Busy Storms. Slopes in Good Shape.

As I write this piece at the start of President’s Day weekend, the slopes from coast to coast are in fine to extraordinarily good shape, thanks to a very busy coast to coast pattern of storms that has played out in recent weeks.  A push of arctic air delivered by the stratwarm episode that was discussed in last week’s column is providing cold air over the eastern two-thirds of the country.  At the same time, upper level energy that supports the stormy pattern continues to be ejected from an upper level trough over the Aleutians.  After the holiday weekend those disturbances will continue to favor resorts north of I-70 and I-80 in the West, but as the energy tracks eastward and interacts with the cold air flowing into the center of the country from Canada, storms will bring fresh snow to the Midwest and the East.  Here is a jet stream for Friday the 19th that illustrates the snowy “handoff” pattern that is in place now and should stay in place for the next couple of weeks.

With one trough over the Gulf of Alaska and another over the eastern half of the country, combined with a blocking ridge still hanging around Greenland, storm after storm will cross the country, some small, some more significant.  Initially, the snow will fall in British Columbia and the resorts of the Pac NW and northern Rockies.  The northern Great Lakes will pick up a round of powder as the disturbance heads toward the high amplitude trough that stretches from the Great Lakes to the Gulf of Mexico.  As the disturbance in the northern branch of the jet stream interacts with the larger system, the result could be a storm that could run up the length of the Appalachians late in the week and into next weekend.  As I suggested earlier, there will be ample cold air around, as shown by this map of 5,000 foot temperatures for next Friday.

The green and gray colors show where temps will be below 32 degrees aloft, a proxy for snow vs. rain at the surface.  You can see that a long-track snow event up the eastern seaboard could indeed be in the cards.  Now if you look at the jet stream map above, you will see an extended trough reaching from the waters west of Washington northward to the Arctic region.  The counter clockwise flow around that feature suggests that after 10-12 days of domination by arctic air, Pacific air masses will get involved, leading to somewhat milder weather (less cold) by the end of the month or so.  In the meantime, enjoy the frequency of flakes and preponderance of powder!

REGIONAL HIGHLIGHTS:

Pac NW/B.C.:

Big storm late this week followed by more storms from the Gulf of Alaska rolling into the mountains of B.C., Washington, and Oregon.

Central and southern Sierra:

One storm this weekend and another early next week.  Glancing blows from storms to the north bring light snow later next week.  Heavy snow next weekend.

Rockies:

Weekend snow followed by a moderate to heavy accumulation a couple of days later central and south.  Potential for another round next weekend.  Moderate amounts of snow next week in northern resorts

Midwest:

Arctic air dominates.  Light snow from Clipper systems and some lake effect snow in northern Lakes.

Northeast:

Parade of storms continues to add snow every couple of days.  Shot at significant snow middle of next week and again late in the week.

Mid-Atlantic/Southeast:

Two shots at moderate to heavy snow in next week…first one around Tuesday and again a couple of days later.

 

 

One Comment

  1. Herb: you reminded us in Map #2 what the colors represent would be helpful to remind us what the colors represent in #1.

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