MILWAUKEE — From overnight tornadoes to a record December storm, the National Weather Service (NWS) announced Tuesday the top 10 Wisconsin weather events that happened in 2021.
The 2021 Top 10 Wisconsin Weather Events story map is now live at: https://t.co/CJjbgbxmpF Take a look through at each tab to see summaries of each event (best viewed on a PC/laptop). #wiwx pic.twitter.com/GQqHA9nFkh— NWS Milwaukee (@NWSMilwaukee) January 10, 2022
January Rime Ice
Rime ice appeared across parts of Wisconsin in January that created some beautiful landscapes.
Rime ice occurs in freezing fog when cold water droplets stick to and freeze on cold objects. The needles grow longer as more water droplets adhere and freeze, according to NWS.
Rime ice and hoar frost can look similar, but they form under different atmospheric conditions, NWS says.
Hoar frost forms at night when skies are clear, under moist conditions with temperatures just above freezing and without fog. NWS says water vapor in the lower atmosphere cools and deposits onto colder surfaces which then forms ice crystals.
NWS says the 2021 Drought took over much of the state and continued to be persistent across southern Wisconsin throughout the year.
The drought began in late April in western and southern Wisconsin. The drought then intensified in July and severe and extreme conditions developed in southeast Wisconsin, NWS says.
The drought developed in northern Wisconsin during late summer and conditions persisted and became widespread during late fall and early winter months, according to NWS.
Northland July Severe Thunderstorms
NWS says a line of severe thunderstorms rolled from far northwest Wisconsin through the northern part of the state on July 26, 2021.
A low pressure system that moved into the Dakotas helped push a warm/stationary front into northern Wisconsin that day, NWS says.
The storms developed in northern Minnesota before rapidly moving southeast across Wisconsin.
Damaging winds occurred across much of northern Wisconsin and trees were down in several areas.
On the night of July 28 into the early morning hours of July 29, a line of thunderstorms produced 17 tornadoes and damaging winds in Wisconsin.
"The Storm Prediction Center issued a rarely used Severe Thunderstorm Risk Category of a Moderate Risk (4 out of 5) for a good portion of Wisconsin for the potential of widespread severe thunderstorms from late afternoon through the overnight hours," NWS said on its site.
Of the 17 tornadoes, nine were rated as EF-1 with wind speeds at 90-105 mph. The remaining eight were rated as EF-0 with winds of 75-85, NWS said.
The two strongest tornadoes went through Portage in Columbia County and the town of Concord in Jefferson County.
Active Early August
There were six consecutive days of severe weather in portions of central and southern Wisconsin in the early days of August.
NWS said these episodes of severe weather included hail, damaging winds, and a few tornadoes.
Check out the timeline of these episodes by clicking here.
Boscobel EF-3 Tornado
On Aug. 7, an EF-3 tornado created a destructive path around the town of Boscobel.
NWS said damage throughout most of its path was consistent with EF1 to EF2 rating levels. But, in the area of valley-enhanced winds several miles east of Boscobel, one pocket of EF3 damage was found.
You can view the damage track with radar imagery and data from the NWS post-event ground survey by clicking here.
Large Hail - Sept. 7
Large hail measured 2 to 4 inches fell across east-central and southern Wisconsin on Sept. 7. 2021.
"A strong mid-level wave and pocket of cold air aloft tracked across central Wisconsin during the morning hours of September 7, 2021. This led to an impressive large hail event during the morning hours," NWS said.
These storms are called supercell thunderstorms and are known for their rotating updrafts.
"Supercell thunderstorms develop in areas where strong wind shear and enough instability coincide," NWS said. "This was the case early on the morning of September 7."
October was very warm across the state in 2021! Temperatures were 5+ degrees above normal and the state saw well-below normal precipitation, NWS said.
Lake Michigan waters also saw the warmest temperatures on record for the month of October in 2021, according to NWS.
A strong storm system across the Great Lakes region brought a heavy snow to the northern half of Wisconsin on Dec. 10 and 11.
A Colorado Low brought the winter storm to Wisconsin. The northern half of the state saw most of the accumulating snow with 8 to 12 inches.
"As warmer air aloft moved into the state, across central Wisconsin many saw a wintry mix of sleet, snow, and rain," NWS said. "Further south, across southern Wisconsin most saw rain on the evening of December 10, and a few elevated thunderstorms during the early morning hours on December 11."
Record December Storm
Wisconsin had its first ever tornado watch in December and record breaking warmth.
"This strong, powerful storm system brought with it high winds across much of Wisconsin, and a few tornadoes across west-central portions of the state," NWS said.
A serial derecho moving 60 to 70 mph tracked from Kansas to Wisconsin resulted in over 400 reports of damaging wind and several tornadoes across multiple states, NWS said.
Not only did Wisconsin see severe weather, but also strong gradient winds across the region!