TL;DR; An exciting and cold weather pattern to move in mostly impacting
southern Utah and the four corners area followed by a series of storm systems
region-wide continuing through much of next week. Nowcast: The valley is met with cold overcast weather this morning with
temperatures down to freezing in the valley and 15 degrees Fahrenheit at the
top of Collins. South and southwesterly flow continues to dominate the forecast
area aloft carrying moist air.
As the upper level trough passing southern California and digs into Arizona it will form a cut off low carrying some trailing precipitation westward across northwest Nevada.
Short Term: Northwesterly flow behind the trough working with a saturated
air mass should create opportunity for orographic forcing resulting in light
snow this afternoon and evening with potential to last longer along the Wasatch.
Haze will remain possible through the day but cold pools in the valley should
ventilate by tonight. A short wave trough is moving through the building ridge
quickly digging to the southeast and affecting us Friday. With favorable
northwest and moist flow we will see enhanced orographic flow. While the valley
may only accumulate an inch, I am expecting up to 4 inches in along the upper
benches.
Totals at Alta-Collins could be anywhere from 4 to 20+ inches come Saturday
morning with the NAEFS plumes graph mean being just over 20 inches but the SREF
plumes graph mean calling for just under 5 inches. I am predicting things to
stay much closer to the lower end around 5-8 inches in the mountains with
potential for locally higher totals just sticking with the trend of the NAEFS
plumes being drastically high this season.
Long Term: The long term starts with a brief lull in the snowfall
Saturday but don't fret it looks like there is more storms on tap. Abundant
moisture and persistent cold temperatures along with an upper level trough
digging in from the PNW down to southern Nevada then moving eastward by Sunday
will bring lots of potential for snow. Although the strongest synoptic forcing
will be to the south, low level instability should make precipitation likely all
over Utah lingering into most of Monday.
Another break coming Tuesday with the some ridging bringing a period of subsidence and warm air advection from the west. The length of that will depend on how quickly the next trough moves in to cut this off but it is too far out to tell right now with not much agreement among ensemble members on the timing. Conditions are favorable and it seems likely this active pattern will lead beyond this, fingers crossed.
Backcountry Comment: Avalanche conditions are subject to change with incoming snow so be sure to stay up to date and know before you go with help from friends at
Utah Avalanche Center
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