Heat, humidity brings enhanced risk of severe weather in Minnesota

Hot, sticky conditions are priming the atmosphere for an enhanced risk of severe weather including high winds, tornadoes, hail and heavy rainfall across the state on Tuesday, June 9, and Wednesday.

The National Weather Service's Storm Prediction Center placed western Minnesota and much of the Dakotas at Level 3 out of 5, or enhanced risk for severe weather, for Tuesday into Wednesday morning. Central Minnesota from border to border is at a Level 2, or slight risk.

This means the potential for severe wind gusts of 75-80 mph or more, embedded tornadoes, hail up to the size of golf balls and locally heavy rainfall with flash flooding possible. The highest threat is for damaging winds.

"With this event largely occurring overnight, make sure to have a way to be alerted if a warning is issued for your area, as well as have multiple ways to receive warnings," the Grand Forks weather service office stated. "Also, plan now and know where to go should a warning be issued for your area."

Generally, the storms are expected to fire up Tuesday evening. But at about noon, the weather service noted the latest trends on the satellite showed the moisture-rich air and daytime heating could mean an earlier 2 p.m. arrival of severe weather for northwestern Minnesota and northeastern North Dakota.

"This activity may linger through much of the afternoon before moving into Canada — with eventual [storm] squall line still expected to move into eastern ND from central ND later this evening bringing its own, second round of severe weather," the area forecast discussion stated.

"Very strong winds with potentially line-embedded brief tornadoes remain the main hazards with this evening severe risk."

A heat advisory was issued through 8 p.m. Tuesday along the Red River Valley and north-central Minnesota, with heat index values up to 95-100 degrees expected.

Hot temperatures and high humidity may cause heat illnesses. You should drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.

To reduce risk during outdoor work, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location. Heat stroke is an emergency.

That Level 3 risk shifts eastward for Wednesday afternoon and evening, including Grand Rapids, Brainerd, Hibbing and Duluth, while most of the rest of the state remains at a Level 2 risk level.

For Wednesday's rounds of storms, the weather service in Duluth was expecting the severe wind risk to primarily impact the Arrowhead and northern Wisconsin, while hail risk up to the size of a hen egg could impact most of the Northland.

The area facing the highest threat was south of Brainerd to Grand Rapids to Two Harbors to Hurley, Wisconsin. Portions of the I-35 corridor and inland northwestern Wisconsin could see a risk for strong EF2 or higher tornadoes.

The uncomfortable conditions will extend into Wednesday, although cloud cover, showers and storms might moderate some of the heat, the weather service noted.

Drier conditions are expected beginning Thursday through the weekend, with dew points dropping into the 40s and 50s.