Monday, January 19, 2009

Cold retreats for a short time then returns; More active weather starts the last week in January

The cold not only shattered records all across the state of Vermont on Friday but for most locations it was the coldest morning of the decade. It was a very warm decade statistically but an impressive feat nonetheless and for those brave enough to face the elements a few days ago, you have earned your bragging rights. The extreme cold has made a temporary retreat although we do expect a return later in the week.

As of Sunday, Mad River Glen was on the fringe of a developing coastal system impacting much of New England. As it turns out, coastal sections will get most of the snowfall but the lower atmosphere is moist and unstable enough for continuous snow showers and flurries throughout MLK Monday. It may only amount to a light additional accumulation but it should freshen the trails up somewhat and with the relatively moderate temperatures and light winds it should be a solid ski day. The intensity of the east coast trough is such that the Atlantic Coast is a stick of dynamite just ready to ignite and blow and I know we talked about a possible coastal storm on Tuesday. This storm, appears as if it will come into being but will likely be too far off shore for a New England impact of any kind; instead, areas of the eastern Carolinas that rarely receive snow will get a few inches. Mad River will see more in the way of snow flurries Tuesday and into Wednesday but with minimal accumulations. We have a better chance of getting a few inches Thursday when the mountains get into an area of overrunning thanks to the push of milder weather.

We will see the moderating temps this week as promised but this is a very short-lived trend. Lake Erie is now almost completely frozen, there is an unusual amount of ice on Lake Ontario and almost half of Lake Huron is frozen. This makes it all easier for unmodified arctic chill to advance quickly into New England and it will do just that this weekend. The frozen Great Lakes can assist us however since they no longer have the same magnetic pull on developing low pressure systems. Friday will be the day when the first such weather system will test the partially frozen Great Lakes. This system is working with little energy and flying eastward on the wings of the advancing push of arctic cold. I would expect some snow with this on Friday into early Saturday but accumulations will held down by the storms quick eastward progress. The cold weather will hit late in the day Saturday and Sunday could be another where temperatures are in the -20 vicinity in the morning and struggle to zero during the afternoon.

We are in the process of losing the strong western North America Ridge and with it the positive PNA index. The other two teleconnections (AO and NAO) are expected to gradually become slightly favorable even as the PNA turns negative. The result will be a much more active pattern across the U.S. and eventually interior New England and Mad River Glen. We will see a consolidated flow of pacific energy and numerous weather systems crossing the country from west to east. The more active jet will undoubtedly deflect arctic air away from parts of the nation but northern locations such as Vermont have the capability of staying on the chilly side of these systems and the results can often be very fruitful. I am in fact looking for some big things out of the weather between Jan 25 and the first week in February. There is a risk for the rogue storm taking the St Lawrence Valley highway and producing the icy mixture we would like to avoid but I am optimistic and will stay so until i see evidence to the contrary.

And I finally joined the Mad River Glen facebook group as the 557th member. Considering i run a weather blog in honor of the mountain that is somewhat embarrassing but for those who haven't joined go ahead and do so.

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