textproduct: Salt Lake City

KEY MESSAGES

- Well above normal temperatures (+15-20 degrees) spread back into Utah and southwest Wyoming through at least Tuesday.

- A series of weak weather disturbances will pass through northern Utah and southwest Wyoming Sunday into Monday, bringing another round of high elevation snow (8,500ft+) and valley rain, primarily for areas near the Utah/Idaho border.

- Winds will be breezy at times through Tuesday, primarily over western Utah, before becoming stronger Wednesday into early Friday with the arrival of another warm Pacific storm system.

- Another warm storm system will impact the area early next week, bringing mountain snow and valley rain across Utah.

LONG TERM (After 12Z/5AM Wednesday)

An upper trough is forecast to park itself off the West Coast to kick off the extended forecast. This trough is expected to gradually amplify throughout Wednesday with enhanced southwesterlies overspreading the intermountain west within a diffluent flow regime. This will result in an atmospheric river transporting ample moisture to the region resulting in persistent and widespread precipitation across the forecast area Wednesday through at least Friday.

On Wednesday, winds increase in magnitude across the region as a deepening shortwave embedded within the already enhanced mean flow traverses across northern UT throughout the day. This shortwave is expected to overlap with the arrival of moisture within the atmospheric river kicking off a prolonged period of precipitation across the entire forecast area. Snow levels are expected to remain high due to the warm nature of atmospheric rivers, keeping most valley locations socked in with rain. This general pattern is expected to persist through at least Thursday as the upper trough remains parked off the Pacific Coast.

Compared to last nights forecast, ensemble guidance appears to have a better handle on Friday, keeping the trough parked off the West Coast into the afternoon before it begins ejecting inland. After it begins ejecting and into Saturday, however, ensembles begin to diverge regarding timing and especially the general upper air pattern that we can expect. The current 00z suite of operational long-range guidance indicates a split flow regime with an upper trough grazing northern UT and a cutoff low ejecting east into southern CA. Diving into ensemble guidance, however, reflects the uncertainty regarding this despite guidance gradually trending toward this solution over the past few days. As of now, it still remains a nearly 50/50 split amongst all global members with 50% supporting higher geopotential heights across southwest Canada, yielding a southern track supporting the possible development of a cutoff low. The other 50% supports slightly lower geopotential heights to our north, allowing the upper trough to progress east and not cut off to our south. Timing is quite difficult to iron down as each solution remains quite uncertain within cluster analysis, though what we can assume is that an open wave would yield a more widespread precipitation event for the entire forecast area while a southern cutoff low would generally favor more precipitation across the southern half of the state.

Finally, temperatures will run quite warm through the majority of the extended forecast period with temperatures 15-20F above average expected through Thursday. We are expected to cool off briefly on Friday as "colder" air pushes in on Friday, though we will remain around 10F above average for most locations. With no valley snow in the forecast, we will continue nudging even closer to the latest measurable snowfall at SLC, with that date being January 2nd. Anything past that will set the new record for latest measurable snowfall for SLC since records began.

REST OF UTAH AND SOUTHWEST WYOMING

Enhanced south southwest flow will develop across the airspace, except for KSGU due to sheltering. Gusts will increase throughout the morning hours with the majority of our sites seeing gusts in excess of 20kts. There is a chance that KEVW sees wind gusts in excess of 40kts following 18z for a couple hours. Across northern UT and southwest WY, scattered showers are possible into the mid afternoon with ceilings perhaps leading to mountain obscurations. Winds are expected to remain elevated throughout the TAF period, though ceilings are expected to improve near the end of the TAF period.

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SLC WATCHES/WARNINGS/ADVISORIES

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