Area Forecast Discussion
Issued by NWS Salt Lake City, UT
Issued by NWS Salt Lake City, UT
898 FXUS65 KSLC 272225 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 325 PM MST Thu Nov 27 2025 .SYNOPSIS...Dry conditions persist through Friday afternoon before a cold and unsettled weather pattern kicks off Saturday through the extended. While specifics continue to remain somewhat uncertain, mountain snowfall is expected across northern UT this weekend with a chance at light valley accumulations Sunday morning. && .DISCUSSION...Key Points: - Dry, mild conditions persist through Friday afternoon. - Cooler temperatures and chances for precipitation return late Friday night through Sunday featuring high elevation snow and perhaps a shot at light valley accumulations primarily across northern UT. - Following this weekends system, an active upper level pattern looks to continue with our next chance of precipitation occurring across northern UT and southwest WY on Tuesday. - Slightly below to near normal temperatures are expected to develop Saturday, lasting through at least next Thursday. Today, an upper ridge over the area continues to retreat south as incoming shortwave trough moves inland across the Pacific NW yielding generally westerly flow aloft. Modest upper level moisture continues to stream into the region resulting in light cirrus overspreading the region which will continue to increase in coverage through this evening as more moisture progresses east. Seasonably warm temperatures continue today keeping conditions mild and pleasant, though this forecaster is sure that the majority of the audience would be thankful for more snow than we`ve had up to this point. An upper level shortwave trough is forecast to dive southeast from the Pacific Northwest tomorrow, clearing through the forecast area by Saturday evening. This is expected to be the first trough to pass through the area with this weekends wave train, though impacts are expected to be quite minimal as forcing remains weak due to the trough deepening well after it passes us to the east. On a more localized scale, this system will bring light snow accumulations to higher elevations of the Bear River Range with around 1-5" expected on Friday. On a larger scale, this system will sweep a dry cold front across the forecast area bringing daily temperatures to near- normal or just below normal for the majority of the forecast area. Additionally, it will also serve to drop snow levels across northern UT and southwest WY, setting the stage for the second shortwave trough to impact the region this weekend. The next trough looks to dive down from the Pacific NW once again, arriving at the forecast area late Saturday evening to early Sunday morning. The majority of Saturday should remain dry across the forecast area, though a few isolated snow showers across higher terrain can`t be ruled out within a diffluent flow regime ahead of the incoming shortwave. Come Sunday, snow levels will remain quite low as a result of Friday`s system ranging from 3500-4500ft along a north-south gradient across northern UT and southwest WY. Regarding Sunday, there is high confidence that a shortwave trough will slide southeast through the Great Basin. However, uncertainty still exists regarding the east-west extent of the trough and how/if it will deepen before reaching our area. An open wave would yield weaker ascent across the forecast area likely resulting in less storm coverage and weaker precipitation rates from any showers that do form. The opposite is true with a deeper, more compact trough solution where stronger ascent would yield increasing storm coverage with higher precipitation rates. Likewise, solutions that keep the trough off to our east may result in notably less precipitation across the area, perhaps little to none at all in some instances. Solutions with a trough further to our west typically yield precipitation amounts closer to the higher end of the range of accumulations across ensemble members. Lastly, ensemble clusters capture this uncertainty with three different solutions. Roughly 20% of all members capture a scenario with a deeper western trough which would favor more widespread activity. The second solution with around ~60$ of all members keep the wave open, likely resulting in less widespread activity and reduced precipitation rates. Finally, the "bust" solution with around ~20% of all ensemble members takes the system south of us, perhaps forming a cutoff low, which would likely yield little to no activity across northern UT and shift everything to southern UT. This uncertainty is reflected well in DESI with a 25th-75th percentile spread for snowfall ranging from 3" to 9" across the Wasatch and 1" to 5" across the Bear River Range. Lastly, given 700mb temperatures ranging from -7C to -10C across northern UT and the lower snow levels on Sunday, valley accumulations wouldn`t be entirely out of the question early Sunday morning across northern UT, though any accumulations are expected to be light at this time. To sum this up, this remains quite a difficult forecast to iron out at this time and continues to have at least some "bust" potential. As we enter the workweek, an upper air pattern for favorable storm tracks persists and will continually usher in cold air aloft via northwest flow. Our next shot for precipitation develops late Monday evening through Wednesday at the latest as another trough is forecast to dive southeast from the Pacific Northwest. Uncertainty also remains high with this system as the strength of the trough, positioning, and timing is questionable, similar to Sundays system. Details are expected to be ironed out more over the coming days. Following this system, the pattern continues to remain favorable for more storms to follow in the extended. && .AVIATION...KSLC...The SLC terminal will see VFR conditions through the night with some high clouds. Northerly winds are expected to shift to the south between 02Z and 04Z. .REST OF UTAH AND SOUTHWEST WYOMING...The airspace will see VFR conditions through the evening with some high clouds. Winds will be generally light and diurnally driven. && && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && $$ PUBLIC...Worster AVIATION...Traphagan For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity