textproduct: Salt Lake City

KEY MESSAGES

- Periods of precipitation will impact the Beehive State through Friday with temperatures averaging around 5 to 10 degrees above normal.

- There is less than a 30% chance of mountain snow accumulations exceeding 9 inches in the Wasatch Range, 6 inches for the remainder of the Utah mountains in any 24 hour period through Friday.

- The active weather will continue, with the next round of precipitation increasing in likelihood for the second half of the weekend.

DISCUSSION

After tying the daily record high at SLC Sunday (64, previously set in 2015), temperatures have remained elevated overnight ahead of a cold front across portions of northern and western Utah. At 230 AM, the Salt Lake City Airport is still 54F, which is about 12 degrees above the normal high for the date.

Early morning upper air and satellite analysis indicates a shortwave trough embedded in an active and chaotic northern stream is shifting into the northern Intermountain Region. Meanwhile, an upper level low is located off the Baja California coast.

The previously mentioned shortwave trough will push a cold front into far northwestern Utah around 12Z this morning...shifting south and east with time before finally stalling across southern Utah later today. While this front will be in the process of weakening across northern Utah, a band of light precipitation will be associated with the boundary across northern Utah. Expect generally 0.10-0.30" of precipitation across the northern mountains north of I-84, quickly decreasing south of I-84. For the valleys, the heaviest amounts...near 0.15"...can be expected across the Cache Valley, with only a 25% chance of measurable precipitation across the Wasatch Front. This low chance is a combination of very dry pre-frontal conditions (the RH at the SLC Airport this morning is 25%) and weak forcing for precipitation.

Very warm temperatures this morning will fall behind the cold front...so high temperatures for the Wasatch Front and other northern Utah locations will be early...with temperatures falling behind the cold front.

The cold front will lift north as a warm front Tuesday as deep southwest flow ahead of the next shortwave trough builds into the region. Guidance continues to struggle with any member to member coherency in the coverage/development of precipitation in the warm sector Wednesday. While broad upper level diffluence will support precipitation, trying to time subtle impulses embedded in the strong southwesterly flow is difficult at best at this point. In general, expect most valley locations of the state to see somewhere between 0.10-0.25" of precipitation Wednesday (25th to 75th percentile), with some locally higher amounts.

As far as mountain snow during this period, looking at around 2 to 6 inches for the northern mountains, with locally up to 9 inches for the upper Cottonwoods...2 to 5 inches for the remainder of central and southern mountains (both ranges are 25th to 75th percentile). Given these amounts, the probability of advisory amounts is less than 30% for all mountain areas...so no headlines are anticipated.

Utah will remain in southwest flow as an upper level trough continues to stretch across much of the West Thursday. This will keep showery conditions across the state, though below thresholds for any impacts.

By Friday, this trough will finally kick out of the area with another storm possible by the second half of the weekend.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions to prevail for all regional terminals today. A decaying frontal boundary will pass through northern Utah and southern Wyoming sites late this morning into the early afternoon. A band of precipitation accompanying this front will bring lowered CIGS and periods of terrain obscuration for these sites. Otherwise, expect enhanced southerly winds ahead of the front this morning for northern Utah and southwest Wyoming, transitioning northwesterly after the frontal passage. Across southern Utah, expect lighter, terrain driven winds through the period.

SLC WATCHES/WARNINGS/ADVISORIES

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