Milder temperatures and significant moisture on the way for the West

Following an intense cold snap, milder temperatures will arrive over the holiday weekend as a strong west-to-east oriented jet stream sets up over the West and transports significant moisture along with warmer temperatures into the Cascades, Sierra, and Rockies.

Heavy snow will be possible throughout the West over the next 7 days, though the maritime ranges will see some rain, freezing rain, and snow level issues initially.

Forecast for Fri, Dec 23 – Sat, Dec 24:

A storm will impact the Pacific Northwest on Friday and Saturday with snow initially changing over to freezing rain across the Cascades and eventually all-rain for most areas on Saturday. Northern Idaho and most of British Columbia will stay all-snow through Saturday with deep totals likely across BC in particular. 

An arctic cold front will sweep across the Eastern U.S. on Friday with rain changing to snow showers behind the front. Heavy snow will favor the lake effect regions with lighter snow elsewhere. Otherwise, bitterly cold temperatures can be expected throughout the East and Midwest.

Forecast for Sun, Dec 25 – Mon, Dec 26:

Another storm will impact the Northwest during this period with warmer air resulting in mostly rain for ski resorts in Washington/Oregon, while interior northwest areas will see a mix of rain, freezing rain, and snow. The Interior of BC as well as Northern BC will see moderate to heavy snow. Light snow will reach areas further east and south in the U.S. Rockies.

Across the East, the lake effect snow machine will continue to roll with deep accumulations expected around the Buffalo area in particular. Elsewhere, lighter snow showers are expected along with frigid temperatures.

Forecast for Tue, Dec 27 – Wed, Dec 28:

A strong storm will impact the West during this period with heavy snow possible across most major ski regions. The Sierra will see relatively high snow levels given the mild air in place, while the Cascades will also see a mix of rain and snow, though snow levels will be trending lower compared to the last storm. The Rockies will be the best bet for significant snowfall without rain issues.

A weak storm could bring some light snow showers to portions of the East, while locally heavier lake effect snow showers will remain possible. Temperatures will also begin to moderate across the East during this period.

Outlook for Thu, Dec 29 – Mon, Jan 2:

The pattern is looking quite favorable out West during this period with frequent storms expected along with a gradual cooling trend, which should result in lower snow levels and more snow than rain for the Sierra and Cascades. The Sierra and Central Rockies will be the most favored in this pattern, but more northerly areas should also get in on the action.

Across the East, a substantial pattern change is expected with a transition from a cold/dry pattern to a warm/wet pattern with frequent periods of rain. 

Thanks so much for reading and Happy Holidays! Next update on Monday (Dec 26).

ALAN SMITH