textproduct: Salt Lake City

KEY MESSAGES

- Gusty south to southwest winds up to 50 mph will impact most eastern valleys through 6 PM today.

- Strong northwest winds up to 55 mph will develop behind the cold front across Castle Country near and along the SR-10 corridor through 5-6 PM today.

- An additional 0.10-0.25" of northern valley rain and 2-6 inches of northern mountain snow can be expected through Thursday. The Bear River Range will see local amounts up to a foot.

- Freezes will impact many Utah valleys tonight and again Thursday night. Freezes are not expected to impact the Wasatch Front or lower Washington County.

- An active pattern will bring the threat of 6+ inches of snow to the northern mountains Saturday night into Monday.

- Additional freezes may impact the Sanpete and Sevier Valleys and southwest Utah Sunday night into Monday morning.

DISCUSSION

An active 7 to 10 days is on the horizon across the Beehive State, with multiple rounds of precipitation expected.

Late morning upper air and satellite analysis indicates an upper level low is shifting across the northern Intermountain Region. The associated cold front continues to cross Utah, bringing a period of strong west to northwest winds. Any elevated winds will decrease near 6 PM. Wind advisories remain in effect...and no changes were made with this package.

Given the strength of this cold front, colder temperatures will shift into the region in its wake. Freezing Warnings remain in effect for many central and southern Utah valleys currently in their growing seasons for tonight into Thursday morning, though freezing temperatures are not expected to the Wasatch Front or lower Washington County. Another cold night is expected Thursday night into Friday morning and thus Freeze Watches are now in effect for all the same valleys as tonight with the addition of eastern Box Elder County.

After several days of gradual warming, a series of upper level lows will begin to impact Utah Saturday afternoon, continuing through at least early the next week. While there is a wide spread in timing, strength and even orientation of the various potential shortwave troughs and upper level lows, the main message is increasing in confidence: temperatures at or below normal will combine with periods of precipitation through the period for most of the state. The current deterministic NBM (National Blend of Models) indicates valleys north of Nephi will see 0.50-1.00" of rain between 00Z Sunday and 00Z Tuesday, with valleys across central southern Utah seeing lower values closer to 0.10-0.50". Based on the current deterministic snow levels and snow ratios, the northern mountains would see around 6 to 12 inches of snow over this time period, with locally up to 18 inches in the upper Cottonwoods. The central and southern mountains would be closer to 4 to 8 inches. But those are deterministic values. If, for example, we look at the 10th to 90th percentile for the upper Cottonwoods, the variability in the ensembles become more obvious. This range is currently 0.40-3.20 inches. The Salt Lake City Airport, as another examples, shows a significant variability between the 10th and 90th percentile: 0.10-1.40 inches. This period of active weather will be something to watch as the ensemble members start to cluster more meaningfully into particular solutions.

REST OF UTAH AND SOUTHWEST WYOMING

Low clouds and area isolated to scattered showers will continue across the northern half of Utah and southwest Wyoming through the remainder of the daytime hours before conditions improve overnight. That said, a trailing area of isolated showers are expected to develop during the overnight hours, primarily impacting terminals along the Wasatch Front. These showers may persist through the morning hours.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Freeze Watch from Thursday evening through Friday morning for UTZ103-114>116-118>120-122.

Freeze Warning from 10 PM this evening to 10 AM MDT Thursday for UTZ114>116-118>120-122.

Wind Advisory until 6 PM MDT this evening for UTZ120.

Wind Advisory until 6 PM MDT this evening for UTZ121-128>131.

WY...None.