textproduct: Salt Lake City

UPDATE

An upper level low will shift northeastward across Utah and into southwestern Wyoming through Saturday afternoon. While convection has largely weakened across the region this evening, expect forcing to increase overnight for widespread precipitation north and west of the parent low. This precipitation will focus across northern Utah through at least Saturday afternoon before gradually ending from west to east as the upper level heads into central Wyoming Saturday evening.

Around the western and southern periphery of this precipitation after noon or so Saturday, expect around 200-300 J/kg of SBCAPE combined with 20-30kts of deep layer shear. This may allow for a few briefly organized thunderstorms the southern Wasatch Front east into Castle Country and the western Uinta Basin.

For those with plans across the western Uintas, winter conditions will occur tonight into Saturday evening, especially above 10,000 feet. Those with camping/hiking plans in these areas should be prepared for winter conditions...and even those traveling on Mirror Lake Highway near Bald Mountain Pass may see slushy accumulations on the road.

Updated the aviation section as well as the key messages...the previous general and fire weather discussions follow.

KEY MESSAGES

- An upper level low will bring 0.10-0.50" of rain through Saturday evening to the valleys of northern Utah.

- Winter conditions will occur across the western Uinta Mountains through Saturday evening, largely above 10,000 feet. 1 to 5 inches of snow will accumulate above 10,000 feet with isolated totals up to 7 inches above 11,000 feet.

- Beginning as early as Wednesday, the probability of moderate HeatRisk increases to above 40% across the Wasatch Front and many other lower elevation areas of northern and central Utah.

DISCUSSION

Last updated 1158 AM MDT Fri May 29 2026

The broad low which has remained across the western US for several days will finally begin more of an eastward progression through the Great Basin through Friday. Already seeing moisture associated with this increasing, as evidenced by area radars picking up on shower activity across southern Utah. With increased cloud cover and the low helping to shift the ridge, temperatures are running a bit cooler today and will peak at levels lower than yesterday's high.

As the core of the low continues to shift east, synoptic forcing for ascent will increase across the area, initially favoring southern Utah with coverage later on shifting to areas further north. In general this moisture is more concentrated around the mid levels, supporting higher based showers and thunderstorms. As such, given mean afternoon destabilization on the order of around 100-300 J/kg along with 25-35 kts bulk shear, will see activity capable of producing gusty and erratic outflow wind gusts. In general, think most activity will support gusts in the 35-50 mph range or so. However, it does appear a corridor of enhanced DCAPE may develop across portions of south central to southeast Utah, supporting around a 5% chance of severe gusts in excess of 58 mph. For this area, the SPC has indicated a categorical "Marginal Risk" of severe weather, risk level 1 of 5. As activity shifts further north later in the day, waning instability and increasing saturation should begin to limit the gusty wind threat.

While storms Friday afternoon are expected to be somewhat higher based in nature, there still will be a nonzero threat of locally excessive rainfall in any storm that becomes more organized. Generally, anticipate this to mostly be a threat to more rain sensitive basins such as slot canyons and dry washes across southern Utah. As such, opted to add "Possible" to the Flash Flood Potential Rating for many southern Utah parks and recreation areas. Those planning recreation in such places will want to keep an eye on the weather, or consider alternatives on other less rain sensitive locations.

Late Friday evening on into Saturday the low will start to eject more northeastward through Utah and into southwest Wyoming and northwest Colorado. The highest concentration of moisture will wrap around into the core of the low, which will also have favorable synoptic forcing even with more limited instability. As such, should see a more persistent area of showers and stratiform rain across northern Utah and southwest Wyoming as the low gradually tracks through. Models continue to support fairly widespread amounts of around 0.10" to 0.25" for much of the Wasatch Front, and potential for an area more in the 0.50" to 1.00" range where a deformation axis may set up around the low. Right now the rough consensus for such a band is around the Weber/Davis County area, though the exact track of the low will dictate where it ultimately may set up. Also think there could be a favorable upslope component with the low shifting east of the terrain, allowing benches to squeeze out a bit more. The EFI also highlights the Uintas on through Uinta County, WY with signal for climatologically anomalous precip, which tracks with the current forecast low progression. Currently have around 0.50" to 1.00" water for these areas, but wouldn't be surprised to see some locally higher amounts.

Despite it being the end of May, this storm system does actually look to have enough cold air with it to result in some high elevation snow. That said, outside of any rate driven reductions, snow levels don't look to far much lower than around 9500 feet at best. Given the signal for higher water amounts across the Uintas, the higher locations generally above 10000 feet look to actually see accumulating snowfall. Generally these amounts are in excess of 4", with potentially up to 10" in the higher reaches, though mild antecedent conditions and dense nature of the snow will likely help to limit accumulation to an extent. While no Winter Weather headlines appear necessitated, those planning recreation in the high Uintas or travel through open seasonal roads such as Mirror Lake Highway should be prepared for snow.

Temperatures through the weekend fall to around 5-10 degrees below seasonal normal as the low moves through. This looks to be short lived though, as ridging then appears favored to become the increasingly dominant influence on the forecast area once again. With that, forecast carries a warming trend through the upcoming week along with limited precipitation chances.

REST OF UTAH AND SOUTHWEST WYOMING

Isolated showers still over southern UT late Friday evening will gradually diminish by 06z or so. Across central/northern UT and SW-WY, rainfall will persist through the overnight hours, with CIGs dipping down to MVFR between 08-16z (IFR across higher elevations such as KEVW). Showers will gradually shift eastward during the afternoon, with rainfall finally exiting out of SW-WY after 03z Sunday. Winds will be much lighter overnight compared to earlier this afternoon.

FIRE WEATHER

Last updated 1158 AM MDT Fri May 29 2026

Southerly wind gusts Friday around 25-35 mph in combination with minimum humidity values around 15 percent will result in elevated to locally critical fire weather conditions across eastern valleys where fuels are sufficiently dry. Additionally, an area of low pressure will gradually move in and lift northeastward through Utah Friday into Saturday. For Friday this will result in showers and thunderstorms during the afternoon to early evening, with activity initially favored over southern Utah, shifting northward late evening into the overnight hours. This system will provide around a 30-60% chance of wetting rains for the southern and central mountains, 40-70% chance for northern mountains, and a greater than 80% chance for the Uintas. Additionally, temperatures will be cool enough with the system to bring accumulating snow to the high Uintas, with 4" or greater expected above 10000 feet, and locally up to 10" possible in the higher reaches.

Following the low pressure system departing, high pressure is favored to build back into the region and become the dominant weather influence. This will start a warming and drying trend from Sunday onward into the upcoming week. Temperatures will push to around 5 to 10 degrees above normal, and afternoon humidity values will largely fall back into the low teens to single digits.

SLC WATCHES/WARNINGS/ADVISORIES

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