Sunday, November 29, 2009

Cold air ready to make a southward push but we need to be patient with the snow

The most effective way to get cold air in high quantities down into the United States and more importantly into New England is to have a high latitude "Omega Block" in the jet stream. One is expected to develop over the course of the next week. It will be closer to 145 degrees west, or over Alaska and one would prefer it to be situated closer to 120 west. It will thus take some time I think to enjoy the fruits of such labor if you can call it that. We will need to be patient and remember that December can be very discrepant about delivering the goods even when cold air seems to be prevailing. Such will be the case perhaps over the next two weeks but by mid-December, I think much progress will be made as far as getting the season off to a positive start.

It has been awhile since we have had any intrusion of widespread cold in the United States. This will change later this week and as it does so, the southern branch will produce its first in what should be many major weather systems. Model guidance from both the American (GFS) and the European (ECMWF) suggest that the storm will track too far inland and that the supply of cold air in front of the system will be limited at best. It is thus appearing very likely that we will see mostly rain from precipitation that should fall through much of the day this Thursday. Both cold air and some instability will arrive in the wake of this rain for the weekend and this should some light accumulations of snow to the Vermont high country but it will not be enough to open MRG.

The "probable" rain on Thursday is one of the consequences of the "Omega Block" in the jet stream located at 145 instead of 120 west. There is a chance that the positioning of critical features such as this "Omega Block" will improve and ensembles indicate that teleconnections will become more favorable as time progresses. I am not entirely sure of this however and would offer the possibility that another system similar to Thursday's could bring mixed precipitation as opposed to all snow to the region sometime around December 7th-8th. Thereafter, however, I think much colder air will maintain control of New England for at least a week through mid December. With this will also mean a chance for meaningful snow between December 8th through the 15th.

Thats all I have for now, we can dive into details as they come more relavant to skiing.

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