There’s a ‘major’ risk of flash flooding in Utah

Showers and thunderstorms are expected Wednesday throughout most of Utah, according to the National Weather Service, and there’s a “major” risk of flash flooding over much of the southern half of the state.

Heavy rain “capable of causing flash flooding” will be widespread over southern and central Utah, according to the weather service. The flash flood watch continues until midnight Wednesday, although rain is expected in many areas through Thursday morning.

Thunderstorms will develop between midday Wednesday across western Utah, and gradually increase through the afternoon and into the evening, the weather service advised.

Flooding dangers

Flash flood watches are in effect for the cities of St. George, Cedar City, Brian Head, Bryce Canyon City, Ivins, Milford, Springdale, Beaver, Alton and Hurricane, and also are in effect for all Utah’s national parks, monuments and recreation areas.

Flooding is “expected” at Arches, Canyonlands and Capitol Reef national parks; Grand Staircase-Escalante and Natural Bridges national monuments; Glen Canyon National Recreation Area; and Grand Gulch and San Rafael Swell recreation areas. Flash floods are “probable” at Bryce Canyon and Zion national parks.

The greatest danger of flooding is in slot canyons, areas near wildfire burn scars, and normally dry washes. Hikers are advised to avoid those areas Wednesday.

The National Weather Service also warned residents of Utah and Uintah counties that “potentially the most significant severe weather outbreak of the summer is expected” on Wednesday.

Temps expected to cool

In Salt Lake City, there’s a 70% chance of showers and thunderstorms on Wednesday afternoon, and the storms could produce small hail and gusty winds. There’s a 60% chance of more storms Wednesday night, and a 20% chance on Thursday morning.

The flood watches came a day after Salt Lake City set yet another heat record. It hit 92 degrees at 2:03 p.m. at Salt Lake International Airport on Tuesday, breaking the record for the date (Sept. 20) of 91 degrees set back in 1933.

Temperatures are expected to cool considerably — a high of 81 is forecast for Wednesday, along with 71 on Thursday, 74 on Friday, 79 on Saturday and 80 on Sunday.

In St. George, there’s a 50% chance of rain on Wednesday, falling to 30% Wednesday night before sunny skies return Thursday.

Temperatures in the mid-80s are expected there through Friday, and the forecast calls for a high of about 90 on Saturday and Sunday.