The western two thirds of Utah is under a Hazardous Weather Outlook advisory with gusty winds, thunderstorms and rain showers, occasionally heavy, expected through the end of the week.
Those stormy conditions come with a strong cold front that also will send temperatures along the Wasatch Front sliding into more autumnal conditions. On Thursday, southern and eastern Utah also will feel the change, and precipitation poses the risk of flash flooding in slot canyons, along waterways and on mountain slopes recently denuded by wildfires.
The Salt Lake and Tooele valleys, partly sunny through Wednesday morning, are forecast for upper-80s temperatures and increasing cloud cover through the afternoon and by evening scattered showers and thunderclaps.
Windy, wet weather was to resume Thursday, with gusts up to 30 mph punctuating a plunge in temperatures into the upper-70s. More rain comes on Friday, with temperatures slipping into the mid-60s.
A similar cycle of storms and rainfall was expected the next few days in the redrocks and high deserts of Utah's Dixie. Highs in St. George, in the mid-90s Wednesday, will retreat into the low- to mid-80s Thursday and Friday.
The wind and the rain are friends to the Utah Division of Air Quality: The entire state, including the usually ozone- and particulate-compromised urban valleys of the Wasatch Front, will have "green," or healthy air quality beginning Thursday.
The Intermountain Allergy & Asthma website showed only sagebrush as being “high” on its pollen index as of Wednesday, while ragweed and mold were at “moderate” levels.