Big Picture:

The seasons are changing across North America! From a mountain weather and outdoors perspective, there are four key weather patterns of interest right now.

1) Snow for the Higher Peaks of the Rockies: A slow-moving storm system moving across the West Central U.S. will bring high-elevation snow to Colorado, Wyoming, and Utah from Wednesday to Saturday, while the High Sierra in California will see some light snow as well. Low to mid-elevation areas will see rain showers and thunderstorms.

2) Cooler Temperatures ahead for the East: A cold front will move across the Eastern U.S. on Wednesday, ushering in the first stretch of fall-like temperatures, which will last through the weekend. 

3) Hurricane Lee Impacts Possible in New England & SE Canada: A hurricane in the Atlantic is projected to move northward and potentially make landfall in SE Canada on Saturday (likely as a post-tropical cyclone). While the exact track of the storm is still uncertain this far out, impacts are possible in parts of Eastern New England (especially Maine) and SE Canada, including heavy rain and coastal flooding. 

4) Heavy Snow for the Alaska Coast Range: A series of storms will impact the Coast Range of Alaska over the next several days, resulting in heavy snow across the higher elevations. Snow levels are generally expected to range from 3,000-4,000 feet.

Check out our 5-day snow forecast for South Central Alaska, courtesy of the OpenSnow Powder Finder.

 

Forecast for Wed (Sep 13) to Thu (Sep 14):

A slow-moving trough of low pressure moving across the West Central U.S. will result in high-elevation snow across Colorado and Wyoming with showers and thunderstorms expected for the lower elevations of the Rockies as well as the Southwest. Isolated flash flooding is possible in slot canyons and dry washes in the Southwest.

Further north, heavy snow can be expected above 3,000-4,000 feet across the Alaska Coast Range.

Across the East, a cold front moving through will result in widespread showers and thunderstorms favoring the Mid-Atlantic and New England. Wednesday will be the wetter of the two days, with a drying trend from SW to NE on Thursday.

Forecast for Fri (Sep 15) to Sat (Sep 16):

An unsettled pattern will persist across the West with low/mid-elevation rain showers and high-elevation snow showers expected across the Colorado Rockies, while the High Sierra in CA and the Uinta Range in UT should pick up some snow as well. Heavy snow will continue to fall further north across the Alaska Coast Range.

Hurricane Lee is expected to impact portions of SE Canada and possibly Eastern New England during this period. While the exact track and geographic coverage of impacts are still uncertain, heavy rain and strong winds are a possibility across Nova Scotia, New Brunswick, and Maine. The rest of New England looks to be right on the edge. 

Forecast for Sun (Sep 17) to Mon (Sep 18):

Conditions will start to dry out across the West Central U.S. during this period, but we could still see some lingering isolated showers across the Southern Rockies and Sierra, including flurries over the higher peaks. 

A storm system will also impact Canada during this period, with the focus of heavy snow shifting from Alaska into the higher terrain of Northern BC. Across Southern BC, rain can be expected for the low/mid elevations with light snow for the higher elevations.

A system will also bring rain to parts of the Midwest and East during this period, with lingering rainfall from Lee also possible across parts of SE Canada and New England. 

Outlook for Tue (Sep 19) to Sat (Sep 23):

The West is looking more unsettled during this period. Longer-range models are hinting at a storm system arriving that could result in cooler temperatures and snow for the higher elevations of the Rockies. However, confidence in the details is low at this time.

An active storm track is expected to continue across Alaska with more snow likely for the Coast Range.

A drier pattern is expected across the East along with near-average temperatures, which should make for enjoyable early fall conditions. 

Thanks so much for reading! Next update on Wednesday, September 20th.

Alan Smith 

In case you missed it, we launched the South America Daily Snow this year during the Southern Hemisphere winter. The Andes have been getting dumped on recently, so be sure to check out the latest forecast in case you are yearning for some winter stoke after a long summer.