textproduct: Salt Lake City

KEY MESSAGES

- An atmospheric river event will primarily affect the Pacific Northwest through Wednesday. Southwest Wyoming and far northern Utah will be on the southern extent Tuesday and Wednesday with mountain snow and gusty winds.

- High pressure will be in place Thursday through the weekend, with dry conditions and temperatures around 10-15F warmer than normal. There will also be building valley inversions.

DISCUSSION

Southwest Wyoming and Utah are positioned on the eastern periphery of a ridge near the Pacific coast. Shortwave energy associated with a PacNW atmospheric river event will push into northern Utah Tuesday into Wednesday. Models are in good agreement that the majority of precipitation will be north of Utah, but portions of the state will get rain and snow. Some of those same locations will also get windy conditions.

The greatest precipitation totals will be in the Bear River Range near the Idaho border for locations with upslope orographic enhancement from the west to northwest. National Blend of Models 25th-75th percentile for water values ranges from a few hundredths to around 0.5 inch for far northern Utah and from 0.00-0.10" for the Cottonwoods. Snow levels will rise through the event, starting around 6500 feet Tuesday and reaching around 9000 feet before precipitation ends. Low water content and low snow ratios will result in a light mountain snowfall event, with the upper range for the far northern mountains around 6 inches and totals decreasing quickly southward and at lower elevations.

Winds at 700 mb will increase to around 45 knots Tuesday and Wednesday for southwest Wyoming and northern Utah with the shortwave. This will efficiently translate to gusts of 45-60 mph at ridgelines and throughout southwest Wyoming.

Temperatures through Wednesday will be around 15F warmer than normal with dry conditions for all but southwest Wyoming and far northern Utah.

The ridge near the Pacific coast will track inland after the shortwave exits, so winds will decrease with dry conditions throughout southwest Wyoming and Utah. Temperatures will stay warmer than normal into the weekend, but with lighter winds, valley inversions will set up.

REST OF UTAH AND SOUTHWEST WYOMING

A fairly quiet TAF period is expected across most area terminals, especially southern terminals which will remain clear to mostly clear with light diurnal winds. At northern terminals, especially nearer the ID border, increasing moisture/cloud cover and precipitation chances (~20-40% OGD/EVW/LGU) are noted Tuesday. Higher elevation northern terminals and those in SW WY will see winds and gusts increase through Tuesday.

SLC WATCHES/WARNINGS/ADVISORIES

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