SIOUX FALLS, S.D. (KELO.com) — Following scorching temperatures to begin the week, the north-central United States will have to gear up for a different weather threat heading into midweek.
The region had a taste of severe weather to begin the week as dangerous thunderstorms buffeted portions of the region with hail and rain on Sunday. Western North Dakota took the brunt of the hail pummeling on Sunday as baseball-sized hail was reported in Adams and Hettinger counties.
After a brief reprieve from the severe threat on Monday, residents in the north-central U.S. will once again have to be alert for severe thunderstorms on Tuesday and Wednesday.
“As an area of low pressure and warm front move northward from North Dakota into southwestern Manitoba late Tuesday afternoon and into Tuesday night, severe thunderstorms will become a possibility,” AccuWeather Meteorologist Ryan Adamson said. “The highest severe probabilities will be across western North Dakota, southeastern Saskatchewan and southwestern Manitoba.”
Residents of cities like Bismarck and Minot, North Dakota, as well as the Standing Rock and Cheyenne River reservations in South Dakota, will need to remain weather-aware through Tuesday evening.
Tuesday’s storms will be rather isolated in nature, with no organized clusters or lines of storms expected to develop. However, any storms that bubble up on Tuesday will be able to pack quite a punch.
“The main threats from Tuesday’s storms will be large hail and damaging winds, with an AccuWeather Local StormMax™ of 70 mph (110 km/h),” Adamson said.
For Wednesday afternoon and evening, the threat for severe thunderstorms will shift eastward into southern Manitoba, the eastern Dakotas and northwestern Minnesota.
“A pocket of cold air in the upper atmosphere moving eastward from the Rockies, in tandem with a cold front, will cause storms to be much more widespread on Wednesday than on Tuesday,” Adamson said.
Ahead of this front, temperatures for much of the region will soar into the mid- to upper 90s F, 15-20 degrees Fahrenheit above normal for mid-June. Those spending any amount of time outdoors before storms develop in the afternoon will need to stay well hydrated to avoid heat-related illnesses such as heat exhaustion and heat stroke.
When the cold front digs into the area Wednesday afternoon, it will encounter very warm air and increasing moisture at the surface, which will provide plenty of atmospheric fuel for some explosive storms.
“Threats on Wednesday will be similar to Tuesday, but will extend over a larger area,” Adamson said. “However, local flash flooding and isolated tornadoes will be additional threats as compared to Tuesday.”
Storms that develop Wednesday afternoon may be able to congeal into damaging lines of thunderstorms, rather than individual cells. If storms on Wednesday are able to congeal, the threat for widespread wind damage will increase, as will the threat for isolated tornadoes.
A few cities under the threat for large hail, torrential downpours and damaging winds with an AccuWeather Local StormMax™ of 70 mph (110 km/h), and even an isolated tornado or two include Aberdeen, South Dakota; Fargo and Grand Forks, North Dakota; and Winnipeg, Manitoba, Canada.
Drier and cooler weather is forecast for much of the region after the cold front departs and storms wind down later Wednesday night. Many locations will have a return to seasonable conditions, with high temperatures on Thursday expected to be 15-20 degrees lower than Wednesday.
(Mary Gilbert, AccuWeather meteorologist, contributed this report.)



