As Tropical Storm Hilary lumbers toward California, the National Weather Service warned that strong to severe thunderstorms are possible Sunday across southwestern Utah, bringing gusty winds and heavy rain.
The major hurricane was downgraded to a tropical storm Sunday morning but catastrophic conditions were still expected along the Baja California coast and in California on Sunday, when it’s projected to make landfall before continuing north, forecasts show.
In west-central and southwestern Utah, there’s a 15% to 35% chance of flash flooding through Monday, the weather service said, with the risk most prevalent in slot canyons, normally dry washes, and areas near recent burn scars. The areas of Nephi, Manti, Richfield and Escalante are also at risk of flooding.
Those with outdoor plans should monitor the weather and consider changing them, the weather service said.
Flash flooding is a relatively typical risk during monsoon season in Utah, but storm Hilary will carry an elevated threat through Monday morning.
On Sunday, flash flooding is “possible” in Arches, Bryce Canyon, Canyonlands and Capitol Reef national parks, as well as Glen Canyon National Recreation Area, Grand Staircase-Escalanate National Monument, Natural Bridges National Monument, Grand Gulch and San Rafael Swell, according to the weather service. Flash flooding is “probable” in Zion National Park.
On Monday, flash flooding is “probable” in all five national parks, plus Glen Canyon, Grand Staircase-Escalante and San Rafael Swell; flash flooding is “possible” in Natural Bridges and Grand Gulch, according to the weather service.
The western portion of the state is also at risk of gusty winds through Monday, the weather service advised. South winds of 30 to 40 mph are expected, with some gusts up to 60 mph, starting Monday morning until about 9 p.m. The probability of winds exceeding 58 mph is around 50%.
Because of the wind risk, the weather service said travel on Interstate 80 will be difficult for high-profile vehicles. Power outages are also possible, and people should secure outdoor objects like trampolines and garbage cans.
St. George is under flood watch through Monday night, the weather service said, with heavy rain starting Sunday night. Unpredictable weather is expected through at least Wednesday night.
In Salt Lake City, there’s a slight chance of showers on Sunday and evening thunderstorms. Unpredictable weather is expected through at least Thursday, the weather service said.