Heavy rain, gusty winds and thunderstorms will hit Bountiful and the Wasatch Front starting Wednesday, Oct. 21, bringing a marginal flash flood risk to northern Utah by Thursday.
The National Weather Service in Salt Lake City issued an area forecast discussion warning of widespread precipitation from Wednesday morning through Friday across the state. A cut-off low pressure system moving southward off the west coast is drawing moisture of tropical origins northward into Utah, according to the NWS discussion.
Bountiful's forecast calls for a high of 74 degrees Wednesday with a slight chance of thunderstorms, according to the NWS point forecast for the city. Clouds will build through the day as gusty southerly winds develop.
Thursday brings the heaviest rain
Thursday is shaping up as the storm's peak day.
The NWS expects waves of rain and thunderstorms to sweep across the state, with pockets of locally heavy rainfall. Bountiful's high drops to 73 degrees Thursday, with showers continuing into the night.
A marginal risk for flash flooding extends into northern Utah on Thursday, ABC4 Utah's Alana Brophy reported. A more widespread threat for isolated strong storms also moves into Utah ahead of a cold front, according to Brophy's forecast.
Statewide rainfall totals are projected at 0.5 to 1.5 inches in many areas, with some locations receiving 2 to 2.5 inches, according to the NWS discussion. The heaviest amounts are expected across southeastern Utah.
Flood watches as of Tuesday, Oct. 20, cover parts of southern, central and eastern Utah from Wednesday into Thursday but do not include the Salt Lake Valley, according to Hoodline. The NWS warns that heavy runoff could flood normally dry washes and slot canyons in those areas.
Friday cold snap and mountain snow
The storm's character shifts Friday, Oct. 23, as an upper-level low digs south across northern Utah. Bountiful's high drops to 55 degrees with showers likely throughout the day.
Colder air will push snow levels down to between 7,500 and 9,000 feet, according to the NWS forecast discussion. Northern mountains could pick up 3 to 6 inches of snow above 9,000 feet, with higher totals possible in the Wasatch Range and Uinta Mountains.
Drier weekend ahead
The storm system is expected to exit to the north and east by Saturday, Oct. 24. Weekend highs in northern Utah will settle into the 50s and low 60s.
The NWS noted that forecast confidence for the weekend remains low, with a chance a lingering low-pressure system could keep scattered showers east of Interstate 15.
Residents can monitor conditions through the NWS and sign up for flood alerts through Utah's emergency preparedness site.
