textproduct: Salt Lake City

KEY MESSAGES

- Cool, dry, and stable conditions will persist across Utah and southwest Wyoming today and tonight.

- A weak system traverses the Great Basin on Wednesday bringing light valley rain and high elevation snowfall to northern and central Utah.

- Starting Thursday, quiet weather looks to persist as a strong ridge of high pressure builds across the western U.S.

DISCUSSION

Utah and southwest Wyoming remain between two troughs this morning on satellite imagery, resulting in largely quiescent conditions under a dry, stable air mass. Isolated areas of fog developed early this morning given calm and clear conditions, but is unlikely to return tonight given increasing mid-level clouds ahead of the trough to our west that will limit surface cooling.

As that trough continues to close off over the Great Basin, precipitation chances will increase first over the West Desert by early Wednesday morning, shifting over northern/central Utah by late morning. Low-level flow will become more northeasterly through the day, moreso favoring measurable precipitation over the Wasatch Back and areas east rather than the Wasatch Front. Still, precipitation amounts will be minimal, with the 75th percentile (25% chance of exceedance) showing around 0.25" of rainfall near Park City/Heber City. High temperatures tomorrow will be around 5-10 degrees below normal as this system brings cooler air into the region.

Following this storm system, this cooler, yet dry air mass will stick around through the work week as largely cyclonic flow dominates the western US. As skies clear later this week, we will need to monitor valley fog chances, particularly given above- normal soil moisture across the area. Over the weekend, a steady warming trend is expected as high pressure builds, with temperatures approaching 5-10 degrees above normal by Monday. Ensemble guidance suggests our next precipitation chances won't return until at least the middle of next week.

AVIATION

KSLC...Winds will remain from the southeast before transitioning to northwesterly during the 19-21Z timeframe this afternoon, though may become light and variable at times. Expect mainly mid and high clouds through tonight, then lower clouds with CIGS near or below 7kft will arrive after 15z Wednesday as showers begin to fill in. Although conditions will likely remain VFR, there is currently a 30% chance of MVFR CIGs late Wednesday morning.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions, light winds, and mid and high clouds can be expected across the majority of the TAF sites through today and the overnight hours. Fog chances are lower tonight, with around a 15% chance of IFR-LIFR conditions at prone sites such as KLGU/KHCR. Otherwise, showers will push into northwestern Utah after 12z Wednesday, overspreading northern/central UT/southwest WY by 18z. MVFR CIGs are possible with these showers, with a 30% chance across most valleys (70% chance across higher elevation sites such as KHCR/KEVW).

SLC WATCHES/WARNINGS/ADVISORIES

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