Be prepared for frost — maybe snow — in northern Utah this week

It’s going to be much colder than normal on Thursday night and Friday morning.

(Francisco Kjolseth | The Salt Lake Tribune) Weather indicative of the Pacific Northwest makes a breaching whale seem more appropriate as runners endure cold wet conditions as they participate in the Salt Lake City Marathon on Saturday, April 23, 2022. Temperatures are expected to drop into the 30s on Thursday night, bringing a chance of rain mixed with snow.

Freezing temperatures are headed for northern Utah — just as high temperatures and strong winds will raise fire danger in the southern half of the state, according to the National Weather Service.

Temperatures will fall to the 60s on Thursday in Salt Lake City, then tumble again as a cold front moves in. Overnight Thursday into Friday, temperatures will drop to 34 degrees — 17 below normal — and there’s a slight chance of rain mixed with snow.

Freezing temperatures are expected across parts of northern Utah, with patchy frost across most of the Wasatch Front, Sanpete Valley, Sevier Valley and in most western valleys south to Cedar City.

The cold snap will be relatively quick though, as temperatures are expected to return to normal next week. Until then, the weather service forecasts a high of 51 on Friday, 59 on Saturday and 64 on Sunday, followed by highs of 69 on Monday and 73 on Tuesday.

(National Weather Service) A red flag warning has been issued for southern Utah.

Red flag warning issued

In southern Utah, the weather service has issued a red flag warning from noon Thursday until 9 p.m. Friday. Winds of 15-25 mph with gusts to 45 mph are expected, and humidity levels will fall to 9-12%

“Critical fire conditions are possible,” according to the weather service. “Any new fire starts could spread rapidly.”

The affected area includes St. George, Zion National Park, Cedar City, Kanab, Bryce Canyon National Park, Escalante, Big Water and Bullfrog.

Winds are expected to be strongest in the western Uinta Basin, according to the weather service, which has issued a high-wind warning for an area that includes the cities of Duchesne and Roosevelt from 9 a.m. to 9 p.m. Thursday. Winds of 30-40 mph, with gusts up to 60 mph, are in the forecast.

In St. George, temperatures in the upper 90s are expected on Thursday before falling to 81 on Friday. But temperatures will bounce back to 86 on Saturday, 91 on Sunday, 95 on Monday and 99 on Tuesday.