| High cirrus shielding the morning sun |
Unfortunately, the high cirrus across northern Utah this morning are indeed a sign of change. A broad long-wave trough is currently making landfall off the Pacific into the interior of the PNW. The trough is associated with a mid-intensity AR, bringing heavy rain and mountain snow to the northern Sierras up through British Colombia. Some of this moisture and energy is forecasted to progress over the Intermountain West and into northern Utah come late Wednesday night into early Thursday morning. However, not expecting much as this weak system clips Utah overnight.
A cold front along with some showers will move into northern Utah come the second half of Wednesday night. The Wasatch Front valley areas could see a few light rain showers the during this time up until the morning commute, mainly focused towards the ID/UT border where better dynamics and moisture will reside. Areas south towards the SLV and Utah County will miss out on the 'bulk' of the moisture. All models are fairly consistent that total liquid amounts will be light, with the 50th percentile ensemble ECMWF and GFS forecasting 0.1-0.2" for the far northern Utah valleys and mountains. Otherwise, I would be impressed if areas like the SLV get enough precip to even fully wet the ground.
| ECMWF Ensemble 00Z 11/5/2025 : Total precipitation (in) at Alta, UT |
Thursday will be 10-15 degrees cooler than the unseasonably warm temps today (Wednesday), but will actually be near normal for this time of year. Dry air and a short-wave ridge will bring a mix of clouds and sun to Utah Thursday morning into the afternoon. A trailing short-wave trough and attendant moisture will move into the northern tier of the State come late Thursday into Friday, but impacts will be minimal to nil. Likely just bringing some cloud cover and keeping temps similar to Thursday. Beyond this workweek, things look to gradually warm back up over the weekend into early next week as a fairly amplified ridge sets over Utah.
Long-range
Typically, this time of year when attempting to gauge what the longer range weather has in store we like to look at the forecasted trends of certain climate oscillations or teleconnections. The most common climate oscillation or teleconnection that people are familiar with is ENSO (El Nino Southern Oscillation). However, as much as the news and skiers alike love to talk about El Nino/La Nina and what that means for Utah's winters, the ENSO impact/signal for northern Utah is weak or even can be considered indeterminant. If you were to really try and parse out any ENSO trends across northern Utah, there is a weak positive snowfall anomaly signal during La Nina years for the Wasatch. But even this isn't that meaningful and shouldn't be read into. On average, there's about a 50/50 chance that the Wasatch will have a wetter/drier winter during both El Nino or La Nina.
For the reasons above, ENSO is not the best teleconnection to analyze when attempting to conduct seasonal or even monthly long-range forecasts for northern Utah. Other oscillations such as the Pacific North American (PNA) oscillation are much more influential and impactful for Utah weather due to the synoptic pattern they describe and relatively shorter timescale of influence. The PNA describes the large scale upper-level pattern across the eastern Pacific/western North America. When the PNA has a negative signal that represents troughing across western North America and vis versa for a positive PNA signal. Troughing across western North America indicates a pattern that is conducive for bringing storm tracks down from the Gulf of Alaska/western Canada into Utah. Therefore, a negative PNA can indicate an active storm pattern across the western CONUS.
| ECMWF 12Z 11/5/2025 forecasted PNA signal |
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