textproduct: Salt Lake City

KEY MESSAGES

- Strong southwesterly winds develop late this evening into early Wednesday morning ahead of a frontal passage, with gusts 45-55 mph likely across the West Desert and portions of the Wasatch Front.

- A strong cold front moving through the region late tonight into early Wednesday will bring widespread accumulating snow, even to valley floors.

- A weaker system brings chances for accumulating snow mainly to central and southern Utah late Thursday into Friday.

DISCUSSION

Current radar imagery shows scattered showers ongoing across the region this afternoon. These showers will continue to produce spotty accumulations, mainly snow outside of lower Washington County, through this evening. Any impacts from these showers will be overall minor today, mostly confined to brief slush-ups under heavier cells over mountain routes.

Winds will be the main concern ahead of a cold front passage tomorrow morning, with increasing southwesterly flow aloft resulting in strong winds developing across the West Desert and portions of the Wasatch Front including the Salt Lake Valley this evening. Gusts 45-55 mph are expected to develop after roughly 10 PM tonight, continuing until the front passes through Wednesday morning. There is a 30% chance for gusts to exceed 55 mph at times through this period, mainly along the I-80 corridor through Tooele County. Travel will be difficult during this period, especially for high profile vehicles.

A band of heavy precipitation is still on track to accompany the cold front passage as it sweeps southeastward through Utah and southwest Wyoming beginning early Wednesday morning. Snow levels dropping to around 4000 feet behind the front will result in the first notable valley snow event so far this season, with a general 1-4 inches expected for the Wasatch Front Wednesday morning into the afternoon. The best chance for accumulating snow across the Wasatch Front will occur with the heavy snow band accompanying the frontal passage, with current guidance showing the timing of this passage anywhere between 6 AM-11 AM. Impacts to the morning commute will be possible as a result.

Across southwest Utah, heavy snow is expected to develop ahead of the cold front passage as a strong mid- level jet moving into southwest Utah late this evening results in invigorating shower activity across the area. Strong, moist southwest flow during this period (H7 winds around 60 kts) will favor orographic enhancement across the Markagunt Plateau (Brian Head area), with an extended period of snow rates in excess of 2 inches expected as a result until northwest flow develops late morning behind the cold front passage. Another area that may see locally higher snow totals from this southwest flow includes the Black Ridge Canyon, where heavy snow will likely impact travel at times late tonight into Wednesday morning.

Post-frontal northwest flow will keep snow showers lingering through the evening, diminishing areawide by early Thursday morning. Cold and dry conditions will settle in Thursday, though dry conditions will be brief as another trough is expected to dig into southwest Utah late Thursday into Friday. This system is expected to bring additional chances for snow showers, mainly to central and southern Utah.

REST OF UTAH AND SOUTHWEST WYOMING

Showery activity at the northern terminals is expected to wind down this evening as southerly winds pick up ahead of a strong cold front arriving in the Wasatch around 15z. This front will bring snow and IFR to LIFR CIGs and VIS conditions for most airports. Southern terminals will see gusty winds continue through the night, with brief periods of intense precipitation after 05z and IFR to MVFR conditions into the morning hours.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Wind Advisory from 10 PM this evening to 6 AM MST Wednesday for UTZ101-102-105-115.

Winter Weather Advisory from 3 AM to 3 PM MST Wednesday for UTZ102>106-116.

Winter Storm Warning from 3 AM to 5 PM MST Wednesday for UTZ107.

Winter Storm Warning until 5 AM MST Thursday for UTZ108-110>113- 117.

Winter Storm Warning from 8 PM this evening to 5 PM MST Wednesday for UTZ122-127.

Winter Weather Advisory from 8 PM this evening to 5 PM MST Wednesday for UTZ124-126-128.

Winter Storm Warning until 5 PM MST Wednesday for UTZ125.

WY...Winter Weather Advisory until 5 PM MST Wednesday for WYZ021.