textproduct: Salt Lake City

KEY MESSAGES, Issued 1032 PM MDT Tue Sep 1 2026

- The drying trend over Utah and southwest Wyoming will continue through Friday with conditions staying breezy, particularly over western Utah. Though recent rain has caused improvement in fuels, locally critical fire weather conditions remain possible. - A surge of tropical moisture associated with Tropical Storm Marie is expected to move into the area from the south over the weekend, persisting into early next week. This will bring increasing coverage of showers and thunderstorms capable of producing heavy rain that could lead to flash flooding.

DISCUSSION, Issued 1032 PM MDT Tue Sep 1 2026

A low pressure system is moving onshore along the northern California coast this evening. The proximity of the system to Utah and southwest Wyoming has brought a noticeable increase in southwest flow aloft that is drawing drier air into the area. Coverage of showers and thunderstorms today was significantly more isolated than the past few days, with just a few showers lingering over far northern Utah at this time. Temperatures today were up to 5F below seasonal normals across the area.

The California trough is expected to move over the broad ridge centered over the central United States tonight into Wednesday, with a stronger Pacific Northwest system quickly taking its place off the coast by Wednesday evening. This will keep the area breezy, with a few gusts in excess of 40 mph possible during the afternoon. However, latest guidance indicates a low chance at best of these gusts being widespread enough or persistent enough to warrant headlines. Though pockets of relative humidity values below critical levels are expected to develop over western Utah this afternoon, the limited coverage combined with improvement in fuels from recent rains also limits the need for fire weather headlines.

The continued advection of drier air into the area will limit afternoon convection to the higher terrain over eastern Utah on Wednesday. Convection is expected to be suppressed across the area Thursday into Friday with dry air moving in more aggressively. Little change in temperatures is expected during this period, with highs remaining just below normal for this time of year.

The Pacific Northwest trough is expected to move little through the upcoming weekend, keeping breezy southwest flow in place. Some guidance indicates the trough making a closer approach on Friday, which has a decent chance of bringing up winds enough that an advisory might be necessary. Thereafter, attention turns to what is now Tropical Storm Marie in the eastern Pacific. Over the weekend, guidance seems to be becoming increasingly confident that the continued westward movement of the system will allow the persistent southwest flow to tap into the deep moisture from this system and draw it northward into Utah and southwest Wyoming. This has the potential to bring precipitable water values near record levels for this time of year, bringing widespread precipitation and an increased potential for flash flooding. However, the timing of the arrival of the moisture and the details about which areas will see the most moisture are relatively low confidence given that they are highly dependent on the track of Marie. It is also worth noting that in some of the previous cases of moisture from a tropical system advecting into the forecast area, the resultant cloud cover was an inhibitor to precipitation, resulting in a more stratiform rain type of event. Regardless, this is a relatively rare setup for the area and it will be interesting to see how things evolve through early next week.

AVIATION

KSLC...Southerly winds will persist, with occasional gusts to 20- 25kts overnight. Peak wind gusts are expected between 15-21z before lightening up and becoming more southwesterly. A weak front will then produce a northwesterly wind shift around 23-00z. VFR conditions will prevail.

REST OF UTAH AND SOUTHWEST WYOMING...Southerly winds will continue across most sites, with gusts to 25-35kts developing after 15z. A weak, shallow front will push through northern Utah by late afternoon, but will struggle to push south of KSLC. This front will bring lighter, northwesterly winds temporarily...before southerly winds pick up again by 06z Thursday.

SLC WATCHES/WARNINGS/ADVISORIES

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