After almost daily rounds of severe thunderstorms targeted portions of the northern tier of the United States at the beginning of the month, these same areas experienced a brief break from damaging storms in recent days. However, AccuWeather forecasters say a renewed threat for damaging storms will rumble to life across the northern tier of the United States early this week.
The threat for feisty thunderstorms will begin on Monday across a wide swath of the northern U.S. and the southern tier of Canada as a disturbance in the upper levels of the atmosphere swings into the area. Energy associated with this disturbance will prime the atmosphere for explosive storms, especially later in the day and overnight.
"The severe threat will begin on Monday, as a cluster of storms moves through northern Montana and North Dakota, as well as adjacent portions of Canada," AccuWeather Meteorologist Andrew Johnson-Levine said.
Storms are initially forecast to develop from Montana to southern Saskatchewan, Canada, on Monday and generally track eastward throughout the day and into the overnight. By the nighttime hours, storms are expected to reach the Dakotas and portions of Manitoba, Canada.
"Hail and damaging winds will be the main concerns," Johnson-Levine explained.
In Montana, late last week, strong winds within a severe thunderstorm set off a dust storm that led to multiple fatalities on Interstate 90.
Forecasters are concerned that the atmosphere will be primed to unleash large hail on Monday as storms track across the region. Hailstones can grow to the size of golf balls or larger in the most robust storms before plummeting to the surface.
"Hailstones this large can cause damage to roofs, dent vehicles and break windshields," Johnson-Levine cautioned.
An area that stretches from northern North Dakota to southern portions of Saskatchewan and Manitoba, Canada, will be at the greatest risk for this damaging hail.
Elsewhere on Monday, a separate cluster of damaging storms is forecast to swing through northern Minnesota.
The threat for severe weather on Tuesday will depend highly on how severe thunderstorms develop and where storms ultimately move through Monday night.
"With a surge of heat and humidity along the northern edge of the continuing heat dome, severe storms are likely once again on Tuesday," Johnson-Levin explained.
Forecasters have pinpointed an area that stretches from Minnesota, Wisconsin and Michigan north into southeastern Manitoba and southern Ontario for severe thunderstorms on Tuesday. In the westernmost portion of the area of concern, thunderstorms are likely to arrive early Tuesday after trekking across the Dakotas and portions of Manitoba Monday night.
"The highest likelihood of severe weather will be where the most moisture is found," Johnson-Levine explained. "To the south, scorching heat will stifle any chance of a thunderstorm, while toward the north, the heat necessary for thunderstorms may not be present. Where the ingredients best line up, numerous intense storms will be possible."
Where storms do roar to life on Tuesday and Tuesday night, a myriad of concerns exist, including torrential rainfall, hail and damaging wind gusts. Forecasters say thunderstorms will be able to produce wind gusts on the order of 65-75 mph with an AccuWeather Local StormMax&trade of 90 mph.
Areas at risk for potent storms on Tuesday include cities like Thunder Bay, Ontario; Duluth, Minn. and Marquette, Mich..
By midweek, AccuWeather forecasters say the threat for drenching thunderstorms will shift away from the North Central states and push into portions of the Great Lakes and Northeast.
While any heavy rainfall in these regions may lead to flash flooding concerns from midweek on, precipitation is sorely needed as portions of the area work to stave off abnormal dryness and drought concerns.
