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Sunday, December 31, 2006

New pattern January 10th but with plenty of hurdles

I was hoping that a New Years eve update would be filled with much better news, not so much for the first full week of January but beyond that in particular. I unfortunately do not have very good news but instead filled with more consternation. First we have to contend with another non all-snow event and by the looks of the most recent model updates, we may be hard-pressed to see any snow until January 2nd. I have been watching the period after January 10th very closely since the Arctic Oscillation has shown signs of a shift. What has been confirmed in the last two days is that there will be mechanisms developing in this newly emerging pattern that will bring arctic air back into North America and get several regions of the country very cold. Still we are presented with problems even after our return more seasonable temperatures begins next weekend.

New Years Day Storm
I have looked at all the temperature profiles concerning our upcoming new years storm and am not encouraged. It is unlikely, based on the latest data that we will see any signifcant accumulation of snow Sunday Night before the changover to freezing rain occurs; instead, after perhaps a little snow, there will be a period of freezing rain that may in fact go to plain rain before ending sometime New Years Day. We won't see much of a snow melt with any rain that falls as it is not expected to get much above freezing. We should see some snow as the upper air environment becomes more favorable Tuesday.

Mild weather late next week
It then becomes mild as we head into the end of next week. It would still be a little early to be too definite but record warmth is a big possibility at least on one day late next week. Records (the warm version) in northern and central Vermont in January are defined by 40's across the mountains and 50's in many of the valleys. The unfortunate part of mild weather in the northeast, at least for us skiers, is that a return to colder weather is usually preceded by rain. This too is not a definite for next week but appears very possible either on Friday or sometime during the weekend. The return to more seasonable weather which will follow this onslaught of warmth will mark the beginning of a somewhat new regime, but what excactly will it be and how much will it benefit New England remains to be seen.

The January 10th change
Changes in the Pacific are what look to finally bring arctic air deep into North America. One of the many features that has been a fixture in this most recent pattern is a deep trough situated across western Alaska. This feature will be removed by next weekend and looks to be replaced by a ridge which will extend from the mid-lattitude Pacific up to the poles. This in effect will act as the mechanism for the southward transport of Artic air and if this feature emerges as advertised much of Western Canada and the eastern Rockies stand to get a huge onslought of cold as we head toward the middle of January. Indications are that some of this cold gets transported east but the ridge-trough position is not shown to be favorable for the eastern states to maintain a healthy stream of colder temperatures. Such a pattern would instead favor outbreaks of below normal temperatures interlaced with brief outbreaks of milder temperatures. It is a pattern one would normally see more of in a La Nina as opposed to a El Nino year and I am somewhat skeptical that as we get closer to this January 10th target date, some of the changes and consequences of these changes are handled differently by the models.

Quick Summary
Still signs of a change on January 1oth but many undesirable events await us next week.

1 comment:

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It can be seen globaly, weather is unpredictable these days. Thank you for sharing information with us, keep posting such posts