United States

Twitter user @iamalanmckenzie took this photo of large hail covering the ground after a thunderstorm moved through east Dallas, Texas, Wednesday evening.

Millions of people from Nebraska to northern Wisconsin will be at risk for powerful thunderstorms into Thursday night.

The Twin Cities of Minneapolis and St. Paul, Minn., to Sioux Falls, S.D., and Omaha, Neb., are among the major cities which could be dealing with a travel nightmare during Thursday evening.

In addition to the flooding downpours and lightning that are a staple in most thunderstorms, some of the storms could drop golf ball- to baseball-sized hail and generate wind gusts over 60 mph.

Significant damage reports as of 5:30 p.m. MDT included golf ball-sized hail near Ludell, Kan.; 2.9 inches of rainfall in Sawyer County, Wisc.; and unconfirmed funnel clouds reported in Barron County, Wisc., and Rice County, Minn.

A couple of the strongest thunderstorms could also produce a short-lived tornado. An unconfirmed tornado was reported in Prowers County, Colo. at 4 p.m. MDT.

There were also numerous reports of downed power lines, downed trees and hail across the northern and southern Plains. 60 mph winds overturned a camper at an airport in Norton County, Kan.

The large-scale weather system that will be responsible for Thursday's severe weather triggered some rather nasty storms late Wednesday as well.

Dime- to quarter-sized hail from a storm covered the ground for a time in Alamo, N.D., while golf ball-sized hail pounded a rural part of South Dakota south of Miller.

In addition to the hail, some storms produced wind gusts as high as 70 mph.

Storms with similar impacts had already developed earlier Thursday afternoon over an area spanning southern and eastern Minnesota to northwestern Wisconsin.

A separate round of severe storms will erupt this evening and tonight from central Kansas into Nebraska, including cities such as Grand Island, Neb., and Russell, Kan.

Other strong storms ongoing farther north and east will continue well after dark as they push east toward Des Moines, Iowa, and Wausau, Wis.

Residents in the threat zone should follow weather updates throughout the evening.

Remember, even if a modest thunderstorm affects your area, lightning poses a risk to your safety. Seek shelter indoors as storms approach.

A series of potent disturbances in the upper atmosphere could mean daily trouble for those of us hanging out in the lower atmosphere into next week.

Unfortunately, more thunderstorms are expected to impact many of the same areas on Friday as the surface front will stall allowing a series of disturbances to move along it.

In addition to the risk of localized severe weather, the cumulative nature of the rainfall can lead to instances of flash and urban flooding with time through the weekend and beyond.