Low Tide

High cirrostratus clouds with a few lenticular-ish and mountain wave clouds out there this morning. The mountain wave and lenticular clouds are a sign that moderate to strong upper-level winds are interacting with the terrain in a similar manner as water in a river flows over boulders. 

Lenticular-ish clouds over the Wasatch 

If we check out the sounding from KSLC this morning, we can find strong winds 30+kts above 650 mb coincident with a moist stable layer - temperature profile is isothermal or inverted and temp/dew pt are close. Mountain waves and lenticular clouds form when air is forced upward, cools, and condensates within these types of stratified stable layers. Mountain wave clouds can be identified in satellite imagery by the ripples in the cloud field. 

GOES-18 West 12/10/2025

Left: KSLC 12Z 12/9/2025 sounding; Right: Simple schematic of how mountain wave clouds form (credit: theweatherprediction Habyhints)

When stable air is forced upward - due to underlying terrain - it becomes less buoyant than its environment. Less buoyant air will naturally accelerate in the negative vertical direction in an attempt to reach it's original equilibrium point. However, due to its downward momentum, it will initially pass its equilibrium point before correcting itself and accelerating back in the upward direction. The air mass will continue to oscillate in this upward/downward manner until it attains equilibrium. Conceptually, this phenomena is similar to how a spring oscillates when a force is enacted on it.

Short Range

Besides the interesting clouds over the Wasatch, not much is going on weather-wise today besides the abnormally warm temperatures. Highs in the northern Utah valleys will top out in the mid to upper 50s on Wednesday which is more like March than December. We can thank the placement of an upper-level ridge centered just off the U.S. Pacific coast for the warmth and relatively quiescent weather pattern. 

12Z 12/10/2025 analyzed 500 mb heights and temp with overlays

The upper-level ridge is forecasted to be stubborn and somewhat stationary over the next 5-7 days, shunting the storm track with the most energy and moisture around the northern periphery of the ridge and leaving areas to the south dry and warm. Currently, Utah sits on the downstream edge of this ridge but will become more firmly under it's grasp later this week into the weekend. This means moisture will be directed north of the state for the next few days to a week at least. 

Who is the winner with this setup? The PNW and northern Rockies win out in this scenario. They will be in the line of fire through the middle of December, with rounds of storms expected. 

ECMWF ENS 12Z 12/10/2025 Left: 7-day 500 mb height anomalies (m); Right: 7-day precipitation anomalies (in)

Long Range 

The bottom line?… the tap will be shut off for Utah the next 5-7 days, with warm and dry conditions expected. It may even get warm enough that daytime snow making becomes an issue at some of the ski resorts. This forecast is unfortunate, considering people just started feeling like the season was finally starting after this past weekend’s storm. 

ECMWF ENS 12Z 12/10/2025 forecasted Pacific North American Oscillation

The models are all over the place in terms of timing and intensity of the next potential storm that will hit the state. However, there are hints that the ridge will flatten or transition into a trough across western CONUS late next week or at least the later half of this month. Looking at the forecasted PNA (above), most models are suggesting that troughing across the western U.S. is likely after mid-December (negative PNA values). This would mean the Pacific would open up and a more active and wet weather pattern would be in store for Utah. I would take this information with a heavy spoonful of salt as models have been having a very difficult time beyond 3-5 days...