textproduct: Salt Lake City

KEY MESSAGES

- Winter Weather Advisories remain in effect for our northern and southern UT mountains through Thursday morning.

- Snowfall rates across our northern mountains look to maximize from 9PM-3AM this evening, potentially in excess of 1"/hr at times (40- 60% chance).

- Snowfall rates across our southern mountains look to maximize from now to around midnight, potentially in excess of 1"/hr at times (30- 50% chance).

- A brief lull is expected with weather this weekend, though the pattern becomes favorable for another active stretch starting Monday of next week.

DISCUSSION

An upper low is currently located over central CA with an attendant positively tilted trough to its southwest. Upper diffluence from the trough will continue through tonight, resulting in another round of precipitation across UT with the highest rates occurring along a north progressing warm front across northern UT this evening. Across northern UT, a lull in precipitation has been observed this afternoon with storms expected to reinvigorate once again by 1700 with precipitation coverage increasing as series of midlevel shortage perturbations pass through the area. Regarding snowfall, the forecast remains on track with generally 6-12" expected across our northern UT mountains (locally higher amounts to 15" in the Upper Cottonwoods and high Uintas) as well as around 6- 12" for the remainder of our UT mountains. For northern UT, a period of snowfall rates potentially in excess of 1"/hr looks to occur around 9PM-3AM this evening (40-60% chance of at least 1"hr during this timeframe), particularly across the Upper Cottonwoods and perhaps the Wasatch Back. Additionally, there is a 30-50% chance of at least 1"/hr rates across the Tushars and Brian Head right now through around midnight. UDOT RWIS indicated that 1"/hr rates were observed around Brian Head earlier this morning with a few other instances nearly reaching 1"/hr.

Over time into tomorrow afternoon, a secondary upper low will develop closer to the trough axis with height rises occurring across the northern Rockies. This will cause the current upper low to dive south somewhat with the trough deepening as the secondary low closer to the trough axis also intensifies. Additionally, this will result in ascent gradually weakening across UT and SW WY through tomorrow evening. Transient ridging quickly builds in behind this system as it progresses east, bringing warm and dry conditions back to the forecast area Friday through Sunday.

This ridge will slide east on Monday as a highly amplified longwave trough begins to push into CA. Not only is there quite high ensemble consensus with this setup next week, the systems appear colder than what we have had thus far this winter (or lack thereof). As such, ensemble probabilities for at least an inch of snow ranges from around 30-50% from Tuesday into Wednesday. This is a slight decrease in confidence from the previous forecast cycle, though this is expected given how far out this event is. Regardless, next week does appear to be our best shot at potentially notable accumulations across our mountains and valley snow in what feels like forever.

REST OF UTAH AND SOUTHWEST WYOMING

Winds ranging from southeast to southwest, with gusts around 20 knots, will taper off around 00Z. Broken to overcast clouds in VFR range will prevail through the TAF period. Scattered showers will be most common during the overnight hours. VFR conditions will prevail, but rain showers will be capable of lowering conditions into MVFR range for short durations. Snow showers for southwest Wyoming will be capable of LIFR or IFR conditions. Showers will largely taper off by 12Z, with dry conditions through around 20Z when more scattered showers build.

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SLC WATCHES/WARNINGS/ADVISORIES

UT...Winter Weather Advisory until 11 AM MST Thursday for UTZ110>113.

Winter Weather Advisory until 5 AM MST Thursday for UTZ125.

WY...None.