The Winds of Change

A beautiful warm fall day with crystalline blue skies is expected for Thursday. Winds should be a bit breezy out of the south this afternoon with highs near 80 F for most Wasatch Front valley areas. Go take a look at the fall colors in the mountains before they disappear. Starting tomorrow - Friday - weather conditions will begin to deteriorate as our most potent storm in some months will impact Utah. 

An approaching upper-level low swirls just off the NW U.S Pacific coast on 10/2/2025, with clear skies across Utah

Left: 10/2/2025 16Z 500 mb gph, winds, and temperature: Right: ECMWF10/2/2025 max surface temperature

As of today, a bullseye low swirls just off the NW U.S Pacific coast, with Utah still under protective edge of a dome of high pressure. Utah weather will remain relatively quiet through Thursday, but Friday winds will increase out of the south ahead of the approaching low/trough, marking the beginning of change. Southerly winds will increase Friday morning through the afternoon as the storm/trough moves east across the Great Basin. There is a marginal potential for some blowing dust being generated across the central Utah deserts as winds look to gust 45-50 mph Friday afternoon. Whether or not dust gets generated or makes it up to the Wasatch Front tomorrow is still up in the "air". However, we will see some gusty southerly winds in the SL Valley. Additionally, a few high based showers or thunderstorms are possible Friday afternoon, which could also generate some gusty winds themselves. 

ECMWF 00Z 10/2 forecast for 10/4/2025 @ 00Z: (left to right) 500 mb gph, vorticity, and winds; Surface wind gusts (mph) 

By Friday evening/night, the main act will begin. The trough and cold front looks to move over Utah Friday night into Saturday, shifting winds more W-NW and bringing increased rain shower and storm activity. The most consistent precipitation along the Wasatch Front is expected as winds shift W-NW Saturday late morning to early afternoon, particularly in the mountains. As colder air moves in along the Wasatch Front on Saturday, daytime valley highs will only top out in the 50s and snow is forecasted for upper elevations in the mountains across the state (> 8000'). The Uintas look to be the winner in terms of potential for most snowfall accumulation, so for those with plans to go for a last minute leaf peep be very warry. For anyone that has been itching for prototypical fall conditions to get in the spirit of the spooky season, the cool and wet conditions on Saturday may fit the bill. 

ECMWF 00Z 10/2 forecast for 10/5/2025 @ 00Z:  (left to right) Total precipitation (in); Total snowfall (10:1 inches)

GFS 12Z Alta total snow accumulation plume

The system quickly moves east of the state by Sunday. However, a reinforcing shot of cooler air dives down south into the state behind the system, keeping things a bit unsettled. The combination of cooler upper-level temperatures and residual moisture could spawn a spotty shower or two on Sunday, particularly over the higher terrain in afternoon. 

ECMWF 00Z 10/2 forecast for 10/5/2025 @ 00Z:  (left to right) 500 mb gph, vorticity, and winds; 700 mb gph, winds, RH, and temperature

Beyond Sunday, the weather next workweek looks interesting but is layered with levels of uncertainty. Lingering cool air and a stalled frontal boundary across central Utah will keep things cool and may facilitate some periods of shower activity through early next week. A brief respite is possible between systems mid next week before a number of possible scenarios play out. 

As of now, there are hints of Utah being impacted late next week from the remnants of a tropical system from the eastern Pacific. There is plenty of uncertainty associated with this forecast, but it does seem as if models are trending towards bringing the extra-tropical system into the Desert SW. If this scenario plays out, a broad area of relatively heavy rainfall could impact the entire state of Utah, posing a risk for flooding in some areas. Nevertheless, this scenario is still out in the forecast fantasy land and details will most certainly change going forward. But is still something interesting on the radar... 

ECMWF 00Z 10/2 forecast for 10/6/2025 @ 06Z: MSLP, 1000-500 mb thickness, and 6-hr precipitation

A brief overview of sensible weather conditions this weekend through next week. Obviously this forecast should be taken with a heavy grain of salt, specifically once you get 3-5 days out from now (10/2). Either way, it looks like the last bit of 80 degree days for the year will be today and tomorrow. It will be a long shot if we warm back up enough to hit 80 in the next 7-10 days, but not totally out of the question.

ECMWF 00Z 10/2 forecasted surface summary overview