textproduct: Salt Lake City

KEY MESSAGES

- Strong winds will continue across the northern Wasatch Mountains and western Uinta Mountains into the evening.

- A cold front will across northern Utah Saturday afternoon into Saturday evening, bringing strong west winds to the northern Wasatch Mountains, western Uinta Mountains, western Uinta Basin and Castle Country. Isolated thunderstorms will occur near this front across northern Utah.

- One last mainly dry cold front will cross the region Monday.

- Anomalously strong high pressure will build into the West behind this front Tuesday, with temperatures averaging near 20 to 30 degrees above normal. Some locations will flirt with all time record highs for March by Thursday.

DISCUSSION

Early afternoon upper air and satellite analysis indicates strong ridging remains in place across the eastern Pacific. An active northern stream continues to shift into the Pacific Northwest with a 170kt+ jet max stretching across the Montana into the High Plains. Afternoon observations suggest wind gusts in excess of 55 mph are widespread across the northern Wasatch Mountains and western Uinta Mountains. Across the western Uinta Basin, wind gusts up to 40 mph are being reported, while wind gusts largely up to 55 mph are being reported across Uinta County, WY.

700mb flow near 50kts will continue across portions of northern and eastern Utah (and Uinta County, WY) through the evening. Current wind headlines are on track and no updates are needed at this time...though will continue to monitor winds in the western Uinta Basin and Uinta County, WY.

As a brief period of shortwave ridging occurs across the West Friday, winds will decrease across northern and eastern Utah. This has a high probability of decreasing winds sufficiently below advisory thresholds, though gusty winds will continue.

By Saturday, another deepening shortwave trough will cross through the Pacific Northwest into the Great Basin. Guidance has shifted the timing of this cold front a bit later than yesterday's runs...which also trended the wind gust potential lower than previous guidance. The probability of winds exceeding 58 mph across the western Uinta Basin, Castle Country has decreased to less than 15%. Given this, while confidence is high in advisory level winds across the area and the northern Wasatch Mountains and western Uinta Mountains, do not have 50% or greater confidence in warning conditions. Held off on any additional wind headlines across these areas for Saturday for this reason, but given model trends, advisories may need to eventually be issued.

The other impact to be expected near this front continues to be isolated thunderstorms and minor snow accumulations (1 to 3 inches, largely above 9000 feet) Saturday. Given steep lapse rates, thunderstorms may have periods of graupel that can make conditions briefly slick. No organized convection is expected though.

After another mainly dry cold front Monday, strong high pressure will build into the region Tuesday. By Thursday, the EC based Extreme Forecast Index shows values pegged to the peak of the charts across southwestern Utah, with high values through the remainder of the state. The National Blend of Models deterministic max temperature for Salt Lake City Airport by Thursday is 82F, which would break the all-time record for March (80F on 3/31/2012). Looking at the probability of reaching a 700mb temperature of 8C (correlates to 80 at KSLC with a dry adiabatic lapse rate), the LREF suggests around a 76% chance the 700mb temperature will meet or exceed 8C. This correlates well with the current deterministic NBM. Current deterministic NBM forecast for Thursday for St. George is 96F. The previous earliest 96F or higher on record for St. George is April 15. Needless to say, unless there is a substantial change in the guidance, record breaking temperatures will be here by midweek.

REST OF UTAH AND SOUTHWEST WYOMING

Winds will increase out of the west-northwest this afternoon across mainly northern UT/southwest WY, with most locations gusting up to 20-30kts. Southwest WY is expected to reach 35-45kts, with a 20% chance of exceeding 50kts at KFBR in particular. Winds will drop off after 01z, though gusty winds up to 20kts are likely to continue overnight in southwest WY. VFR conditions will prevail.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Wind Advisory until 9 PM MDT this evening for UTZ110-112.

WY...None.