Saturday, March 8, 2014
As we move into the final few days of the month of January, the coldest week of the year, yet another shot of arctic air is sweeping into the Northeast.
This will be the fourth time this year that a significant piece of cold has been delivered into the region without much in the way of moderation, thanks to the extensive snow cover over which it travelled from the high latitudes, as well as because of the speed with which it arrived. The jet stream configuration has had everything to do with the trajectory and the speed of the cold shots. Thus far this season, the dominant set up has been one with a western upper level ridge and an eastern North American trough - something like this:
Courtesy of NOAA
The ridge has been supported by a very and extensive pool of warm water in the northeastern Pacific Ocean. The Pacific warm pool is going to be a major player in the weather pattern for the remainder of this winter, and in general terms, we should consider it an ally for our skiing and riding interests here in the Northeast.
The strength of the ridge has combined with the strength of the low you can see over Hudson’s Bay to produce a fast and consistent delivery mechanism for cold air with its origins in the polar regions, and at times, it has tapped into air that was chilled in Siberia before being lifted up and over the pole. The tight packing of the lines that you see between the two features is consistent with a fast flow, and even though we have fought our way through a number of storms that produced a mixed mess of precipitation types, it never took very long after any warm-up before cold rushed in and got the snowmakers back on the job.
While the cold has certainly been welcomed, in the past 10 days or so, we have had too much of a good thing. The northwesterly flow of arctic air has been so strong, it has suppressed the storm track well to the south, and the only snowfall most of the Northeast has received has come from moisture-starved Alberta Clipper lows. A great example of the suppressed storm track will unfold this week, when low pressure brings appreciable snow to portions of Georgia, South Carolina, and North Carolina. The storm will track out to sea before it gets anywhere near the Northeast.
Now, when we get to February, most resorts would like to be able to roll up the hoses, blowout the pipes, and shut down the snowmaking systems, because those machine-made crystals aren’t cheap. Base depths are not as deep as most operators would like to see them heading into the second half of the season, so most will continue to make snow whenever possible.
The good news from a weather standpoint is that the pattern is about to undergo a change that will lead to a very stormy February, one that I believe will bring above normal snowfall amounts to much of the eastern United States. The main reason for the change will be a shift in the jet stream setup, and to illustrate what that shift will look like, here is a forecast for 10 days from now.
Courtesy of the Canadian weather service
As long as the warm pool in the Pacific remains in place, and it will, there will be ample cold air fed into any storms that move into the region to produce snow most of the time in the mountains. It shapes up as a classic battle between air masses, and promises to keep forecasters on their toes. More importantly, it bodes well for powder lovers, and for anyone booked into a resort for the upcoming President’s Day vacation week.
In the shorter term, the first half of this week will be very cold, but with an extra layer of clothing, you’ll be able to take advantage of smaller midweek crowds and some very nice snow. Temperatures will start to modify later in the week, and as the jet stream relaxes and turns more westerly, the parade of low pressure systems should get underway, with some light snow across the mountains that should just be the start of a very snowy February.Tweet
As The Skiing Weatherman, Herb Stevens has been the go-to guy for snow conditions for skiers and riders for more than 25 years, first on televisions stations up and down the East Coast, and now on newspaper-related web sites. A lifetime New England skier, Herb travelled the world as a caddy on the PGA Tour for five years before launching his career as a meteorologist. After one year at WJAR-TV in Providence, R.I., he became one of the original on-camera meteorologists at The Weather Channel, and later was chief meteorologist at WNYT-TV in Albany, N.Y. While at WNYT, Herb pioneered a weekly on-snow ski report, which later became his full-time job as The Skiing Weatherman.