SALT LAKE CITY (ABC4) – The thunderstorm threat has been upgraded for parts of the Wasatch Front including parts of Salt Lake, Summit and Utah Counties, as well as Castle Country and the Uinta Basin.

The Storm Prediction Center upgraded the thunderstorm threat today from general to marginal for NW Utah and the northern Wasatch Front. A general thunderstorm threat extends into the rest of the state, with the exception of the extreme northwest portion of the state.

A “marginal” risk on the thunderstorm scale means there’s a chance of an isolated severe storm possible with winds gusting between 40-60 mph and hail up to 1 inch in diameter, which is about the size of a quarter. With a general thunderstorm threat, no severe storms are expected. Winds can gust up to 40 miles per hour and a storm could produce small hail. With today’s storms, microburst winds are most likely with blowing dust so secure loose objects now.

Remember, in order for a thunderstorm to be classified as severe, it needs winds equal to or exceeding 58 miles per hour and hail at or greater than 1 inch in diameter.

In addition to strong thunderstorms, in southern Utah, deeper moisture will lead to a marginal risk for excessive rainfall in parts of southwestern Utah and an increased risk for flash flooding at national parks so keep that in mind if you have any hikes planned, especially in slot canyons.

Flash flood potential for normally dry washes and slot canyons increases as a result, especially for Zion, Capitol Reef, and the Grand Staircase area, which are looking at probable flooding on Wednesday and Thursday.

Stay with the Pinpoint Weather Team as warnings evolve throughout the evening, and tomorrow as the storm and flood threat continues.