textproduct: Salt Lake City

KEY MESSAGES

- Building high pressure keeps conditions dry and mild through the weekend.

- A cold front will bring valley rainfall and mountain snowfall beginning as early as Monday evening lasting into Tuesday.

- A shift to a cooler and unstable pattern will follow for the remainder of next week.

DISCUSSION

A weak upper trough is currently clipping the western portion of UT this afternoon bringing isolated rain showers to southwest UT. These showers should quickly diminish around sunset as instability begins to weaken. Following the departure of this trough, a closed low will pass through southern AZ with a transient upper ridge poking its northern axis into the Great Basin. This will yield generally mild and dry conditions through the weekend.

Come Sunday evening into Monday morning, a broad trough is forecast to push into the Pacific NW with diffluence beginning to overspread much of UT by Monday afternoon. This system has trended somewhat faster and perhaps a tad drier with the trough axis and attendant cold front pushing through northern UT in the late afternoon through the evening hours. As such, PoPs have increased across the majority of northern UT with this forecast cycle, though rainfall/snow accumulations have decreased with a drier and weaker frontally forced band of convection pushing through. Following the passage of this frontal feature and the upper trough continuing east, north- northwest flow will fill in behind with increasing diffluence aloft ahead of another incoming trough through south-central CA. Despite the possibility of a semi unfavorable wind direction for orographic lift across our northern mountains, ample ascent may help compensate for this. Additionally, if the aforementioned frontal feature were to stall across northern UT with increasing diffluence aloft, some locally heavier precipitation along the frontal boundary may occur, though this remains highly uncertain. At a minimum, it will at least bring some breezy conditions to the forecast area on Tuesday.

With increasing ascent as the trough continues to push further east, snowfall rates will increase later in the afternoon on Tuesday for higher elevations across the entirety of the state with the majority of our lower elevation locations seeing light rain showers develop. As the trough passes by through Wednesday morning, valley showers will begin to diminish with ascent gradually weakening, though north- northwest flow and residual moisture aloft may keep snow showers persisting across higher terrain across the state through Thursday.

Looking even further, the pattern does appear to remain active following these systems. Ensemble cluster analysis continues to indicate a western trough in some capacity following Friday, though considerable uncertainty exists regarding southern extent and if any geopotential heights are able to build in over the eastern Pacific. This would shift the trough further east than we'd necessarily want in this case (30% of ensemble members support this) as it could keep us cold and dry. Regardless, there exists a multitude of outcomes for the long term at this time though the future may hold some promise.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions are anticipated to be maintained with just some mid/high clouds lifting through into Saturday. Anticipate most terminals (outside of higher unsheltered terminals such as EVW) to see light winds less than 10 kts, with diurnally typical directional shifts.

SLC WATCHES/WARNINGS/ADVISORIES

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