Twin Cities and much of Minnesota under threat for large hail, tornadoes Monday afternoon

It’s a busy day at the National Weather Service offices in Chanhassen, where meteorologist Nick Carletta has his eyes on six screens, watching for storms that could bring violent weather to the Twin Cities in the form of high winds, large hail and even tornadoes.

A large portion of Minnesota from St. Cloud south to the Iowa border is also under a high risk for severe weather that is expected to develop Monday afternoon through early evening, Carletta said.

“Keep an eye on the sky and have a trusted source to get weather information,” he said.

Around 4 p.m., the National Weather Service issued a tornado watch for a large portion of eastern and southern Minnesota that covered the Twin Cities area.

The watch is set to last until 11 p.m. and covers everything from the city of Morris, in Stevens County, all the way east to Eau Claire, into Wisconsin, and from Hinckley south into Iowa.

A tornado warning is in effect for Stearns and Wright counties. The National Weather Service said a severe thunderstorm capable of producing a tornado was located over Kimball about 20 miles south of St. Cloud and moving northeast at 45 miles per hour. Residents were also warned of possible hail the size of ping pong balls.

All the ingredients needed for dangerous and destructive weather were coming together across eastern South Dakota and expected to cross into Minnesota by the afternoon, Carletta said.

A tornado watch was in effect until 8 p.m. for western Minnesota, including cities such as Morris, St. Cloud, Willmar, Worthington and Marshall, the National Weather Service said.

“We are expecting another watch later as the threat progresses eastwards,” the Weather Service said. “The most important thing to do today is not to let your guard down. With conditional threats, storms can intensify quickly, highlighting the need for having multiple ways to receive warnings at a moment’s notice,” the Weather Service said.

While a large swath of the state could see severe weather, the best environment for tornadoes was across southern Minnesota and northern Iowa, the Weather Service said.

In the meantime, the first severe thunderstorm warning was issued for Rock, Nobles and Murray counties in southwestern Minnesota, but expired at 2:15 p.m.

A warm front colliding with a cold front has “a lot of windshear” in the environment, setting the stage for an outbreak of twisters.

“If we get a supercell, there would be the potential,” Carletta said. “Let’s cross our fingers we don’t have that.”

In anticipation of inclement weather, St. Paul Public Schools has called off after-school programs and activities. High school activities will be decided on a case-by-case basis and community education classes will be held as scheduled, the district said. Minneapolis Public Schools also canceled all after-school activities including extended learning, youth enrichment programming and athletics, the district said in an email to families.

In Minneapolis, many city facilities and services will close at 2 p.m. Monday. The city has activated its emergency operations center and will keep 311 operators on duty until 9 p.m. to take storm-related calls. Public works crews were dispatched to clean storm drains to help mitigate any flooding, the city said in a news release.

All Minneapolis Park and Recreation Board public buildings will close at 2 p.m. and all programs and activities are canceled, officials said.

The National Weather Service advised Twin Cities residents and those in Albert Lea, Rochester, Red Wing, Fairmont and Mankato to have plans in place in case they need to take shelter on Monday. Western Wisconsin and northern Iowa also are in the bull’s-eye, according to the Storm Prediction Center.

The moderate risk, or level 4 out of 5 on the severity scale, comes as AccuWeather says Monday could be one of the most active days of the severe weather season so far.

Carletta said it is unusual, but not unprecedented, to have a risk this high across Minnesota in April. Typically this elevated risk would occur in late May and into June, the peak of severe weather season locally.

Carletta said watches and warnings may come out and described them as a taco to help people know the difference.

A watch is when you have the soft shell, the meat, the lettuce and other fixings on the table and that conditions are favorable for bad weather.

A warning, he said, is when the taco is fully assembled. A warning means severe weather or a tornado is “imminent or occurring,” Carletta said.

With conditions favorable for bad storms, Minneapolis city officials urged residents to prepare: