A low pressure system that moved from the Plains, across Illinois, to the Ohio Valley brought two periods of heavy precipitation and strong northeast winds to the area. The historic late season winter storm pummeled northeast and north-central Wisconsin from the evening of April 13th through the afternoon of April 15th.
Every event with a place to put it; 33 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.
A low pressure system that moved from the Plains, across Illinois, to the Ohio Valley brought two periods of heavy precipitation and strong northeast winds to the area. The historic late season winter storm pummeled northeast and north-central Wisconsin from the evening of April 13th through the afternoon of April 15th. The storm brought blizzard or near-blizzard conditions to much of the area and made roads impassable from time-to-time. Winds of 35 to 50 mph caused sporadic power outages and created waves of 10 to 16 feet on Lake Michigan. The persistent northeast wind caused shoreline erosion along the western shores of the lake.
New snowfall records were set at many locations as a large area of 15 to 30 inches of snow fell and winds gusted over 45 mph. Some of the highest recorded snowfall totals included, 31.6 inches near Carlsville (Door Co.), 30.6 inches in Tigerton (Shawano Co.), 30.5 inches near Stiles (Oconto Co.), 28.4 inches in Waupaca (Waupaca Co.), 27.5 inches in Peshtigo (Marinette Co.), and 25.5 inches in Suamico (Brown Co.). The strongest recorded wind speeds included 52 mph near Plover (Portage Co.), 51 mph at Marshfield (Wood Co.) and Green Bay (Brown Co.), and 50 mph near Marinette (Marinette Co.) and near Rose Lawn (Shawano Co.).
The heavy weight of the snow caused several structures to collapse or partially collapse, mainly across east-central Wisconsin. Several barn roofs collapsed in Kewaunee County, killing at least 17 cows, and parts of several barn roofs collapsed in Shawano County, resulting in the death of at least 2 cows. A barn roof collapsed near Oconto Falls (Oconto Co.) and another collapsed near New London (Waupaca Co.) killing at least 4 cows. Roofs collapsed, or partially collapsed, on at least 5 buildings in Outagamie County, including a barn in the town of Freedom where 30 cows were injured or killed. The roof of the main arena at a horse therapy center near Neenah (Wnnnebago Co.) partially collapsed. In Brown County, at least 15 businesses, including a motel and a barn, had some sort of roof collapse. Four people were trapped when a barn roof collapsed in Denmark (Brown Co.).
Snowfall totals were the highest ever recorded for an April storm in Green Bay, Appleton, Wausau and Rhinelander. This was the largest snowstorm on record in Appleton (21.2 inches), the second largest snowstorm on record in Green Bay (24.2 inches) and Wausau (20.7 inches), and the third largest snowstorm on record in Rhinelander (18.2 inches).
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 13, 5:02 AM CST, 2 hours 58 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Green Bay WI 602 AM CDT Fri Apr 13 2018 Forecast discussion for routine morning forecast issuance .SYNOPSIS... Issued at 558 AM CDT Fri Apr 13 2018 An intense spring cyclone will produce strong winds and widespread wintry weather across the area through the weekend. The westerlies flowing into western North America are split, but merge back together in a strong confluent zone over the southeast Canada. A strong upper trough embedded in the southern stream will pull out into the Plains today, then slow as it slowly tracks toward the Great Lakes region during the weekend. The initial cyclone supported by the trough will occlude over southwest Iowa tonight. That will be followed by the intensification of a secondary low near the triple point by Sunday morning. Meanwhile, an anticyclone building beneath the strong confluent zone near James Bay is expected to strengthen to AOA 1045 mb. This overall scenario hasn't changed much since yesterday. But the critical factor remains low-level temperatures, which will determine precipitation type. Those are still near critical thresholds for much of the period, so pinpointing forecast specifics remains difficult. The big picture is clear. We're heading for a very windy period with widespread significant precipitation, much of it wintry. Well below normal temperatures are expected into next week, then some moderation should occur. && .SHORT TERM...Today...Tonight...and Saturday Issued at 558 AM CDT Fri Apr 13 2018 As mentioned in the previous interim AFD, decided to stick with a watch for this forecast issuance. However, expanded it across the NW part of the forecast area for the second phase of the system. Also adjusted the end time everywhere to 05Z Monday to fit in better with surrounding offices. This still looks like a 2 round event. It's possible the first round late today and tonight can be handled with just an advisory. But low-level (and especially surface) temperatures are critical for precipitation type. The NAM and ECMWF were colder than the GFS. The former suggest considerable sleet and freezing rain, while the latter would keep a cold rain going across east-central Wisconsin much of the night. Built the temperature grids with more weight from the colder models due to the impressive feed of cold dry air coming out of the James Bay high, but hedged a little toward the warmer GFS. If surface temperatures fall more than a degree or two below what's in the forecast now, we could have a serious icing situation from central through northeast Wisconsin, especially given the strong winds. That's why sticking with the watch seemed prudent. It still looks like there will be a lull in the precipitation much of the day Saturday, with more significant bands of precipitation moving back in from the southwest late. Structured PoPs and QPF as such. The second round of precipitation