textproduct: Salt Lake City

KEY MESSAGES, Issued 1036 PM MDT Sat Oct 17 2026

- Isolated showers and thunderstorms return to southern and central Utah Sunday and Monday.

- Widespread precipitation chances return as early as Tuesday and continue on through Friday. Forecast water amounts are around 0.50" to 1.50", with locally up to 2.00" or so in favored high terrain.

- Modest snow accumulation of around 3" to 6" will be possible above 9500 ft or so as snow levels dip Thursday into late Friday.

DISCUSSION, Issued 1036 PM MDT Sat Oct 17 2026

A weakening upper low centered near the far SoCal coast continues to spread moisture north through Arizona ahead of it. This moisture is enhanced by remnants of former Tropical Storm Simon. Precipitation associated with the moisture is noted over/near the Utah/Arizona border this evening.

As the storm continues to fall apart Sunday and Monday, weak vort lobes are progged to eject into Utah. Otherwise, the bulk of the remnant energy will move across Arizona. With abundant moisture but weak dynamics, expect mainly spotty showers or disorganized bands of precipitation through Monday associated with this storm, mainly over southern and central Utah.

Attention then shifts to the next storm system, which will develop into a closed low off the central Cal coast by Tuesday. With diffluent flow aloft, expect precipitation to increase on Tuesday ahead of this storm. The upper jet aiding the upper diffluence will move out by Wednesday, and with the upper low still positioned off the coast, Wednesday could see a relative lull in precipitation. The low is then progged to move inland on Thursday and across Utah on Friday, bringing a period of more widespread precipitation to the area. Some moisture from remnants of what is currently Hurricane Trudy near the west coast of Mexico may catch portions of Utah during this time. Additionally, as cooler air arrives late Thursday into Friday snow levels will lower, potentially falling to as low as 8kt. However, subtle differences in the track and evolution of this low will have an effect on the eventual snow levels, which could remain above 9kft based on some solutions.

Overall, the NBM has a general 1 to 2+ inches of QPF in the mountains from Tuesday through Friday, with around half of that in most valleys. The snow amount forecast will be trickier due to aforementioned snow level uncertainties, but the current NBM has 2-7 inches along the higher ridgelines (generally above 9000 ft).

Beyond Friday, greater models spread exists. While many solutions have the storm system out of the area for Saturday, around 55% of global ensemble members have some remnant troughiness hanging back over Utah (something which has been especially favored by the latest runs of the GFS and its ensemble members). This would maintain cooler and unsettled weather over the area into next weekend, compared to the drier solution offered by the EC and a minority of global ensemble members.

AVIATION

KSLC...VFR conditions will prevail over the terminal through the valid TAF period under increasing mid- and upper-level cloud cover. Light southerly winds are expected to remain in place through the morning, with northerly winds returning around 20-21Z.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will prevail across the area through the valid TAF period. Areas of light rainfall are expected across southeastern Utah through the morning hours, moving into east-central Utah in the afternoon.

SLC WATCHES/WARNINGS/ADVISORIES

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