textproduct: Salt Lake City

KEY MESSAGES, Issued 1034 PM MDT Fri Sep 25 2026

- It is increasingly likely that deep tropical moisture from Hurricane Odalys and/or Hurricane Polo will be drawn northward ahead of a strong disturbance Monday into Tuesday.

- A slight risk (level 2/4) for excessive rainfall has been issued by the Weather Prediction Center for southern Utah between 12Z Monday and 12Z Tuesday.

- This will bring an increased risk for flash flooding across national parks and recreation areas across southern through east-central Utah on Monday and potentially into Tuesday.

DISCUSSION, Issued 1034 PM MDT Fri Sep 25 2026

A weak shortwave ridge is building into Utah this evening ahead of a shortwave trough ejecting across the PacNW and Idaho, and as subtle low pressure over eastern Utah earlier today lifts northeast away from the area. Convection from earlier this afternoon has mostly waned, leaving patchy midlevel clouds. Meanwhile, the trough to the northwest will continue to eject into western Montana. This will push a cold front into northern Utah tonight, dropping temperatures a few degrees there through Saturday. The weather will be otherwise benign on Saturday, with drier and more stable conditions under a somewhat breezy southwest flow.

Models are still consistent in lifting a vort max originating near Hurricane Odalys through Utah on Sunday. This will bring increased moisture to the area, leading to isolated to widely scattered convection, mainly over the higher terrain. This will start priming the airmass for the next storm system Monday and Tuesday, which looks increasingly likely to tap tropical moisture.

Cluster analysis of global ensembles are coming together on the idea of the splitty solution with a closed low tracking across Arizona on Tuesday. Meanwhile, models are also favoring Hurricane Polo to cross into northwest Mexico Tuesday morning before its remnants move into New Mexico. The pattern favors tropical moisture being ingested into the southwesterlies ahead of the closed low, and model QPF has been increasing. However, the question is how much of this moisture makes it into Utah, given the southerly track of the low. While the bulk of the moisture will remain south and east of Utah, there are indications that portions of southern and southeast Utah will likely receive widespread precipitation and potentially significant amounts. The latest NBM has 25th percentile amounts Monday through Tuesday of a third to a half an inch across southern through southeast Utah, while the 75th percentile has widespread 1.25-1.5 inches with locally greater than 1.75 inches between St George and Kanab. Looking at it a different way, the southern third of Utah has roughly a 30-55% chance of exceeding 1 inch of rain between 12z Monday and 12z Wednesday. There is a Slight Risk for Excessive Rainfall in that area Monday morning through Monday night. Meanwhile, northern Utah currently has less than a 30% chance of seeing even 0.5 inches over the same period (except over mountains). Will continue to monitor developments to see if any hydro highlights are needed for southern Utah in the near future.

Cooler temperatures are expected areawide Monday through Tuesday, with afternoon maxes falling to 3-10 degrees below normal. Temperatures should rebound as the low exits the area Wednesday afternoon. However, there are uncertainties regarding the large- scale pattern for the latter half of the week, with ensembles split between another trough moving into the area and ridging or zonal flow patterns.

AVIATION

KSLC...The SLC terminal will see VFR conditions throughout the day with some high clouds. Northwest winds are expected to become light and variable or light southerly between 13Z and 15Z before returning to the northwest between 19Z and 21Z.

REST OF UTAH AND SOUTHWEST WYOMING...The airspace will see VFR conditions throughout the day with some high clouds. Generally light winds are expected through mid-morning before increasingly breezy southerly winds develop, particularly for western Utah.

FIRE WEATHER, Issued 443 AM MDT Sat Sep 26 2026

Conditions will stay dry across Utah today, but southerly winds will start to increase as a storm system makes its way toward the California coast. Winds will be occasionally breezy across western Utah this afternoon, and this will combine with pockets of minimum relative humidity values approaching 15 percent to bring areas of near critical fire weather conditions. Winds will increase further for Sunday, though the southerly flow will start to bring some moisture back northward. The storm system is expected to move across Utah during the day Monday, and it is looking increasingly likely that it will tap into some tropical moisture, bringing widespread coverage of showers and thunderstorms to the southeastern three-quarters of the state along with much cooler temperatures. A drying and warming trend is then expected to develop for much of the remainder of the upcoming week.

SLC WATCHES/WARNINGS/ADVISORIES

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