textproduct: Salt Lake City

KEY MESSAGES

- Snow above 3,000 feet will spread across central and southern Utah this evening, continuing into Friday, with the majority of snow accumulation over southern Utah.

- High pressure will build in Friday, with dry and warmer conditions into early next week.

DISCUSSION

A moisture rich low pressure system is centered over southern Nevada this afternoon, with moisture and instability on the front end of the system bringing precipitation, primarily snow, into southwest Utah. Temperatures remain on the cold side behind the previous system, 10F or more below seasonal normals, with this system expected to bring a reinforcing shot of cold air.

The system will track eastward across southern Utah this evening through Friday morning, allowing snow to spread across the remainder of the southern two-thirds of the forecast area. Accumulations will steadily increase as one gets closer to the Arizona border, with southwest and south central Utah seeing the highest totals. With some totals of a foot or more expected in the mountains in less than 24 hours, this will result in some significant travel difficulties. Going suite of Winter Storm Warnings and Winter Weather Advisories cover the threat well and have made no changes with the afternoon package.

One aspect of this system that has greater uncertainty than usual is with regard to the northern extent of the precipitation and potential impacts along the Wasatch Front. Guidance today has been, if anything, trending southward with the track, keeping anything more than token accumulations away from the Salt Lake and Utah valleys. Still, given the already cold temperatures, any snow that falls will stick quickly to roads. Given that the most likely time for northern Utah snow is very near the time of the Friday morning commute, travelers should exercise caution Friday morning.

Showers will linger, primarily over the higher terrain, into the afternoon, but should shut off quickly Friday evening as high pressure moves in. The broad ridge will result in a steady warming trend by early next week, with maxes Monday currently expected to be around 10F above seasonal normals. A grazing storm system late Monday into Tuesday will curb the warming trend, with a chance the zonal flow will tap into deeper moisture, bringing the potential for valley rain and mountain snow to northern portions of the area into at least Wednesday, a type of pattern we saw a lot of at the beginning of winter.

REST OF UTAH AND SOUTHWEST WYOMING.

Widespread snow showers (generally >3000ft) will continue to overspread the southern portion of the airspace this afternoon, eventually spreading as far north as KPVU through early Friday morning. This will bring MVFR/IFR conditions for most central and southern Utah terminals through early Friday morning. North of KPVU, chances for showers drop significantly. South to southwesterly winds prevail for most regional terminals through Friday morning, transitioning northwesterly behind a weak cold front.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Winter Weather Advisory until 6 PM MST Friday for UTZ113.

Winter Weather Advisory until 6 PM MST Friday for UTZ116-118-119.

Winter Storm Warning until 6 PM MST Friday for UTZ117.

Winter Weather Advisory until 9 AM MST Friday for UTZ120-121-129- 130.

Winter Weather Advisory until 9 AM MST Friday for UTZ122-126-127.

Winter Storm Warning until 9 AM MST Friday for UTZ124-125-128.

WY...None.