Ski Weather - March 20, 2010

In last week's report, I pointed out that the pattern had one more shot of arctic air in it before it morphed into a decidedly springtime configuration, and that still looks to be the case. It will come in two shots...the first is underway as I write this summary, with snow falling as today (Saturday) as far south as the Red River Valley between Texas and Oklahoma. Some snow is falling on the resorts of Wisconsin and Michigan, which may temp management to squeeze out one more week of skiing and riding, as the cold (at least at night) will help sustain base depths in the Midwest this week.

The Rockies have enjoyed a couple of significant snowfalls in the past ten days or so, and aside from some soft conditions in the lower elevation, conditions are nice...there are some "grunkel" spots showing up in the northern Rockies due to below normal snowfall in the past month. The East is basking in a spring preview this weekend...it is currently 72 degrees here at my home office in Rhode Island, and the warmth of the past 4 or 5 days will claim a good number of lower elevation resorts by the end of this weekend.

Now I know it seems like the news is not good all over...very warm in the East, with the most significant snow falling in the middle of the country where there are no hills! Alas, there is some good news...a second shot of cold air will press into the Lakes and Northeast later in the week of the 22nd, and then a low pressure center will take shape in the southern Plains, move northeastward, and potentially bring one more meaningful snowfall to the Northeast next weekend.

Here's a look at the expected standard deviations of temperatures over Canada for the next 10 days...

Less than two weeks ago, almost all of Canada was covered by positive anomalies, but the shifting of an upper trough over Alaska to a position south of Alaska has allowed an upper ridge to build in northwestern Canada. That feature tapped into some very high latitude arctic air, which has flowed into central Canada and turned things colder. That cold pool will act as a source region for the eastern half of the country for the rest of the month. By the looks, that will do it, though, as I expect the jet stream pattern will re-shape itself during the week of the 29th and flood the U. S. with Pacific air as we head into April. That west to east zonal flow will dominate much of the time in April, which will effectively shut off access to any cold air from Canada. Heck, after turning colder the past couple of weeks, Canada is also going to experience a zonal flow early in April, and much of the country will turn milder than normal, as well.

Once we get into April, in spite of a lack of cold air, we will see some snow in the West, because it will be easier than it has been much of this winter for Pacific storms to penetrate inland. Now, a zonal flow will mean higher snow levels, but the upper reaches of the resorts that stay open in April in the West do have a shot at some powder days next month. In the Midwest, once this double shot of colder air runs its course, the end will come rather swiftly, I believe, and the same can be said of the central and southern Appalachians, where the higher sun angles tend to "vaporize" snow pretty quickly by the end of March. The Northeast resorts that have designs on staying open well into April could really use an "insurance storm" next weekend, to help boost the base depths for the final few weeks of the season. Right now, it does look as though snow will fall in the mountains of New York and New England over the weekend of the 27th and 28th, but as I mentioned before, that could do it for this season in terms of natural snowfall that adds up to anything. By and large, it has been an outstanding season in much of the country, and there still are some fine days to be enjoyed on the slopes...as a friend said to me the other day...you make the most of the last 2 to 3 weeks of summer, so why not make the most of the final few weeks of the skiing and riding season!?!?!?!

REGIONAL SUMMARIES:
NORTHERN ROCKIES/NORTHERN COASTAL RANGES/WESTERN CANADA
The pattern will be rather benign for the foreseeable future...much as it has been for the bulk of this season. There will be an occasional light snowfall from a weakening Pacific system, but not major snowfalls are in the cards through the end of this month. North facing runs are still dry in the higher elevations, but lower elevation runs are starting to soften up quite a bit, and slopes that have any sort of a southerly exposure will start to show thin spots from this point forward.

SOUTHERN COASTAL RANGES/SOUTHWEST
After a productive February and first half of March, the slopes are very well stocked with snow for the stretch run of the season. The higher sun angles as turning lower elevation runs rather sloppy during the afternoon hours, but there is still some fine packed powder skiing and riding to be found higher up. As we move into April, a weak trough in the mean flow will set up over the Southwest, which will help to generate some snowfall, but with a weakening El Nino, it looks as though the prospects for major dumps are waning. Nevertheless, a bountiful snow year has this region in good shape for the final few weeks.

CENTRAL ROCKIES
Some good snowfalls over the past 2-3 weeks have spruced things up in the central Rockies, but base depths are a little thin for late March at many resorts. With the threat of significant snow dwindling in the next few weeks, some resorts might have to close down some terrain earlier than usual. New snow is not completely out of the question, though because a weak upper trough will be present in early April.

UPPER MIDWEST
The resorts of Wisconsin and Michigan will pick up some fresh snow during the weekend of the 20th/21st, but a rather lackluster snowfall year will likely spell the end of the season at most resorts by the end of the month...base depths just don't look deep enough to sustain skiing and riding much longer than that. Cold nighttime temps during the week of the 22nd will help to preserve the snow on the hill, though.

MID ATLANTIC/SOUTHERN APPALACHIANS
The resorts from Pennsylvania southward to the Smokies of North Carolina have had an amazing year in terms of snow, and they have plenty to make it to their closing dates later this month, and in some cases early in April. Some resorts took too big a hit from the rain of the weekend of the 13th/14th, and have closed., Mountain snows are a possibility during the weekend of the 27th/28th.

NORTHEAST/EASTERN CANADA
Mixed precip will fall in the mountains of New York and New England early in the week of the 22nd, followed by several days of colder temps...cold enough at night to preserve the snow on the trails. Trail counts are shrinking at many resorts, due to the warmth of the past several days. Later in the week of the 22nd, low level cold air will bleed into the mountains of the Northeast, and when a surface storm moves up the coast early in the weekend of the 27th/28th, there is the potential for a significant snowfall in the mountains. That should just about do it in terms of big snows for this season, due to the expected pattern change to a milder zonal flow by early April.