textproduct: Salt Lake City

KEY MESSAGES

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

- A cold front passing through the area Friday into Saturday will bring cooler temperatures and mix out valley inversions. Northern Utah and southwest Wyoming are expected to stay dry, though portions of central and southern Utah will see modest accumulations of valley rain and mountain snow.

- The frontal passage will also support potential for a period of gap winds across portions of southwest Utah Saturday, with roughly a 10-20% chance of gusts in excess of 45 mph.

DISCUSSION

Utah and southwest Wyoming remain under a dry and stable west to northwest flow this afternoon between a low off the California coast and a broader trough moving into the central United States. Inversions persist in prone valleys, with local decreases in air quality and visibility. This pattern will persist into Thursday.

By Friday, the California low is expected to phase with a Pacific Northwest trough, with these features eventually moving across the Desert Southwest over the weekend. The northern system looks to bring a cold front into the area from north to south late Friday into Saturday. Over northern Utah and southwest Wyoming, the frontal passage is expected to be dry, but will bring cold enough air to give the valleys a high chance to mix out valley inversions. Ensemble guidance tends to show frontogenesis as the front moves into central and southern Utah, allowing for some precipitation, valley rain and mountain snow, to develop along the boundary. Overall, ensemble mean shows the accumulations developing a bit farther northward than what was previously observed, with the precipitation now likely to taper off by the time the front reaches far southern Utah. Overall, accumulations will be on the light side, but it's at least something to talk about after a fairly long period of dry weather.

Unfortunately, the unsettled weather is not expected to persist, with high pressure moving back over the area beginning Sunday. Mostly dry conditions are then expected to persist through day seven, though passing weak waves are expected to provide enough mixing to limit the development of inversion conditions.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions expected for all regional terminals today. Overall light, terrain driven winds prevail for all regional terminals except KEVW where gusty westerly winds are expected to develop again Thursday afternoon. Mid-to-high level cloud coverage is expected to increase across the airspace this morning into the afternoon before clearing out across northern Utah overnight.

SLC WATCHES/WARNINGS/ADVISORIES

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