textproduct: Salt Lake City

KEY MESSAGES

- Anomalous heat with near record high temperatures is once again expected Tuesday.

- Gusty south to southwest winds will develop Tuesday, with around a 60-80% chance of gusts 40-50 mph particularly across many western valleys. Gusty conditions will redevelop across eastern valleys Wednesday. - An unsettled and cooler pattern returns by Wednesday as a trough moves in, bringing periods of valley rain and mountain snow. Following systems look to maintain this pattern into the weekend.

- Locally freezing morning temperatures return to some rural valley locations Thursday through Saturday.

DISCUSSION

Overall synoptic pattern remains fairly unchanged since yesterday evening. Ridging extends through the Rockies while a large scale trough continues to slowly move towards the Pacific coast. Overhead there has been a weak upper level weakness shifting through, which in combination with modest southerly moisture advection has resulted in some isolated terrain initiated showers, but little of substance. Otherwise, the strengthening deep southwesterly flow has just resulted in somewhat breezier conditions through the day along with very mild temperatures.

The aforementioned trough will begin to push inland Tuesday, with southwesterly flow over the Great Basin becoming further enhanced. This will once again result in a very mild day, but also continue to strengthen winds and gusts. While widespread wind gusts in the 20-40 mph range are expected throughout the region through the afternoon, the strongest signal for strong winds is noted across western Utah valleys, and especially the West Desert. These locations have around a 60-80% chance to see gusts more in the 40-50 mph range, and as such a Wind Advisory is in effect from Tuesday afternoon through Tuesday evening. A cold front will start pushing into Utah overnight into Wednesday morning, and winds and gusts across western valleys will relax some in turn behind the front. Eastern valleys ahead of the front however will see another period of gusty winds, with around a 40-60% chance of areas of gusts in the 40-50 mph range.

As the cold front and parent trough advance into the area overnight through Wednesday, precipitation chances will start to increase. With lingering moisture and continued forcing with subtle impulses within the broad trough, periods of showers then continue through Thursday. In general, the orientation of the moisture advection will favor heightened precipitation chances and water amounts north of around I-70/US-50, and particularly for the northern Utah mountains. Forecast water amounts have not changed markedly from prior forecasts, with 25th-75th percentiles for northern valleys still around 0.25 to 0.75 inches, and more around 0.5 to 1.2 inches for northern mountains. With snow levels only falling into the 6000 to 6500 feet range or so, with northern mountain snow accumulation amounts broadly around 3" to 6". With west to northwest flow returning behind the front, will likely see some local orographically enhanced amounts at favored northern terrain closer to 10".

Less certainty is noted in the pattern evolution into the weekend, though models do continue to favor it remaining unsettled. Friday will see a shortwave within a broader closed upper level low sink in, and potentially phase with some southern stream energy through the weekend. Given the complex evolution, models seem to have differences in timing and the degree of phasing, which will in turn influence timing , location, and amount of precipitation. In any case, the pattern should favor at least some flavor of continued unsettled and cool weather.

After the initial cold frontal passage Wednesday, colder air returning with the trough will result in potential for localized overnight freezing temperatures in some rural valleys. The biggest question for Thursday and Friday morning looks to be to what degree cloud cover can clear, as lingering clouds will help keep temperatures from falling as rapidly. As such, looking at around a 10-30% chance for locally freezing temperatures those mornings. A brief intrusion of some drier air Friday night into Saturday morning looks to have the best shot of resulting in better clearing, and freeze probabilities increase accordingly more in the 40-60% chance range.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions will continue with periods of scattered mid and high clouds. Overnight, expect typical drainage winds at most terminals, then south to southwest winds will increase and become gusty by late morning or early afternoon on Tuesday.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Wind Advisory from 11 AM Tuesday to midnight MDT Tuesday night for UTZ101-115-122-123.

WY...None.