textproduct: Salt Lake City

KEY MESSAGES

- A mild, stable and dry pattern will continue areawide today. These conditions will support valley inversions and resultant decreases in visibility and air quality.

- Unsettled conditions are expected for central and southern Utah Friday, with light valley rain and modest mountain snow accumulations expected through Saturday.

- A cold front passage late Friday into Saturday will bring much colder conditions areawide this weekend, in addition to a period of gap winds across portions of southwest Utah Saturday, with a 30% chance of gusts in excess of 45 mph.

DISCUSSION

Another benign day is in store today across Utah and southwest Wyoming as the area remains wedged between a longwave trough across the Upper Midwest and a closed low off the coast of California. This pattern will support another day of valley inversions and resultant haze, especially across the Wasatch Front.

We're finally looking at a shift in the pattern (albeit brief, and mostly confined to the central and southern portions of Utah) beginning Friday as the aforementioned closed low moves eastward into the Baja Peninsula and phases with a secondary trough digging into the northern Plains. An area of deformation developing under this pattern will favor a SW to NE oriented precipitation band developing over central and southern Utah on Friday morning, which will bring valley rain and mountain snow chances to the area as it moves eastward into Saturday. Any precipitation this deformation band brings will remain on the lighter side given the lack of moisture across our region under this pattern, with greatest moisture availability remaining well to our south under the track of the cutoff low. 25th-75th percentile spreads still offer no confidence in total QPF accumulations, with the 25th percentile showing near zero and the 75th showing 0.10" for lower elevations and up to 0.25-0.40" for central and southern mountains. Snow levels are expected to hover around 6000-7000 feet throughout the day on Friday. Given meager water amounts, snow accumulations will also be on the lighter side, though we could see some travel impacts especially overnight Friday into Saturday morning for high elevation routes.

We'll see a mostly dry cold front associated with the northern stream trough push trough the region late Friday into Saturday morning, yielding a sharp drop in temperatures overnight. Lows on Saturday are expected to reach the teens to low 20s across the Wasatch Front and most locations across central and southern Utah, except lower Washington County which will see low temperatures in the mid-upper 30s. The Wasatch Back and southwest Wyoming are expected to dip into the single digits to teens. Given these cold temperatures, any roads that remain wet into the overnight hours may be slick by Saturday morning. This cold front will also result in gap winds developing across favored areas of Washington County Friday night into Saturday, with now a 30% chance to exceed 45 mph.

This unsettled pattern comes to a close on Sunday as the troughing pattern moves eastward and out of region, giving areas east of the Rockies the snow we've been looking for this whole season... thus, expect dry and mild conditions to redevelop areawide beginning early next week.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions expected for all regional terminals through today with generally light, terrain driven winds. There is a 20% chance VIS temporarily falls into the MVFR range around sunrise this morning at northern Utah terminals.

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SLC WATCHES/WARNINGS/ADVISORIES

UT...None. WY...None.