It has been a rough stretch across the Northwest lately with unseasonably warm temperatures and extensive flooding. This is about to change as a colder airmass takes hold, and snow totals over the next 5 days across the Cascades and BC Coast Range will range from 2-4+ feet.

Across the Canadian Interior and Northern U.S. Rockies, snowfall will range from 1-2 feet over the next 5 days, though warm air will be an issue at times from Southern Idaho to Western Wyoming. 

Northern Utah will see 6-12 inches on the southern fringe of this pattern, with only a few inches for Northern Colorado. 

Forecast for Wednesday (Dec 17):

A storm featuring a strong cold front will move from the Northwest across the Northern Rockies, bringing heavy snow and powerful winds to many areas, while Northern Utah and Northern Colorado will see lighter snowfall on the southern fringe of the system.

In the East, a weak disturbance will move across Northern New England with snow showers developing.

Forecast for Thursday (Dec 18):

Another strong storm will impact the Northwest, favoring Washington, British Columbia, Alberta, and Northern Idaho & Montana. Warmer air will lead to dense snow and rising snow levels (rain for some lower elevation terrain) from Oregon to Southern Idaho to Western Wyoming and Southwest Montana.

In the East, a much warmer airmass will take hold, and a rain event is expected from the Lower Midwest and all across the East from the Appalachians to New England. Snow will fall across the Northern Great Lakes into Ontario.

Forecast for Friday (Dec 19):

A storm will continue to impact the Northwest and the Northern Rockies, with the heaviest snowfall expected south of the border across Washington, Idaho, Montana, and Wyoming. Also, colder air will arrive in Oregon with heavy snow expected over the Cascades.

In the East, a cold front will arrive on the backside of Thursday's storm with a changeover to snow showers, favoring the western slopes of the Appalachians, Upstate New York, and Northern New England. Another storm will also reach the Northern Great Lakes on Friday night.

Forecast for Saturday (Dec 20):

Snow will linger across Southern Idaho, Southwest Montana, and Western Wyoming, with enough moisture sliding into Northern Utah and Northern Colorado for light snow to develop. Rain will also develop around Tahoe with snow levels near to above most ski resort summits. 

Another storm will also reach the Northwest with moderate to heavy snow developing across Washington, Oregon, Canada, and Northern Idaho/Montana.

In the East, a storm will move across the Northern Great Lakes before eventually reaching New England on Saturday night.

Forecast for Sunday (Dec 21):

Yet another storm will move across the Northwest and Northern Rockies with light to moderate snow for many areas. The heaviest precipitation is actually expected from Tahoe to Southern Idaho and the Tetons in Wyoming, but warm air will lead to mostly rain at Tahoe, and even Southern Idaho and Western Wyoming will see some rain issues.

In the East, a storm will swing across New York, New England, and Quebec with more widespread snow expected, though there are some storm track uncertainties per usual 5 days out.

Outlook for Mon (Dec 22) to Fri (Dec 26):

The pattern looks to remain similar overall heading into the holidays. A West Coast and Northwest-focused storm track will remain, but high pressure and abnormal warmth will persist across the Southern and Central Rockies.

The Northwest, Canada, and far Northern U.S. Rockies will be the most favored due to frequent snowfall expected along with colder temperatures and lower snow levels.

To the south, wet storms are expected from Tahoe to Southern Idaho and Western Wyoming, but warm temperatures and rain/snow level issues will persist here, especially in Tahoe. 

In the East, near to below-average temperatures are expected across New England with a better chance of snow with any storms that move through. Above-average warmth is expected to persist further south across the Mid-Atlantic and further west across the Great Lakes.

Thanks so much for reading! Next update on Friday (December 19).

Alan Smith 

NEW: PEAKS Model

Following 18 months of development, training, and testing, our new PEAKS model is now live and creating every snow and precipitation forecast in OpenSnow.

This is included with Free, Base, and Premium accounts for every snow and precipitation forecast in the OpenSnow app and website. No action is needed to view PEAKS and its forecasts.

What is PEAKS?

PEAKS is an AI (machine learning) model that is up to 50% more accurate in mountain terrain.

PEAKS learns from past storms and transforms normal weather models (used by other apps) into sharper, more location-specific forecasts. Learning from past storms is what human meteorologists do, but unlike humans, PEAKS can forecast for every location on earth with updates taking only seconds.

Bottom Line: OpenSnow has developed a world-first mountain forecast model that evaluates past storms to create more accurate predictions. This should provide you with higher confidence when searching for your favorite conditions.

Details → PEAKS FAQ