near the MTW TAF site after 00Z Tuesday as winds shift to the northeast. && .GRB WATCHES/WARNINGS/ADVISORIES... Wind Chill Advisory until noon CST Monday for WIZ012-013-020>022- 031-037>040-045-048>050-073-074. Wind Chill Warning until noon CST Monday for WIZ005-010-011-018- 019-030-035-036. && SHORT TERM.....Eckberg LONG TERM......Kieckbusch AVIATION.......Cooley
Hazardous Weather Outlook National Weather Service Green Bay WI 220 PM CST Sun Feb 14 2021 WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-152030- 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- 220 PM CST Sun Feb 14 2021 This Hazardous Weather Outlook is for north-central and northeast Wisconsin. .DAY ONE...Tonight Dangerous wind chills of 25 to 40 below zero are expected tonight into Monday morning. Wind Chill Warnings and Advisories are in effect. .DAYS TWO THROUGH SEVEN...Monday through Sunday Dangerous wind chills of 25 below to 40 below zero are expected early Monday morning. Wind chills should improve to 5 to 15 below zero Monday afternoon, then drop to 20 to 30 below zero again Monday night into Tuesday morning. Lake effect snow showers will bring accumulating snow to Manitowoc and Kewaunee counties Monday night into Tuesday. Several inches of powdery snow are possible, with the most significant accumulations occurring near Lake Michigan. Hazardous travel conditions will be likely. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed tonight. LMZ521-522-541>543-152030- The Bay of Green Bay south of a line from Cedar River MI to Rock Island Passage-Lake Michigan from Washington Island to Sheboygan- 220 PM CST Sun Feb 14 2021 This Hazardous Weather Outlook is for portions of northwest Lake Michigan and the waters of Green Bay. .DAY ONE...Tonight The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Monday through Sunday The probability for widespread hazardous weather is low. Eckberg/Kieckbusch
The national radar mosaic for the moment the first event began.
4 cold/wind chill. Local standard time, as filed.
Morning low temperatures fell to -29 to -37 degrees during the morning of February 15th, with light winds allowing wind chills to fall to -35 to -44 degrees.
Morning low temperatures fell to -32 to -38 degrees during the morning of February 15th, with light winds allowing wind chills to fall to -35 to -44 degrees. The low temperature of -32 degrees in Merrill broke the previous record of -30 degrees, set in 1913.
Morning low temperatures fell to -23 degrees during the morning of February 15th, with light winds allowing wind chills to fall to -35 to -38 degrees.
Morning low temperatures fell to -18 to -19 degrees during the morning of February 15th, with light winds allowing wind chills to fall to -35 to -39 degrees.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2021Every state in 2021This day in weather historyWarnings in Wisconsin, February 2021
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: 935145, 935146, 935148, 935147.