The Skiing Weatherman: Changeable East, Snowy West and Mid-West

The West Continues To Luck Out, Cold Coming East By Month End.

Despite a wildly changeable run of weather in the East recently, I managed to get two days of wonderful winter turns in early this week. It snowed on Monday at Sugarbush as I skied packed powder with my son. Wednesday at Killington surfaces were just about perfect packed powder early on and then an arctic cold front arrived. It brought fresh snow: three inches in 30 minutes! An absolute whiteout that gave me a chance to focus on my toes with each turn, a method I was taught decades ago to deal with low visibility. It still works!

Changeable weather will continue to rule short term in the East while much of the West continues snowy, but that imbalance will be changing in the near future. The past couple of weeks, the jet stream maps across the continent have featured a trough centered over the West and a ridge over the East. The trough has produced tons of snow, particularly in the Northwest and coastal ranges of British Columbia.

As this week comes to a close, another storm will cut southeast from the Gulf of Alaska and dump on B.C. as well as the WA and OR Cascades. Lighter snows will reach down to Tahoe as well as the northern and central Rockies. Over the eastern half of the country, a low will cut northeastward through the Great Lakes and into Ontario and Quebec.  That’s great news for the resorts of Michigan, where significant snow will result. Further east, the northern track forced by the strength of the southeast ridge means another mild, wet event this weekend before colder air returns Monday. The “cutter” track is consistent with the current warm state of the MJO, as discussed last week.

Changes are coming, though, and by the final week of the month, the changes will be dramatic across the country. A pool of very cold air has been building in central and western Canada and due to the density of that air mass, it will start to spread southward and eastward. Here is a look at a forecast for the 5,000 foot temperature anomalies for ten days from now that I agree with.

The 5,000 foot level is a forecasting proxy for surface temps, and you can see that a large mass of colder than normal air will cover much of the eastern half of the country by 19^th or so. Meanwhile, the West will turn a little warmer than normal, but not until after some of the arctic air descends through the Rockies later next week. At the jet stream level, the setup will flip, and we will find a trough in the East and a flat ridge out west.  Here is a reasonable jet stream forecast for the same time.

Now, any change in air masses and jet stream features of this magnitude will come with a stormy transition, so there is reason for optimism for eastern snow, at least north of the Mason Dixon line, from late next week onward. Once the new pattern settles in, I expect it to dominate through the bulk of rest of the winter, due to the anticipated influence of the warm water pool in the northeast Pacific Ocean.

Here are the regional details.

Northwest U.S./Western Canada: Another heavy snowfall is coming this weekend, light snow in AB.

Periodic lighter snows will continue next week as arctic air presses southward.

Cascades and Sierra: Snowy weekend with heavy amounts in OR, tapering down further south in CA.

Lighter snow continues next week as it turns windy and colder.

Rockies: Northern Rockies catch light snow this weekend but as several upper level short wavelength disturbances move through the first half of next week, persistent light to moderate snow will provide daily “refills”. Each successive trough will draw arctic air further south, reaching the Tetons by mid-week. Light snow in central Rockies first half of next week.

Midwest: Messy weekend storm lower Lakes, snowy in northern Lakes, narrow ice storm in the middle.

Some light snow northern Lakes from a Clipper or two next week.

Northeast/QB: Another cutter brings wet and icy weather to the northern mountains of NY/New England this weekend, snow up in Quebec. Renewed snowmaking and light Clipper snow next week, with bigger storm threat late. Pattern will look much better a week from now.