Sunday, January 26, 2014

Opportunities for big snow increase as we move into February but the core of arctic cold shifts west

The Vermont I know and love seems to be getting back to its normal wintry self. A couple of these little clipper systems have over performed and the mountain is quite literally "inching" closer to a optimal February. That all being said, we have some hurdles to jump over in early February as the core of the arctic cold shifts toward the west. There are some competing forces at play, which can prove to be a very good thing many times, but can be nerve racking as the margin between snow and ice and rain can often be razor thin.

In the shorter term, the mountain will get the benefits of a second clipper system. Some snow Sunday night and an additional period of snow Monday should amount to an additional 2-5 inches. Monday will feature temperatures in the 20's but another arctic onslaught is poised to send temperatures plummeting across the eastern half of the United States. In a relative sense, New England will get spared the worst extremes of this airmass (the Midwest will get that) but readings will fall below zero again on Monday, Tuesday and Wednesday nights and struggle to reach 10 both Tuesday and Wednesday. Temperatures on Thursday and Friday should moderate somewhat. The only snow during the middle part of the week will probably come Tuesday from instability or terrain induced snow showers and flurries.

We just continue to watch and wait for hints of a big storm. As I have pointed out this becomes more likely as we move toward February. The giant upper ridge in western North America responsible for the hugely positive PNA will subside, retrograding both north toward the pole and west into the northern Pacific. There will be energy in the Pacific undercutting this ridge, thus the split flow and thus the opportunity, we hope, for some big things. Because of this pattern evolution, the core of the arctic cold will shift decisively west and this type of long wave pattern puts New England in a battleground as arctic cold will have to fight off milder temperatures for control of the region.

As of Sunday morning, there is some stronger evidence of at least a semi organized weather system around Super Bowl Sunday or shortly thereafter. A storm that will gather strength in the southern plains and head northeast toward New England. In the last 24-48 hours, various models have shown a plethora of results ranging from a big snow event to a snow/ice event. It certainly has the makings of what could be a very good situation for interior New England as a whole but any push of mild air makes us nervous. Beyond the 2nd and 3rd, I expect at least two additional systems to impact the region and with the arctic oscillation settling comfortably into a favorable negative index I think the results should at least be somewhat positive. Still the pattern is not completely aligned with the center of cold favored over the central or western part of North America.


No comments: