2 additional significant storm systems are going to impact the Sierra in the next 72 hours with #1 just entering the northern mountains (Snowing heavily as of 6 AM). Cooling temperatures late week will provide a grand finale powder day for late Saturday and Sunday with significant lake level accumulations. The leftovers for both storms will favor the Wasatch and 4 corners before weakening as it moves over most of Colorado late this week. If your chasing powder, the deepest amounts will be in the Sierra followed by the isolated areas in Utah and northern Arizona.
Heres a shot from Grand Targhee from yesterday where 9-11 inches fell overnight Tuesday. Photo: Matt Baydala
Heavy snow will be falling in the Sierra through Thursday night. Intensities decrease on Friday morning, however, snow showers are likely to still be falling as you start to dig out. Epic amounts of medium to dense snow (Elevation dependant) will approach 50 inches at mountaintop levels (Mammoth is favored for the highest amounts), and generally 18-30 inches at most ski areas.
I would not be surprised if some ski areas report 4-7 foot drifts at the summits. A brief break in the action Friday will lead to another significant round of snow this weekend. Colder temperatures and high-quality snowfall will be falling again in the Sierra late Friday night into Saturday. The snorkel alert is for dry density pow friday night/Saturday.
This will bring a quicker shot of snowfall that may allow for some clearing skies on Sunday. Expect 9-14 inches of additional snow including Lake Level by late Saturday. This week is a game-changing event for most ski areas in California! By next week, you will see most resorts in nearly full operation with rope drops happening slowly as avalanche mitigation takes place. The best news is that each storm has been progressively colder and \"Right Side Up\" snow is an added bonus to the snowpack. Significant Avalanche danger will exist with strong winds and medium to medium dense snowfall, especially with the current storm system. 7-day storm totals (Includes the last system) may exceed 70 inches at some resorts by Sunday.
Below: Heavy moisture entering most of the Sierra today with a cold front (Blue line) to the north that drops down Friday night/Saturday. Image: Meteostar
The rest of the west? I've been pondering chases. The bulk of moisture is going to drag across Nevada and Arizona late Thursday. Arizona will nab a foot or more of pow near Flagstaff. If they were open and in full operation I would be chasing there right now!
Moisture will be streaming into southern Utah that will push snowfall into the Wasatch. I am bullish for the Wasatch who often reaps rewards from moist Sierra storms that tend to weaken significantly as they head inland. We are working with leftover moisture versus deep orographics that can occur with cold temperatures and terrain favored forcing. Up to 8 inches has fallen at resorts favored by SW flow in Utah as of press time of this post (Brighton and Solitude takes the win). If you're jonesing for pow head up this morning! SW flow will continue light snow showers today before winds shift westerly Thursday night. There will be an uptick of moisture late Thursday through Friday morning. Winds will gradually veer to the NW which may enhance snowfall in many areas with better snow ratios (Colder temperatures). There is no single double-digit event in a 6-8 hour window, however by late Friday most resorts will be looking at several inches of new snow. Some favored locations in the Cottonwoods may see 8-14 inches by late Friday. After a brief break late day, another push of moisture under NW flow will kick off some additional dry density pow for Saturday morning. Ride times will be Friday (Storm ski) and early Saturday (Colder with better densities and additional moderate amounts). Both Friday and Saturday will offer good turning conditions.
Moisture pushes as far north as the Tetons late Friday and Saturday with 4-8 inches possible in these areas. Significant wrap around moisture will be occurring in central and eastern Montana and Wyoming that may land significant snow to the interior away from most ski areas.
In Colorado, the chases will be trickier. SW flow on Friday will squeeze leftover moisture from the Wasatch that aims for the 4 corners. Purgatory, Telluride, and perhaps Silverton are favored followed by a Wolf Creek wildcard. Crested Butte will also be in the mix. The wind direction (SW) is optimal for the Wolf, but most of the moisture may get squeezed out further west. Moisture will also be streaming due north towards Steamboat that should see 3-5 inches during the day. My best guess is 4-8 inches during the day Friday for many of these areas. Winds shift to the West late Friday that will increase snowfall for most of Colorado's northern and central mountains. The wind shift late Friday/Saturday should land 5-10 inches favoring resorts on the western side of the State. Solid contenders are Beaver Creek, Steamboat, Snowmass, Crested Butte (Wildcard), and Monarch. Winds may shift to the NW by early Saturday so Vail and resorts in Summit County will also be seeing snowfall (Lower amounts). My confidence in this forecast is 65/35 (35% chance of more or less snow). If your chasing pow aim for the south Friday and the north on Saturday. You may find the highest amounts on the western side of the mountain ranges. Watch the webcams on Friday and early Saturday morning.
Honorable Mention: The Pacific Northwest is going to see a decent shot of cold air and snowfall late this week. The bulk of moisture is likely to impact central and southern Oregon. Mount Bachelor would be a good wildcard bet for Friday/Saturday. Its possible 9-14 inches fall through Saturday morning with colder temperatures.
Below: You can see the highlights snowfall totals through Saturday mid-morning for many areas of the west. Notable winners in the Sierra, southern Oregon, Utah, and the 4 corners.