Utah forecast: It’s warm, and then comes the storm
Winter Storm Warning • Heavy snowfall along the Wasatch Front, just in time for the evening commute.
Published: January 10, 2013 01:49PM
Updated: January 10, 2013 09:15AM

Call it the warm before the storm.

Northern Utah’s forecast Thursday called for daytime temperatures well above the frigid readings common for the past couple weeks with highs ranging into the mid-40s. But come late Thursday afternoon, that was to take a dramatic shift.

Driven by winds of 10-20 mph with gusts above 40 mph, a major Northwest Pacific storm system was due to arrive just in time for the evening drive home from work. Galloping in on that pale climatological horse was what forecasters warned could be a snowy hell for commuters.

The National Weather Service issued a Winter Storm Warning covering most of the state. From Logan running south through Ogden, Salt Lake City, Provo, Nephi and Escalante and extending southwest to St. George and as far as Wendover, on the Utah-Nevada border, the storm was expected to bring heavy snowfall.

The advisory was set for noon Thursday through noon Saturday. Forecasters predicted 5-10 inches of snow in valleys along the Wasatch Front and central and southern mountains, with the benches bracing for 6-12 inches and the mountains themselves 1-2 feet, and in some places even more.

Strong winds could cause drifting in mountain passes and lower visibility considerably elsewhere, too.

However, the turbulence and fresh air it brings was to have an immediate, favorable impact on the state’s air quality. Much of Utah started Thursday in the “Red,” or unhealthy air quality zone, but the Utah Division of Air Quality graded breathability for the entire state as “Green,” or healthy beginning Friday.

The trade-off? After Thursday’s near balmy temperatures, the state was to plunge into the deep freeze again Friday and through the coming weekend. Daytime highs were expected to dip 20-30 degrees Friday, compared to Thursday’s readings.

Salt Lake City, at 45 degrees Thursday, expected an overnight low of 20 ahead of Friday’s predicted high of just 25 degrees; Ogden’s forecast was for 42, 18 and 20 degrees, respectively; Provo 42, 21 and 24; Logan 37, 12 and 16; Wendover 30, 15 and 30; Duchesne 26, 8 and 15; Cedar City 41, 9 and 20; St. George 53, 27 and 41; and Moab 41, 26 and 30 degrees.

Avalanche danger, graded at “moderate” throughout the state for Thursday, was expected to rise to “considerable” Friday as heavy, new snow pack came to the mountains above Logan, Salt Lake City, Provo and Ogden.

remims@sltrib.com