It’ll be a stormy weekend for truckers heading through parts of the Plains. Expect occasional delays due to spots of hail, high wind and torrential rainfall.
A series of cold fronts will produce waves of showers and thunderstorms across the northern and central Great Plains Friday through Sunday, August 7 through 9. Some storms may reach severe limits, slowing down drivers from time to time.
The National Weather Service (NWS) classifies a thunderstorm as severe if it produces any of the following based on radar, eyewitness reports or weather station measurements:
• Winds of at least 58 mph (50 knots).
• Hail at least 1 inch in diameter (quarter size).
• A tornado.
Most severe storm Friday will pop up across North Dakota, Minnesota and northeastern South Dakota. The National Weather Service (NWS) has placed this region under a slight risk of severe weather, meaning severe storms will be scattered throughout the target area.
This includes portions of Interstate 94 and 29 through Bismarck, Fargo and Grand Forks, North Dakota; Watertown, South Dakota; and Minneapolis-St. Paul, Minnesota.
Since severe storms won’t be widespread, drivers will hit periods of relatively quiet weather. However, the conditions may then turn stormy again at the drop of a hat, with dangerous winds, heavy hail or torrential rainfall developing suddenly. Isolated tornadoes are possible, too.
Portions of the Plains have already been slammed by severe storms this week, including a few tornadoes and many areas of destructive winds. A gust of 90 mph was measured in Harding County, South Dakota on Thursday.
The severe threat shifts southward Saturday, mainly straddling the I-90 corridor in South Dakota, extending to I-80 in Nebraska as well as northern Kansas. This includes Rapid City and Sioux City, South Dakota; in addition to North Platte and Grand Island, Nebraska. This region is also under slight risk, meaning severe storms will be scattered.
The severe threat – a slight risk again – moves back to much of Minnesota, including Minneapoli-St. Paul, as well as the I-29 corridor in North and South Dakota.
Other weekend weather
The ground is saturated in the mid-Atlantic because of Tropical Storm Isaias’ drenching rains Tuesday, followed by more showers Thursday. Additional periods of rainfall today may lead to more flash flooding along the I-81 and I-95 corridors in the Northeast and mid-Atlantic, particularly from Philadelphia and the Delmarva Peninsula to Baltimore, Washington, D.C., Richmond, Charlottesville and Norfolk. The NWS is continuing the flash flood watch through tonight for these areas.