Finally, after weeks of high pressure and only minor, fast-moving cold fronts an actual storm system is lined-up.
It hits ID on 2/14, 2/15 WY/MT/UT, and 2/16 CO, NM.
This storm system is not a blockbuster, but it will pave the way for another storm system on 2/21-2/22.
Unfortunately, this storm system only brushes CA with light accumulation.
I did some backcountry skiing on Saturday in Colorado. Temps started below zero there was a couple inches of fresh snow. That’s been the pattern for the last 5 weeks with only fast-moving, minor cold fronts.
Here’s my full video forecast:
I include four snow forecasts in the video. Here’s one for the West from 2/13-2/20 taking into account this week’s storm system.
Abnormally dry pattern across the West with large high pressure dome through 2/13.
One minor, fast-moving cold front races through MT, WY, and CO between 2/10-2/11.
3-day break in precipitation for the Pacific Northwest and British Columbia this weekend as storm track shifts north.
Two Alberta Clippers deliver light snow accumulation to the Northeast through 2/13.
Snow returns to the Intermountain West around 2/14-2/15, but it appears to be a “one and done” setup.
Water vapor satellite shows the storm track and large Western high pressure ridge. Orange/red colors = drier air aloft.
The long dry stretch continues across CA, NV, and UT. Cold fronts are forced down the eastern periphery of the ridge through MT, WY, CO, and NM. This is what you might expect during a La Nina phase with some exceptions of course. The latest forecast keeps La Nina in place through Winter then gradually transitions to a “neutral phase” late Spring and early Summer. In the forecast below, negative (colder) anomalies = La Nina.
A brief drop in pressures arrive 2/14-2/15, but it’s appears to be a “one and done” setup. High pressure rebuilds through 2/20.
What occurs after 2/20?
The Pacific North American Pattern (PNA) stays lightly negative through 2/24. This suggests an active pattern across the Intermountain West can’t be ruled out. But, it’s not a strong signal.
Large Western high pressure blocks all major storm systems from CA, NV, WY, CO, NM through 2/14. Only minor cold fronts race down the eastern periphery through MT, WY, CO, NM.
Zero snowfall in CA, NV, UT through 2/14.
Pattern could turn more active after 2/14, but genuine pattern change might hold off until 2/18 or later.
I did some backcountry skiing on Saturday. It was windy, cold, and dry. Colorado’s snowpack has flatlined in the last 30 days with only minor amounts of new snow. SWE percentages have declined about 20%.
Infrared satellite shows the storm track and large Western high pressure dome. Only minor, fast-moving cold fronts will pierce the eastern periphery of the high pressure dome.
Western High Pressure: What’s Next?
The pattern turns more active after 2/14 but genuine pattern change might hold off until 2/18 or later. The forecast below suggests a significant drop in pressures across the West on 2/18. If this occurs then the jet stream would support a colder, snowier pattern.
The Pacific North American Pattern (PNA) agrees. The Euro flips the pattern negative after the 14th. The signal is even stronger after the 18th.
A negative PNA tends to correlate with a more active pattern across the West.