will likely be warning criteria snow/wind for most of the area Saturday night into Sunday evening. Although snow and sleet should be the dominant precipitation types, freezing drizzle or light freezing rain will be possible at times when the mid-level moisture gets stripped out by a large dry slot rotating around the upper trough/low. Snow totals over east-central Wisconsin will be held down somewhat by the dry slot. But given the strong winds, the impacts from the latter part of the system seem much more consistent with needing a warning than an advisory. .LONG TERM...Saturday Night Through Thursday Issued at 558 AM CDT Fri Apr 13 2018 The main concern in the long term is the upcoming winter storm that will continue to impact the forecast area into Sunday night. Precipitation type and amounts remain uncertain at this time, but it does appear that snow should prevail at locations in the north. Uncertainty increases across central and eastern Wisconsin where ice accumulation is a concern as temperatures bottom out below freezing Saturday night and only reach highs in the upper 20s to lower 30s on Sunday. Models showed quite a bit of moisture with the system so ice and/or snow totals should be significant. A switch to all snow is expected to occur before it tapers off late Sunday afternoon into Sunday night. Confidence that significant winter weather will impact the forecast area is high enough to expand the winter storm watch across the rest of the area. Did not make any major changes to the rest of the forecast from the initial model blend. && .AVIATION...for 12Z TAF Issuance Issued at 558 AM CDT Fri Apr 13 2018 Variable/chaotic ceilings across the area will continue into today, but should settle in to MVFR and IFR as precipitation increases. The dry feed from the northeast may keep ceilings and visibilities from getting too low, even tonight. && .HYDROLOGY... Issued at 558 AM CDT Fri Apr 13 2018 Streams and rivers are likely to rise this weekend, especially over the southern portion of the forecast area where a significant rainfall and some melting of the remaining snowpack is expected. The potential for ice shoves and flooding near the mouth of the Fox River have been addressed with the Lakeshore Flood Watch. We plan to handle the watch similar to a Flash Flood Watch. (Keep it running through the event and upgrade to a warning if flooding becomes imminent or ice shoves begin to occur.). && .GRB WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from late tonight through Sunday evening for WIZ038>040-045-048>050. Winter Storm Watch from this evening through Sunday evening for WIZ013-018>022-030-031-035>037-073-074. Winter Storm Watch from Saturday afternoon through Sunday evening for WIZ005-010>012. Lakeshore Flood Watch from 1 PM CDT this afternoon through Sunday evening for WIZ022-039-074. && SYNOPSIS.......Skowronski SHORT TERM.....Skowronski LONG TERM......MG AVIATION.......Skowronski HYDROLOGY......Skowronski
Hazardous Weather Outlook National Weather Service Green Bay WI 521 AM CDT Fri Apr 13 2018 WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-141100- 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- 521 AM CDT Fri Apr 13 2018 This Hazardous Weather Outlook is for north-central and northeast Wisconsin. .DAY ONE...Today and Tonight Hazardous travel conditions are expected to develop across northern Wisconsin late today due to a wintry mix of precipitation. The hazardous conditions will spread south across most of the rest of the area overnight as rain changes to a wintry mix. Lakeshore areas from Manitowoc south may stay just warm enough to remain unaffected. Increasing northeast winds will result in hazardous conditions for high profile vehicles, and on elevated bridges and overpasses. Thunderstorms are possible across central and east-central Wisconsin today into tonight. Conditions are favorable for small hail with the storms. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Wintry precipitation and strong winds due to a major late-season winter storm will generate hazardous travel conditions during the weekend. Travel Saturday night into Sunday night may be especially difficult. Strong northeast winds may lead to ice shoves and localized flooding on the shorelines of Green Bay this weekend. Rivers and streams across central and east-central Wisconsin will be on the rise during the weekend and into early next week. .SPOTTER INFORMATION STATEMENT... The National Weather Service in Green Bay is seeking snowfall reports and reports of ice build-up due to freezing rain. Reports of any ice shoves or wind gusts over 40 mph are also appreciated. LMZ521-522-541>543-141100- The Bay of Green Bay south of a line from Cedar River MI to Rock Island Passage-Lake Michigan from Washington Island to Sheboygan- 521 AM CDT Fri Apr 13 2018 This Hazardous Weather Outlook is for portions of northwest Lake Michigan and the waters of Green Bay. .DAY ONE...Today and Tonight Northeast gales are expected from mid-day through tonight. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Northeast gales will continue into Sunday evening. Skowronski/MG
Special Weather Statement National Weather Service Green Bay WI 804 AM CDT Fri Apr 13 2018 WIZ035>038-045-048-131515- Wood-Portage-Waupaca-Outagamie-Waushara-Winnebago- 804 AM CDT Fri Apr 13 2018 ...PERIODS OF SLEET ACROSS CENTRAL WISCONSIN... National Weather Service radar shows a developing west to east band of rain, mixed at times with sleet, extending over central Wisconsin. At 750 am, an observer reported sleet covering the road in parts of New London. Radar is indicating the sleet may moderate at times over the northern portions of Wood, Portage and Waupaca Counties through 830 am. Motorists should be alert for scattered slippery spots due to the sleet accumulation. Travel with caution. TDH
The national radar mosaic for the moment the first event began.
