Big Picture:

A storm system will move across the West from Monday through Thursday (October 9-12) with valley rain and mountain snow favoring the Northwest and Northern/Central Rockies. The Sierra and the Southwest will largely miss out on this system as the storm will be taking a more northerly track.

Across the East, a cooler and drier pattern will prevail from Monday through Wednesday (9-11), though light showers will remain possible at times near the U.S./Canada border in the Northeast and across the Southern Appalachians from West Virginia to North Carolina. Heavier rain (and snow) can be expected on the north side of the Great Lakes across Ontario.

Forecast for Mon (Oct 9) to Tue (Oct 10):

Rain and snow will develop across the Northwest and Northern Rockies as a Pacific storm system makes landfall. Heavy snow can also be expected across the Coast Range of Southeast Alaska. 

Further south, moisture from the remnants of Tropical Storm Lidia in the Pacific will reach the Southwest with scattered light showers expected. This pattern could also result in light snow across the higher peaks of the Colorado Rockies. 

Across the East, a low pressure system over the Northern Great Lakes will result in rain just north of the border in Ontario and Quebec, and snow could mix in and possibly accumulate at times.

Forecast for Wed (Oct 11) to Thu (Oct 12):

The Western storm will slowly work its way inland with lingering rain and mountain snow over the Cascades and British Columbia. As the storm crosses the Rockies, moderate to heavy snow will be possible across the higher elevations in Southern Montana, Wyoming, Northern Utah, and Western Colorado. 

Forecast for Fri (Oct 13) to Sat (Oct 14):

The Western storm will begin to exit the Rockies out onto the plains on Friday with lingering snow showers possible east of the Divide in Wyoming and perhaps in Northern Colorado.

As the storm works its way across North America, rain will develop across the Great Lakes and Mid-Atlantic with most of the action expected to hold off across New England until later in the weekend.

The West Coast of the U.S. and British Columbia will see a brief break in the pattern though rain will be possible by Saturday PM as the next storm approaches. Alaska will also feel the effects of this storm on Friday and Saturday with heavy snow developing across the Coast Range. 

Outlook for Sun (Oct 15) to Thu (Oct 19):

The main storm track will favor the Pacific Northwest and Western Canada with significant rainfall possible. Above-average temperatures will result in high snow levels across this region. Most medium-range models are also hinting at a weaker storm sneaking across the Sierra and Central Rockies.

Below-average temperatures are expected across the East with wetter conditions also anticipated in the Northeast and New England. The higher peaks of the Whites and Adirondacks could potentially see snow mix in from time to time. 

Thanks so much for reading! Next update on Wednesday (October 11).

Alan Smith