I am not the weather guru but I saw a post from skiing weather man that might give us some hope to return to the cold pattern 2-3 weeks from now.
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Monday, January 26 2009 @ 03:33 PM
Inserted by: Herb Stevens
As January starts to wind down, it is becoming clear that 2009 will not bring about a January thaw. Cold, arctic air has dominated the eastern half of the country for almost the entire month, and it will hang on until we turn the page on the calendar. Changes to the jet stream over the Pacific Ocean have brought about the beginnings of a pattern change that will begin with a messy storm from the southern Plains to the Northeast this week. The storm will bring some significant snow to some resorts, with an icy combo in many of the lower elevations east of the Appalachians.
Now, while one arctic air mass after another has been dumping into the eastern half of the U.S., a strong ridge at the surface and aloft has dominated much of the month in the West, leading to bluebird skies, but also strong inversions and valley fog. As the pattern has changed over the past several days, a couple of moist Pacific fronts have moved ashore and all of the ranges from the Cascades and Sierra to the Wasatch and the Rockies have picked up some new snow and softer surfaces have been restored.
The Upper Midwest continues to benefit from lake effect and the passage of the occasional Alberta Clipper, and their fine season continues. The central and southern Appalachians got off to a bit of a slow start this season, but the cold of the past couple of weeks has those regions looking good as we pass the halfway mark of the season.
As I mentioned, this week will bring a very complicated storm northward from the southern Plains. The energy for the storm has come from the southern branch of the jet stream, which got fired up as the result of some changes over the central and western Pacific. That southern branch will continue to be a player in the near future, and that means that the dry snowfall of the past several weeks will not be as common. High pressure is stretched out from the Great Lakes into the Northeast, and as the southern jet lifts northward, it will attack the cold dome of air to the north.
The first impulse will bring some light snow to central Appalachians northward to about Interstate 70 Monday night and early Tuesday. The second part of the storm will be stronger and juicier, and it will produce more in the way of precipitation. A primary low will push into the Ohio Valley before a secondary low takes over close to the Delmarva Peninsula.
The effect of having two systems involved is that some of the cold air will be used up with the initial shot of moisture. That, plus the fact the primary low will help propel some mild air in the mid levels from the south to the north, means that Tuesday night and Wednesday's precip will be a mixed mess about as far north as Interstate 80, as well as along the coast from Philly to Boston.
The snow will reach most of New York and New England, with 6 to 8 inch amounts common, along with a few that top out at 10 or a little more. In the wake of the midweek storm, colder air will return, but right now, it doesn't look as though it will be a repeat of the past two weekends, when temperatures were cold enough to have a negative impact on business at many resorts.
The snow in the West will wind down by midweek, with lighter snows later this week, due to the passage of an additional Pacific front. The weekend in the West will be a very pleasant one to enjoy the snows of this week. Now, next week will start out cold in the East, and seasonable in the West, but by the 5th or so, the pattern will become more zonal across the country. That means that the jet stream will be moving in a basic west to east fashion, which will reduce the input of cold air from Canada.
A period of a week or so of above normal temperatures can be expected in the East from roughly the 5th to the 12th, although it will not be a major meltdown, as the core of the relative warmth will be found over the Plains. Any warm air that tries to move eastward will be modified by the extensive snow cover that will only be beefed up by this week's storminess. It will be warmer than normal during that stretch, but only by 2 to 4 degrees or so. It will still be cold enough for snow to fall north of I-80, but south of there I think we will see a break in the recent weather that has been so helpful to the industry in the mid Atlantic and Southeast.
There are two indices that suggest to me that we will see a return to colder, snowier weather in the East from the middle of February into early March. First of all, the Arctic Oscillation looks as though it is going to turn strongly negative, which suggests that much of the cold air stored up close to the pole will spread out to the lower latitudes. Also, the stratosphere over the higher latitudes is undergoing a dramatic warming trend, which is another precursor to a cold spell in the lower 48.
With a blocking high expected to remain over the North Atlantic for the foreseeable future, the path will be paved for the delivery of a renewed cold shot 2 to 3 weeks from now. And if the southern branch happens to send along a major short wave that can interact with the advance of the new arctic air, the block will help to spin up a major east coast snowstorm, which I believe will be part of the landscape later in February.
Until then, we will see a continuation of packed powder in most spots for the next week, with some transformation of the surfaces when it runs milder than normal a few days after Ground Hogs Day. Punxsutawney Phil will likely see his shadow, as a brief dry warm-up will occur in the East next Monday before another cold front sweeps through the East. In the West, this is a going to be a snowy week, with a bluebird weekend on the way as a ridge forms over the Rockies once again. That ridge will hang around until later next week, when the snows will return again.
The first half of February will be milder than normal over much of the country, but because the southern branch will remain active and a blocking high is waiting over the Northwest Atlantic, storms with snow are not off the table...it just might work out that the only below normal days in the first half of the month will occur when a storm moves through. By the time the middle of the month rolls around, arctic air will be poised for another assault on the lower 48. Overall, the news is good, so get out and do some sliding!
