Pattern change ahead for the Western U.S.

Late last week, areas of the Four Corners region (CO/NM/Eastern Utah) along with the Pacific Northwest received high elevation snow. Other areas of the West have been enjoying their last stretch of mild/sunny weather and peak fall colors before big changes arrive later this week.

So far, the heavier snows have been confined to Alaska and Central/Northern British Columbia as is typical for this early in the season. However, we're going to see more significant snow pushing farther south into the U.S. ranges over the next couple of weeks.

During the next 7 days, a trough of low pressure will be the dominant pattern across the Western U.S., which will favor higher precipitation chances along with cooler temperatures. 

In fact, the upcoming week is looking wet across a good portion of North America, with the only exception being the Great Plains. Over the Eastern U.S., a slow-moving area of low pressure in the mid-south region will interact with Gulf of Mexico moisture to produce wet conditions across the Appalachians along with mild temperatures. 

Now, let's take a look at the snow forecast across North America over the next several days...

Forecast for Mon, Oct 4 – Wed, Oct 6

Monday will be the last quiet day across most of the West. On Tuesday and Wednesday, a storm system over the Pacific Northwest will bring heavy snow to the mountain ranges of Central British Columbia and lighter high elevation snow over the Cascades. 

Meanwhile, a storm system developing over the Southwest U.S. will result in widespread rain and high elevation snow across the Four Corners region. The Sierra Nevada Range could see some light snow higher up as well. 

Forecast for Thu, Oct 7 – Fri, Oct 8

A stronger storm system will impact the Sierra Nevada and Northern/Central Rockies on Thursday and Friday. Not only will this produce the first widespread snow around Tahoe, but it will also help out with the fire situation in the Sierra.

Colder air will gradually be working its way from west to east during this time with snow levels starting out relatively high across the Rockies on Thursday before gradually lowering by Friday. 

Farther north, heavy snow is expected across the coastal ranges of Northern British Columbia and Southeast Alaska.

Forecast for Sat, Oct 9

The late-week storm will move across the Rockies on Saturday with colder air and lowering snow levels. Snowfall looks to favor the mountain ranges of SW Montana, Wyoming, Utah, and Colorado. The higher elevations of California and Oregon could see some lingering snow early in the day.

Additional snow showers can be expected farther north in British Columbia and Alaska as well, with lighter amounts compared to previous days. 

Outlook for Sun, Oct 10 – Thu, Oct 14

Next week's pattern is looking very active across the West with multiple storms possible. A colder-than-average airmass is also projected to take hold, which will result in lower snow levels.

Snowfall next week will likely favor Western Canada, the Cascades, and the Northern/Central U.S. Rockies. However, the Sierra Nevada Range and Tahoe region could see some snow as well. 

Thanks so much for reading! Check back for my next post on Wednesday, October 6th.

ALAN SMITH