textproduct: Salt Lake City

KEY MESSAGES

- Strong westerly winds develop early Wednesday across northern Utah and southwest Wyoming, peaking with a frontal passage in the afternoon. Strongest winds in excess of 60 mph are expected across northwest Utah and Uinta County, WY.

- Expect valley rain and high elevation snow on Wednesday, associated with increased moisture from an atmospheric river.

- Another warm storm brings increased winds and another shot of rain and high elevation snow to northern Utah Friday into Saturday.

LONG TERM (After 12Z/5AM Friday), Issued 325 AM MST

Another atmospheric river event will track into the PacNW Thursday. Through much of Friday, southwest Wyoming and Utah will be between the exiting and incoming storm systems. Upslope orographics and weak forcing will allow for northern mountain snow showers above 7000 feet much of Friday. Also between systems, similar to Wednesday ahead of that atmospheric river, winds will be enhanced. South the southwest winds will be maximized on northern mountain ridgelines and throughout southwest Wyoming.

There is good agreement with models and ensembles that the jet associated with abundant moisture advection will slide southward through Friday, with increasing moisture advection and better forcing pushing into southwest Wyoming and northern Utah Friday into Saturday. Snow levels will start around 7000 feet near the Idaho border and 8000 feet for the Cottonwoods. Snow levels will increase and decrease some, but stay consistent through the event, as the main forcing will be the zonal jet. This will transport abundant moisture, bringing moderate to heavy mountain snow. Snow ratios will be low through the event, ranging from 5-10:1 for the northern mountains, with the greatest ratios for the Bear River Range. Water content will generally range from 0.5-1.0" for the western Uinta Mountains and Cottonwoods, with 0.75-1.5" for the Bear River Range. There will be a big range of snowfall totals, with totals likely exceeding 1 foot for ridgelines near the Idaho border. There will be a decreasing trend from north to south.

Moisture advection will diminish later Saturday as the forcing and moisture lift out of the region, but valley rain and mountain snow showers will continue for southwest Wyoming and northern Utah. Temperatures from Friday into next week will be warmer than normal, with valley highs in the 50s for most locations.

For the end of the weekend into next week, there is good agreement on another atmospheric river event into the western U.S. Models generally have the track of this storm system more southward from the previous. There would be enhanced southwest flow ahead of it, with the better moisture surge north and west of Utah. The track would lead to more downslope orographics to the west from the Sierra Nevada Mountains, so a significant mountain snow event is not anticipated through the start of the week.

AVIATION...KSLC

VFR conditions are expected at the terminal through at least late morning, with cigs likely lowering to or just below 6kft agl between 12-14z. Northerly winds will switch to diurnal southeasterlies around 03z, becoming gusty after 12z.

REST OF UTAH AND SOUTHWEST WYOMING...Winds for northerly terminals will be diminishing this evening, becoming gusty and erratic with incoming showers moving southeasterly from LGU beginning around 11z. Typical diurnal light winds and clear skies are expected at southern terminals through late morning.

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SLC WATCHES/WARNINGS/ADVISORIES

UT...High Wind Warning from 8 AM to 5 PM MST Wednesday for UTZ101.

Wind Advisory from 11 AM to 5 PM MST Wednesday for UTZ102>105- 107-109-110.

Wind Advisory from 11 AM to 11 PM MST Wednesday for UTZ114.

WY...High Wind Warning from 8 AM to 8 PM MST Wednesday for WYZ021.