A severe thunderstorm watch is set to remain in effect until 10 p.m. Friday for Albany, Laramie, Platte and Goshen Counties.

The watch issued by the National Weather Service lists potential threats including hail the size of tennis balls, isolated wind gusts up to 70 mph, possible tornadoes and of course torrential rainfall.

The greatest change of severe thunderstorms is in the vicinity of the I-80 corridor between Cheyenne and Kimball, Neb.

Four million people could be exposed to the storm, as well as 1,332 schools and 66 hospitals. The watch covers four Wyoming counties as well as 14 Colorado counties, including the Denver metro area.