24 winter storm, 8 blizzard, 1 lakeshore flood. Local standard time, as filed.
Persistent high waves during the storm damaged the dock for S.S. Badger ferry in Manitowoc.
The highest reported snowfall total in southern Marinette County was 27.5 inches in Peshtigo.
The highest reported snowfall totals in southern Oconto County were 30.5 inches near Stiles, 29.0 inches near Oconto, and 28.0 near Pulaski.
The highest reported snowfall totals in Door County were 31.6 inches near Carlsville, 25.0 inches near Ephraim, 24.8 inches near Baileys Harbor, 20.5 inches in Sister Bay, and 20.2 inches near Forestville.
The highest reported snowfall totals in Marathon County were 20.5 inches in Weston and Wausau, and 20.0 inches in Schofield.
The highest reported snowfall totals in Shawano County were 30.6 inches in Tigerton, 29.8 inches near Shawano, and 24.5 inches in Krakow.
The highest reported snowfall totals in Wood County were 20.2 inches in Nekoosa, 18.5 inches in Pittsville, 17.3 inches in Wisconsin Rapids, 15.8 inches near Port Edwards, and 12.0 inches in Marshfield.
The highest reported snowfall totals in Portage County were 20.7 inches in Stevens Point, 19.8 inches in Plover, 17.9 inches near Rudolph, 15.7 inches near Almond, and 14.5 inches near Junction City.
The highest reported snowfall totals in Waupaca County were 28.4 inches in Waupaca, 28.3 inches in New London, and 28.0 inches in Scandinavia.
The highest reported snowfall totals in Outagamie County were 21.2 inches in Appleton and 19.0 inches near Kimberly.
The highest reported snowfall totals in Brown County included 25.5 inches in Suamico, 24.2 inches at the National Weather Service, 23.7 inches in Ashwaubenon and 22.0 inches in Allouez. The weight of the snow and ice, from freezing rain and sleet that fell early during the storm, caused a partial or complete roof collapse at 14 businesses and 3 barns. A carport collapsed at an apartment building in Ashwaubenon, damaging 7 vehicles. Four people were trapped for a time when a barn roof collapsed in Denmark.
The highest reported snowfall total in Kewaunee County was 18.5 at Kewaunee.
The highest reported snowfall total in Waushara County was 16.7 at Wild Rose.
The highest reported snowfall totals in Winnebago County were 12.6 inches in Neenah, 12.0 inches near Omro, and 11.6 inches in Oshkosh.
The highest reported snowfall totals in Calumet County were 15.2 inches near Darboy and 11.5 inches in Chilton.
The highest reported snowfall totals in Vilas County were 19.5 inches in Lac du Flambeau and 14.8 inches near Eagle River.
The highest reported snowfall totals in Oneida County included 19.4 inches near Mc Naughton, 18.5 inches, in Hazelhurst, and 18.4 inches in Rhinelander.
The highest reported snowfall total in Forest County was 14.1 near Argonne.
The highest reported snowfall totals in Florence County were 18.0 inches near Spread Eagle and 14.1 inches in Aurora.
The highest reported snowfall total in northern Marinette County was 13.0 inches.
The highest reported snowfall totals in Lincoln County were 19.2 inches near Bradley, 18.5 inches west of Merrill, and 15.2 inches at Rice Reservoir Number 2.
The highest reported snowfall totals in Langlade County were 20.1 inches near White Lake and 17.4 inches at Summit Lake.
The highest reported snowfall totals in Manitowoc County were 11.0 inches in Two Rivers and 10.5 inches in Manitowoc.
The combination of heavy snow and blowing snow caused whiteout conditions at times during the late morning and early afternoon hours on April 15th.
The combination of heavy snow and blowing snow caused whiteout conditions at times during the late morning and early afternoon hours on April 15th.
The combination of heavy snow and blowing snow caused whiteout conditions at times during the late morning and early afternoon hours on April 15th.
The combination of heavy snow and blowing snow caused whiteout conditions at times during the late morning and early afternoon hours on April 15th.
The combination of heavy snow and blowing snow caused whiteout conditions at times during the late morning and early afternoon hours on April 15th.
Heavy snow and frequent wind gusts to around 40 mph caused whiteout conditions at times during the late morning and early afternoon hours on April 15th.
The combination of heavy snow and blowing snow caused whiteout conditions at times during the late morning and early afternoon hours on April 15th.
The combination of heavy snow and blowing snow caused whiteout conditions at times during the late morning and early afternoon hours on April 15th.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wisconsin in 2018Every state in 2018This day in weather historyWarnings in Wisconsin, April 2018
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: 751742, 750187, 750188, 750189, 750190, 750191, 750192, 750193, 750194, 750195, 750196, 750197, 750198, 750199, 750200, 750201, 750202, 750203, 750204, 750205, 750206, 750207, 750208, 750209, 750210, 750211, 750212, 750213, 750214, 750215, 750216, 750217, 750218.