Powder Alert! Atmospheric River Approaching The West

Report from Powderchasers.com

The week ahead will be very active with our focus on the Sierra Range Thursday/Friday and the Rockies Friday-Saturday. The models are still in flux with how much snow pushes north into Wyoming and Montana, with a hopeful trend. The 4 corners and Sierra will likely be the wettest, with some decent snow totals also noted for isolated spots in Idaho, Wasatch Range, and Colorado.

As of 5 AM Monday telemetry is showing 6 inches at Alyeska since the lifts closed on Sunday. Temps are near 0 at mid-mountain and 6F in Girdwood. Snow will continue through the morning with storm totals expected to be in the 5-10 inch range (Downtrend from Sunday’s forecast). Conditions will be epic aside from the ultra-low density sink to the bottom surface. Backcountry might also be a great option if you have the proper skills. More significant snow was falling towards Thompson Pass and Juneau (10-20) near Alaska Backcountry Guides.

ANNOUNCEMENT: Alaska is on the top list of annual snowfall this season. Powderchasers has been partnering with Alaska Backcountry Guides for many seasons located in Valdez. They have fantastic coverage currently and only limited seats open. The open 2 seats at the end of February include unlimited vertical! Any bookings with ABG will provide you a free mid level Concierge with Powderchasers good for this or next season. Mention PC when calling. Grab these seats before they are gone here.

In New England, Windham Ski Area in New York picked up 8 inches. Other reports from New England are below. Snow will be dense!

Gunstock- 6 inches
Okemo-7 inches
Pats Peak-7 inches
Mt Snow-6 inches
Berkshire East- 6 inches

There is not much else to discuss in the short term as very warm conditions overspread the west.

Rain is going to be falling this week in the Pacific Northwest primarily on the western side of the Cascade Ranges.

Cooling will occur on the backside of the upcoming AR later this week. The key to chasing powder is to grab this colder event. Winds will be an issue before the front in CA on Wednesday decreasing on Thursday with a deep opening.

Late week storm:

Models are on the uptick on Monday morning with moisture totals for the Sierra. The models are still in poor agreement for how much snow will creep north into the central and northern Rockies. The 4 corners are highlighted with over an inch of moisture noted for southern Utah, Colorado, and perhaps northern Arizona with New Mexico wildcards. The good news is that the American Model which previously showed little to no snow for areas north of central Utah has come a bit more in line with the European and Canadian that have been consistent in advertising a decent push north. This is good news for many ski areas.

Main Points

* Sierra will grab 12-18 inches above 8,000 feet from Thursday to Friday. This will be a warm storm followed by cooling as moisture decreases on Friday. Ride higher elevations. Moisture totals are as high as 2.5-3 inches depending on which model you want to believe. Much lower totals will be reported at the bases. Winds will be cranking Wednesday to very early Thursday (Decreasing by opening). Wednesday will be a no-go for upper lifts. Some summits might see an excess of 20 inches above 9500 feet by Thursday night. Storm ski on Thursday and catch openings on Friday that could be deep (Surf with some lighter-density frosting). Sierra Crest will be deep with less snow on the eastern side.

* Storm transitions over the 4 corners Friday (Storm ski) with some push north into the Wasatch and perhaps the Tetons. Southerly flow over Idaho will likely funnel decent snow totals to the mid and upper elevations of Sun Valley. Models are in flux with some showing high totals for the northern Rockies while others keep the focus south. NW flow on the backside of the low Friday could sneak up a surprise for the Cottonwoods.

Below: U of U ensembles for Kirkwood showing an average of 20 inches by Friday morning. Some lines are higher but normally with this data plus the warmer temps, we might edge a bit conservative with 12-18 by Friday morning.

Below: Warm temps at 10K for California with a typical AR event (Warm and wet) noted Thursday (Storm ski). Cooler air will reach this region later Thursday evening with some additional better quality, but moisture is on the decrease. Map is at 10K with -4 to -6C temps. Cooling for Friday.

Below: American GFS depicting some heavy snowfall likely for Sun Valley Mid to upper elevations late Thursday to Friday. This model shows lighter amounts for the Tetons and Montana, however the European is more bullish!

Below: American Model (The pessimist on how far north moisture travels) a bit more bullish than previous runs for moisture to reach the Tetons and even southern Montana. The focus will be areas of southern Idaho, Wasatch, and the 4 corners. This model has also been consistent in bringing upslope flow to the eastern areas of Colorado that could land signficant snowfall at upper elevations outside of metro areas. Northern Colorado and the I-70 corridor would see less snow with the focus in the south including New Mexico resorts.

Below: The European model has been holding steady for decent totals extending north to the Tetons, Montana northern Colorado. This would result in less snow for New Mexico resorts but still shows good totals for southern Idaho and most of the 4 corners. Much less snow is noted for the Front Range Foothills. The Canadian models has also consistently shown this solution which leads us to believe the American might be a bit of an outlier right now. Steamboat can score in this pattern with S, SW flow pushing moisture north into the Flat Tops. Less snow is noted on the eastern I-70 corridor.

Below: Here are the water totals for the west through February 7th with most occurring in this late week storm. Pretty impressive totals for the Sierra (Additional precipitation falls next Tuesday) and some spots of the Rockies. AR events are great for water, but often not great for expecting blower. We need another base build.

Bottom Line: Very wet storm. Decent snow totals for the Sierra that could over perform (12-25 inches) Lots of uncertainty on how far north precipitation will fall with a focus in the southern regions of the Rockies. Lots of confidence for the Wood River Valley in Idaho, a bit less confidence on the Tetons, with strong contenders likely in Arizona, Utah, southern Colorado. Outside chance of decent totals for southern Montana resorts. Colorado could do well in the south with moderate totals elsewhere. Steamboat might over perform with SW flow on the western side of I-70. Crested butte, Silverton, Purg, and Wolf are all solid contenders. Taos is a wildcard.

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Enjoy the powder, everyone! Remember, your deepest resort is not always the best chase. See you in the first chair somewhere on Monday.

Enjoy the powder, everyone!

Powderchaser Steve @powderchasersteve on Instagram