TOOELE — A strong storm accompanied by penny- to nickel-sized hail is advancing on northwestern Tooele County. The National Weather Service is warning that travel on I-80 from Wendover to Dell could be hazardous.

A warning issued Monday by the agency is in effect until 2:30 p.m. for the storm, which is moving northeast at 20 mph and is accompanied by wind gusts up to 55 mph and heavy rain.

People in the storm's path should take shelter in a sturdy building.

Farther south in Washington and Kane counties, the National Weather Service has issued a flash flood warning, particularly for Zion National Park, that is in effect until 5:45 p.m. Monday.

Heavy thunderstorms are expected to cause flash flooding across the east fork of the Virgin River, as well as numerous slot canyons in and around Zion National Park, including The Narrows.

Those conditions are being duplicated in Wayne County at Sulphur Creek in Capitol Reef National Park. The heavy rain led to the warning that is in effect until 4 p.m.