Storms move out of Milwaukee, southern Wisconsin counties; Janesville begins to assess tornado damage

Severe weather hit southern Wisconsin Saturday with at least one confirmed tornado spotted near Janesville. Follow along for live coverage of the storm:

Social media posts show signs of destruction in Wisconsin communities

The extent of the damage caused by Saturday evening's storms is yet to be determined. There were multiple reports of tornado sightings across southern Wisconsin, including in Janesville, near Watertown and over Marshall, according to the National Weather Service.

Posts to social media showed glimpses of the damage wrought by the storms.

City of Janesville reports a tornado touched down, causing 'considerable damage'

In a post on its website, the City of Janesville said a tornado touched down on the city's south side, causing "considerable damage to structures and infrastructure."

"First responders are currently on the scene, and the City has activated its Emergency Operations Center to mobilize additional resources," the post said.

The city asked residents to stay away from the south side of the city, because of the hazard posed by downed trees and power lines. Residents were also asked to avoid driving through standing water.

For questions, residents were asked to contact the city at 608-373-6025.

More than 30,000 customers without power following storms, tornado sightings

More than 12,000 We Energies customers - mostly in southeastern Wisconsin -- are without power as of 10 p.m. Saturday, following storms that swept through the area and prompted tornado watches and even warnings in some counties.

Alliant Energy reported roughly 20,000 customers affected by outages in its service area, which covers parts of Wisconsin and Iowa. The Alliant Energy outages were concentrated mostly in southern Wisconsin, including in and around Janesville, where a tornado sighting was reported Saturday evening. Several areas in Walworth County, including around Walworth and Williams Bay, also reported significant outages.

Janesville likely sustained 'significant damage' to its south side from reported tornado

Emergency responders are assessing the extent of damage in Janesville, where a tornado was spotted Saturday evening, said Mark Elland, shift supervisor at the Rock County Communications Center.

"By what we’re hearing, we probably have significant tornado damage to the south side of Janesville," Elland told the Milwaukee Journal Sentinel in a brief interview around 9:30 p.m.

The county's 911 center has been getting calls reporting everything from downed trees and power lines to flooded roads and damage to homes, Elland said.

Tornado warnings in effect for parts of southern Wisconsin have expired, tornado spotted near Janesville

A tornado warning was in effect in several parts of southern Wisconsin Saturday evening after tornado sightings near Watertown, Janesville and other cities, while other parts of southern Wisconsin remain under a tornado watch until 10 p.m., according to the National Weather Service.

The tornado warnings have since expired.

A tornado warning was issued for southeastern Kenosha County until 9:30 p.m. Saturday, according to the National Weather Service.

Earlier in the evening, other tornado warnings were issued for parts of Dane, Dodge, Green, Jefferson, Rock and Walworth counties, according to NWS. Those warnings have since expired.

Some of the warnings were issued after tornado sightings, including near Watertown, located about halfway between Madison and Milwaukee, around 7:35 p.m. Saturday, according to a NWS bulletin.

Another tornado sighting occurred just south of Janesville at 7:52 p.m.

"A confirmed large and extremely dangerous tornado was located over Janesville, moving east at 40 mph," the NWS said.

The National Weather Service advised people in places under a tornado warning to take cover.

A bulletin issued by the National Weather Service Saturday also said a tornado was spotted over Marshall around 7:15 p.m.

Tornado watch in effect until 10 p.m. across southern Wisconsin

The tornado watch was in effect until 10 p.m. across southern Wisconsin, including in the following counties: Columbia, Dane, Dodge, Green, Iowa, Jefferson, Kenosha, Lafayette, Milwaukee, Ozaukee, Racine, Rock, Sauk, Walworth, Washington and Waukesha, according to the National Weather Service.

The tornado watch has since expired.

A tornado watch is less serious than a tornado warning. A watch is issued when weather conditions favor thunderstorms producing tornado conditions in or near the "watch" area, according to the National Weather Service.

The National Weather Service noted that in addition to the possibility of tornadoes, southern Wisconsin could see damaging wind gusts and large hail.

Flash flood warnings in effect until 10:45 p.m. in Columbia, Dane, Dodge and Jefferson counties

Several counties in southern Wisconsin were also under flash flood warnings until 10:45 p.m. Saturday, including parts of Columbia, Dane, Dodge and Jefferson counties. Rock County was under a flash flood warning until 11 p.m., and Sauk County was under one until 9:45 p.m., according to the NWS bulletins issued around 8 p.m.

Dave Matthews Band concert at Alpine Valley postponed until later date

Saturday's storms took place on a very busy day for music, with several outdoor concerts planned Saturday in Milwaukee and the area, including Summerfest concerts, the second installment of the Tacos and Tequila Festival at Franklin Field, and a Dave Matthews Band concert at Alpine Valley Music Theatre in East Troy.

Alpine Valley Music Theatre posted on social media Saturday evening that the Dave Matthews Band concert was being postponed until a later date. The venue had previously posted on Facebook that it was evacuating the venue and asking people to seek shelter in their vehicles.

Meanwhile several shows at Summerfest were suspended around 7:45 due to the weather.

Anime, the opener of R&B superstar SZA, paused its show at Summerfest around 8:20 p.m. Saturday due to the weather.

Wisconsin weather radar

Wisconsin weather warnings

Reporters Jessica Rodriguez, Piet Levy and Chris Foran contributed to this story.

This article originally appeared on Milwaukee Journal Sentinel: Storms move out of Wisconsin, counties take stock of tornado damage