Persistence

TLDR; Clear skies will prevail with temperatures staying 5-10 degrees F below average for this time of year. A weak, moisture-starved shortwave trough will move through the region at the end of the work week with very little precipitation potential.

Nowcast

At the two open resorts in Big Cottonwood Canyon, temperatures are in the low 20s at lower elevations (~8000ft) and mid-teens at upper elevations (~9500-10,000ft). Skies are a deep blue this morning with hardly a cloud in sight over the Central Wasatch. Winds are calm to 10mph at the highest elevations. A dark goggle lens and plenty of sunscreen should definitely be on hand for those heading up to the mountains today. Enjoy the sun! 

Cloud-free skies prevail over northern Utah this morning, as seen from the NASA GOES-EAST satellite. Image courtesy of the College of DuPage.

Short Term

Not much in the way of significant changes to our weather over the next 36 hours as we remain in between a region of high pressure in the Gulf of Alaska and low pressure over the Eastern US. We will see gradual warming tomorrow in the range of 2-4 degrees F before cooler weather arrives Friday morning. A weak shortwave trough (a relatively small region of low pressure, a weak wave pattern that moves around larger scale features) will be moving through the region Friday morning cooling temperatures ~10 degrees F and increasing cloud cover. In the image below, the axis (center) of the trough at 5am MST November 18 is drawn in red.

500mb (~5500m above sea level) Geopotential Heights and Wind Barbs from GFS Model, Valid 5am MST November 18. Image courtesy of Tropical Tidbits.

The two crucial ingredients to produce precipitation for significant winter precipitation are dynamics and moisture. Simplified, dynamics can just be interpreted as upward motion in the atmosphere. Without significant upward motion, it is difficult to condense water vapor into clouds. This storm lacks both significant dynamics and moisture; Any precipitation with this event will likely amount to little more than a trace and will be confined to the highest elevations.

As some of you may have noticed, even with our notable dearth of precipitation in the last week, temperatures have remained below average. Why could this be? One key to this lasting cold is the origin of our current airmass. Let's take a look.

NOAA Hysplit Ensemble, 72hr Backward Trajectory Valid 5pm MST November 14, 2022. Image courtesy of NOAA Air Resources Laboratory.

The above plot takes the airmass that was located 500m above the surface at Alta and runs the model in reverse for 72 hours to see where it likely came from. The different lines are different possible solutions from different models in the ensemble. As you can see, the majority of the solutions are showing our airmass' origin to be interior Canada, dropping down from the North. Air from interior Canada this time of year is typically much cooler than our usual air masses in Northern Utah during periods of high pressure, as is the case here. 

Long Term

While we will likely remain dry for the next week, there is the potential for precipitation to make its return to Northern Utah in the 8-14 day outlook. The Climate Prediction Center is forecasting an elevated chance of above-average precipitation for our region. While this is by no means a certainty, it does mean the dice are loaded in our favor for the November 23 - 29 period.