Marine Weather and Tide Forecast for Salt Lake City, UT

.SHORT TERM (Through 12Z/6AM Friday)..Water Vapor satellite imagery this afternoon shows a circulation center over the southern Oregon with broad southwest flow ahead of this feature throughout the Great Basin and into our area. One linear cloud feature embedded in this flow, stretching from central Nevada to southeast Idaho, is associated with light returns on area radars and roughly demarcates the location of a mid-level baroclinic zone per latest model analysis. Northwest Utah has had the most consistent returns this afternoon, while additional weak convection is ongoing over the higher terrain of Nevada just west of the UT/NV border and downstream over southeast Idaho. Much of this precip is struggling to reach the ground though as surface dewpoints are dipping into the 20s. No microburst gusts have been observed as of yet, likely due to the meager instability (90th percentile of surface-based CAPE is only 200 J/Kg or so per the 12Z HRRR over northern Utah). Lastly, south of the baroclinic zone over southern Utah and especially southwest Utah, south winds are gusting to around 30 mph.

The baroclinic zone mentioned above will slide into western Utah by late this afternoon/evening as a weak cold front, then dissipate as it approaches the Wasatch Front mid-evening. Behind this front, most CAMs have sufficient forcing to form a linear area of precipitation over northwest Utah. However, not expecting anything of significance this evening and overnight given meager to non- existent instability and dry low levels. There remains a low chance (<20%) of microburst winds over northwest Utah with this activity. The main impact of this feature will be to increase moisture in the lower levels and help set the stage for a better chance of showers tomorrow.

The aforementioned low and the trough axis associated with it will slide through our area Thursday morning to Thursday afternoon.
Combined with more favorable profiles per model soundings, expecting a better coverage of showers as well as more precip reaching the ground. With more favorable instability vs today, latest guidance even has a 20-30% percent chance of thunder for much of central/northern Utah. Southern Utah looks to remain dry throughout, with another round of breezy south winds gusting up to 30 mph. The trough axis then lifts northeast of the area by Thursday evening, bringing a drying a warming trend.

.LONG TERM (After 12Z/6AM Friday)...Model consensus remains high in the start of the long term forecast period featuring a cutoff (or cutting off) low approaching the California coastline. Initially, limited moisture across the forecast region will only yield low end precipitation chances across primarily the high northern terrain Friday afternoon. Aside from the precipitation chances, enhanced deep southwesterly flow ahead of the low will promote mild temperatures (afternoon highs around 5-15 degrees above normal) and breezy conditions. To the latter point, strongest H7 flow looks to be situated atop southern Utah and Utah's west Desert region, resulting in fairly widespread afternoon gusts in the 30-45 mph range. Current probabilities indicate roughly a 30-40% chance of Wind Advisory level gusts for a sufficient window of time. Moving into Saturday, the large cutoff low slowly churns eastward through the Great Basin and towards the local forecast region. If anything, moisture appears to be lessened as more dry air is wrapped in, so precipitation chances drop. With clearer skies, chances of mixing down the strong H7 flow appear likely over a broader area Saturday, with gusts in the 20-35 mph range across the northern half of the area, and more in the 30-45 mph range elsewhere (maximized across southern Utah and the west desert). If deeper mixing occurs as some guidance suggests possible, stronger wind gusts may necessitate Wind Advisory headlines (~40-60% chance). Temperatures will once again be quite mild.

The low continues on its eastward trajectory, shifting into Utah Sunday. Moisture and precipitation chances will gradually increase within prefrontal southwesterly flow Sunday, remaining elevated into the evening/overnight as the core of the low and associated cold frontal boundary work through. Lingering moisture within the cooler northwest flow will allow for fairly widespread scattered shower activity to persist through Monday. Initial H7 temps around 2C to 6C will drop to roughly -2C to -4C, so in addition to snow levels dropping from around 8000+ ft MSL to 6500-7000 ft MSL, some low end probabilities (~10-20%) of lake enhanced showers are noted Monday.
Forecast water amounts haven't shifted significantly from prior the prior forecast, with higher northern mountains of the Wasatch and Uintas potentially seeing snow accumulation on the order of 2-5" or so. Given the lingering moisture in the likely northwest flow Monday, orographically favored areas such as the Upper Cottonwoods could see a bit more, with around a 40% chance to see 8"+, and 20% chance to see up to 12". While dependent on where exactly some of the shower activity tracks, lower elevations along the Wasatch Front have water/QPF amounts more in the 0.25-0.50" range. So, all in all, decent potential for some soaking rains across northern portions of the forecast region, as well as some late season mountain snow accumulations. As largely implied, temperatures will also fall Sunday and Monday, with highs back near to below normal across the region.

For Tuesday, temperatures begin to rebound as the core of the low shifts southeastward. However, enough moisture will still be around to result in some instability driven showers, primarily across the higher terrain. A very brief period of shortwave ridging brushes through the region into the overnight hours, which then appears to give way to another weaker shortwave impulse upstream. While there is fair consensus in this weak feature, this far out there is much less consensus on any sort of details, so for now forecast just includes seasonable temperatures and low end (~20-40%) precipitation chances.

AVIATION
KSLC...Unsettled weather is expected to continue through the TAF period as a couple weak upper-level systems traverse the region. There is a 30% chance for high-based scattered rain showers to impact the terminal between 22z-02z this afternoon, with potential to produce gusty and erratic outflow winds during this period. An additional line of showers may impact the terminal overnight into Thursday as a weak frontal boundary tracks through northern Utah, though impacts will be limited. Another round of scattered showers are expected after 18z Thursday. Expect typical diurnal trends for winds, with northwesterly winds prevailing through this afternoon, becoming southeasterly overnight.

REST OF UTAH AND SOUTHWEST WYOMING
Unsettled conditions with scattered afternoon showers are expected across the northern half of the airspace today. These showers will be high-based and capable of producing gusty and erratic outflow winds through this evening. A persistent stratus deck is expected through the TAF period, though VFR conditions prevail for all regional terminals.

SLC WATCHES/WARNINGS/ADVISORIES
UT...None.
WY...None.