textproduct: Salt Lake City

KEY MESSAGES, Issued 1008 PM MDT Wed Oct 7 2026

- Widespread moderate to heavy rainfall threat increases late Saturday through Tuesday as a remnant tropical system and associated deep moisture lift through and interact with an approaching trough. Widespread water amounts of 1 to 2 inches are forecast, with locally higher amounts in excess of 3 inches possible in areas of southern Utah and high terrain.

- Per the National Hurricane Center track, Hurricane Rachel is favored to weaken following landfall, with the post-tropical storm/depression lifting through Utah Sunday into Monday. This period is expected to see the highest threat of heavy rainfall.

- By Sunday, a slight risk for excessive rainfall (level 2/4) is noted over much of southern Utah, and a marginal risk (level 1/4) elsewhere. There is potential for further expansion in subsequent days as the forecast window progresses forward. Excessive rainfall will be most likely over rain sensitive basins (burn scars, slot canyons, typically dry washes, and slickrock areas).

DISCUSSION, Issued 1008 PM MDT Wed Oct 7 2026

Another mild day across the region today as ridging remains the dominant influence. While most areas remained dry, sufficient moisture beneath the ridge did spark some isolated afternoon showers and thunderstorms across Utah's high terrain, but dry conditions are overwhelmingly favored overnight into Thursday. Otherwise, temperatures were once again quite mild with afternoon highs around 10 to 15 degrees above normal. Through Friday, there is minimal shift in the overall forecast pattern, and as such the day to day weather looks to be very similar to that of Wednesday's.

The forecast will begin to change substantially Saturday on into early next week. The primary two forecast elements in play are the remnants of now Hurricane Rachel approaching from the south, and a deepening northern stream trough digging towards the region through the PacNW. Deep tropical moisture will start to overspread the region, with a corresponding increase in precipitation chances as it does so. The chance for widespread moderate to heavy rainfall then becomes maximized in the Sunday to Monday time frame as the core of Rachel's remnants lift through and interact with the deepening trough. While there is still some uncertainty in Rachel's exact track, models have honed in enough to where there are very few ensemble members on the drier side of solutions for Utah and southwest Wyoming.

In regards to the placement of the higher rainfall totals, guidance still favors portions of south to southwest Utah, as well as much of Utah's high terrain. Even then, the 25th to 75th percentile has maintained widespread 1 to 2 inch rainfall amounts across the majority of the forecast region, including areas further north. If anything, rainfall amounts have slightly increased from the prior forecast. Locally, the forecast also continues to support higher amounts in excess of 3 inches in portions of southwest Utah, and high terrain in northern Utah.

While uncertain, how exactly the trough interacts with Rachel's remnants may yield another local maximum in rainfall. This would occur as a front from the northern trough sinks into the area, and the northern jet then phases/couples with the southern sub- tropical jet as deep tropical moisture continues to lift through overhead. So far placement for such a feature leans towards somewhere in northern Utah, but with multiple moving parts several days out, it is difficult to put much confidence in any particular model run. This feature would also likely be quite narrow in width, making placement further difficult to pin down. All the same, it'll be something to keep an eye on as it would bring potential for another swath of locally higher rainfall amounts with a more prolonged period of moderate to heavy rain. As far as flooding is concerned, the highest threat will be over those typical rain sensitive basins such as slot canyons, typically dry washes, slickrock areas, and area burn scars. That said, even more urban areas where heavier rainfall can overwhelm drainage will be something to monitor, especially as area rivers and streams will see response from the rain/runoff (see hydrology section).

Uncertainty in the forecast increases quite a bit Tuesday and Wednesday. Models generally support the large trough deepening into the southwest CONUS, slowing its movement, and cutting off to an extent. While this occurs, per the NHC track, Tropical Storm Simon (expected to strengthen into a hurricane) is forecast to be moving northward along the Mexico coast or Gulf of California. Moisture with this tropical system may then once again lift into the slowly progressing trough, through the Desert southwest and into portions of the Intermountain West and Rockies. The exact track of Simon as well as the evolution of the deep trough will determine if or how much of the local area sees any impacts, or if moisture is shunted eastward. Models continue to have quite a bit of spread in those details, but certainly will be worth watching trends given the preceding impacts from Rachel, and likelihood of widespread saturated soils.

While in the extended range, there are some interesting model solutions towards the end of the work week, albeit with high uncertainty and model spread. As has been the case, it'll largely depend on the evolution of the large scale trough. In this case, if the cutoff trough can phase with another deepening northern stream trough, or if it'll just translate through overhead with minimal interaction. In the phasing scenario (favored more by GEFS members), a strong cold front moves through followed by quite a cold airmass. The deterministic GFS for example has 700 mb temperatures across the area falling to around -5C to -9C. The cutoff scenario (favored more by ECM ENS members) would have minimal thermal advection with it, and maintain more seasonable temperatures. Given the colder scenarios would carry some threat of overnight lows below freezing to portions of northern Utah, another area to monitor trends.

HYDROLOGY, Issued 1008 PM MDT Wed Oct 7 2026

With widespread precipitation of 1 to 2 inches, locally in excess of 3 inches between late Saturday and Tuesday morning, expect all area waterways including streams, rivers, normally dry washes, creeks, and slot canyons to have rising, fast flows by Sunday. Current forecasts do not bring any rivers to flood stage, but this will be monitored as the fine details of heavy rain bands become more confident. Those with interests near rivers, streams, creeks and recent burn scars should closely monitor the forecast over the next several days. Those with outdoor plans Sunday onward that include any travel near waterways across Utah should consider alternate plans.

AVIATION

KSLC...VFR conditions will prevail at the KSLC terminal through the TAF period. Light southerly winds remain in place before switching to diurnally-driven northwesterlies around 17Z. The southeasterlies will return around 3Z.

REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions will prevail across all regional terminals, with generally light diurnally-driven winds through the TAF period. Cumulus cloudS will continue to develop over the higher terrain through the overnight hours with some isolated showers and thundertorms. These storms could bring some gusty and erratic winds, lightning, and a brief mountain obscurations.

FIRE WEATHER, Issued 126 PM MDT Wed Oct 7 2026

After a dry and warm period, a Pacific system will combine with landfalling now Hurricane Rachel to bring a period of widespread moderate to heavy rainfall as early as Saturday evening, continuing into at least Tuesday morning. Some areas above 10,000 feet will see light snow accumulations, particularly Monday night into Tuesday morning. Additional precipitation may occur Tuesday into Wednesday...and potentially into the late week period depending on the speed of this Pacific system and the integration of additional tropical moisture from a second tropical system.

SLC WATCHES/WARNINGS/ADVISORIES

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