textproduct: Salt Lake City

SYNOPSIS

Additional storms through Monday will bring periods of heavy snow and wind to the northern mountains thanks to moisture transport streaming in from the west and northwest. Valley snow is expected at times Thursday before a warming trend into the weekend raises snow levels well above valley floors.

LONG TERM (After 12z Saturday)

Hints in guidance showing a bit more form regarding differences between previous EC/GFS ensembles for areal coverage and extent of significant precip across the northern half of the area this shift. This especially holds true regarding the Sat-Sun timeframe, the period of best potential IVT penetration into the central/northern mountains. Trends are favoring the previous EC ensemble solutions, that now look to hold the strongest weight.

High confidence for significant SWE in the central/northern mountains remains, but pulling back totals for areas south of I-80 a skosh vs previous forecast. The northern Wasatch, and especially Bear River Range, remain near status quo however. Again, it all comes down to the low amplitude ridge placement/amplification in where the greatest breadth of moisture overtopping the ridge will exist (both in residence time and extent). With a slightly more interior locale of the ridge, and slightly more amplification now dominating solutions, have shifted both breadth/residence time of the moisture plume slightly more north this forecast. In scenarios like this, 50-100 miles in latitude are significant to outcome.

Regarding the Sat-Sun period in a bigger picture...still looking at primarily an upper elevation snow impact. High confidence exists for lower valley rain within a pseudo maritime environment, and significant shadowing remains present downstream of the crests in the northern mountain valley areas where snow will fall (low end snowfall numbers and periodic frequency exists attm). Ongoing headlines reflect this thinking.

The caboose of the onshore wave train remains poised to cross the eastern Great Basin region Sunday into early Monday, and though very progressive in nature still, consensus continues to indicate enough short wave amplification to displace the ridge further south than the previous waves. As such, areal extent of precip will once again shift further south in latitude through the central mountain regions, but not as far south as the southern mountains. Although the cold advection component of the wave will be the strongest of the bunch, consensus maintains the remnant IVT within the warm sector, with rapid drying as the CAA trends cold enough for much in the way of tangible valley snowfall. Still something to watch however.

Bottom line for the long term...significant mountain snow/SWE in the northern third of the area remains a high confidence outcome (1-3" SWE). Largely dry conditions in the southern mountains/valleys remains a high confidence outcome. Northern valley snow impacts remain tied to Monday morning, but is far from a confident outcome attm.

REST OF UTAH AND SOUTHWEST WYOMING

A somewhat active TAF period exists moving forward as the first of series of disturbances is rapidly encroaching the airspace. MVFR/IFR snowfall is expected to move into the northern/central portions during the 14-20z period, followed by a more energetic wave returning MVFR/IFR cigs/vis periodically in the 22-04z window. Gusty and erratic winds are possible across northern areas with this latter wave, as are a periods of west-northwest winds in the north vs lighter southerly winds which are expected to prevail elsewhere.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Winter Weather Advisory until 8 PM MST this evening for UTZ103.

Winter Storm Warning until 11 PM MST Saturday for UTZ110>113.

Winter Weather Advisory until 11 PM MST Friday for UTZ117.

WY...None.