Another Drenching For The Pacific Northwest, Heavy Snow Headed For Northeast

It’s been a remarkably quiet Thanksgiving across most of the United States. There are no severe thunderstorms to worry about. No massive nor’easters threatening to disrupt every major hub on the East Coast. The tropics are blissfully quiet. The only worrisome weather this holiday weekend seems confined to the two northern corners of the country, with another atmospheric river in the Pacific Northwest and heavy snow in interior New England.

Yet another atmospheric river has its sights set on the Pacific Northwest over the next couple of days. It’s already raining over much of western Washington and southwestern British Columbia, and there’s plenty more on the way over the next couple of days.

We’ve heard a lot about “atmospheric rivers” lately. An atmospheric river is an area of elevated moisture in the upper atmosphere that usually flows from the tropics to the mid-latitudes. These features act like reservoirs that storm systems and thunderstorms can tap into and wring out tremendous amounts of moisture.

A recent atmospheric river event brought catastrophic flooding to parts of British Columbia and Washington, the damage from which essentially cut off access to the Vancouver, B.C., metro area by land. The current bout of heavy rain and gusty winds won’t be nearly as prolific as the recent storm, but lots of rain is on the way and the added stress will exacerbate the damage and effects.

The heavy rain will wash over Washington and British Columbia in several waves. The first wave is ongoing tonight through Friday. The next round of heavy precipitation will move ashore late Saturday and stick around through Monday. A third batch of heavy rain will follow soon after and arrive by the middle of the week.

The Weather Prediction Center calls for hefty rainfall totals across the region, especially at higher elevations. 5-10 inches of rain could fall along the Cascades and Coastal Range, which is likely going to compound the damage in hard-hit areas, especially in British Columbia. Lower rainfall totals are expected in the big cities.

The opposite northern corner of the United States is the other area expecting the week’s most active weather. A winter storm moving across Eastern Canada will bring heavy snow to parts of the interior Northeast through this weekend.

Several inches of snow are likely in higher elevations across much of New York, Vermont, New Hampshire, and Maine, with an inch or two likely at lower elevations. The heaviest totals are likely in northern Maine, where some communities could wind up with double-digit snowfall totals by Sunday. Bands of lake-effect snow will also beef up totals along the eastern shores of Lake Erie and Lake Ontario.

[Satellite Image: NOAA]

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