Thursday will generally start quietly across the Plains and Upper Midwest. However, forecasters say that is likely to change by late in the day and overnight.
A warm and humid air mass will be in place across the Dakotas, Nebraska, and Minnesota on Thursday. As a cold front moves eastward toward the region, showers and thunderstorms are likely to develop. With the front providing a focal point for thunderstorms, the activity is likely to continue into the overnight hours as well.
As storms initially form late on Thursday afternoon, large hail will be a hazard. It then appears that the storms will quickly develop into a line by Thursday evening. At that point, while hail will still be a risk, the main concern will become locally damaging winds. Therefore, residents in locations such as Aberdeen and Sioux Falls, South Dakota, and International Falls, Minnesota, will need to keep an eye to the sky and be prepared to seek shelter should skies darken or if thunder is heard.
“Those who are planning on traveling or spending time outdoors should use caution and have a backup plan set up in case storms put a damper on any pre-made arrangements,” Sadvary advised.
Late Thursday evening, as a disturbance moves out of Montana, one or two new areas of thunderstorms are expected to form in far eastern Montana. These storms will likely then move into western North Dakota after midnight and continue eastward into central North Dakota before beginning to weaken. The thunderstorms in this area are not expected to be severe, but they still could contain gusty winds, small hail and heavy rain.
“The greatest threats with these storms will be frequent lightning, hail, damaging wind gusts and localized flash flooding in heavy downpours, but the possibility of a few isolated tornadoes spinning cannot be ruled out,” added Sadvary.
The cold front will continue eastward on Saturday but at this point severe thunderstorms are expected to be less of a threat than on Thursday and Friday.
(AccuWeather meteorologist, contributed this report.)
