Sunday, January 6, 2013

Thaw for the upcoming weekend, but lots of promise for the end of January

The Sunday snow concludes one of the better stretches of early season skiing the mountain has seen in the last decade or so. Even in some of the big winters like 07-08, and 2010-11, big warm ups during the Christmas and New Years holiday vexed us a bit. This year, it will be a mid-January thaw that crimps our snowpack. We may however, have reached a bit of a turning point. This point being defined by the time at which I have become convinced that the building snow pack will not be completely blow-torched away by a thaw. This point being the time when we see the light at the end of the tunnel before even entering the proverbial tunnel.

Arctic chill will continue to grip the region through Monday night meaning seasonable January temperatures. The evil empire then brings its dreaded Pacific air to the region Tuesday. The deep snow cover across interior New England, low January sun angle and lighter winds Tuesday and Wednesday will keep the effects of the pattern change more on the minimal side. Temperatures will challenge the freezing mark both Tuesday and Wednesday but will not get past the mid-thirties except perhaps in the Champlain or Connecticut river valleys. The sun angle plays an especially large role here since the same set of weather parameters might yield temperatures in the 50's were this mid-March. Models have also redefined our late week weather a bit and not in a bad way at all. Instead of commencing an onslaught of mild southerly breezes and excessively above freezing temperatures, a vigorous upper air Pacific Ocean disturbance will be allowed to track across the Great Lakes and drag a limited amount of both instability and colder air to the region. Temperatures will remain on the milder side of average but snow showers Wednesday night and Thursday along with sub-freezing temperatures is much better than what the forecast looked just 2-3 days ago. Such weather does not melt snow.

The big trouble period begins late Friday and persists through the weekend. It is at this point when we get flooded with mild air and ultimately get a period of rain. This happens as the pattern becomes more amplified with a deepening trough in the west and an even more well-defined upper ridge in the east. It will unfortunately be a bit ugly as a storm system gathers steam in the middle Mississippi Valley and heads well into Quebec. The period of rain is likely Sunday, although some of this also timing could again be re-adjusted. Temperatures could get into the 50's as well, a full 30 degrees above average and enough to challenge a few records but thankfully this should not persist too long.

When trying to assess the evolution of the long range weather pattern, I have always tried to look at the picture on a grand scale and tried to pick out big features on this scale that might win the day. It is a very inexact science since not only can your own assessments be wrong but the assessments of the model guidance can also be wrong. Although the evil empire is clearly the big feature during the next week or so, the negative North Atlantic Oscillation (NAO) will challenge its dominance and eventually, in my opinion, become the alpha as we head toward the last third of January. The battle between the evil empire and the NAO could be an epic fight, especially between the 14th and 20th of the month and the fight will be manifested in the form of a few storm systems during this period. The pattern will support the return of some very cold air across the plains and eastern Rockies and will ensure that this month will be one of the eastern Rockies coldest January's in a while. The pattern however will also support the continuation of mild air across the southeast and Mid-Atlantic states.  Storm systems will form in the southern plains at the junction point of the very cold arctic air and warm moist air from the Gulf. The storms, perhaps one of them turning very potent will move toward the eastern Great Lakes and threaten to bring warmer temperatures into New England. There should be a decent overrunning surface to support some snow but too much warm air means sleet and freezing rain and perhaps even worse if a strong storm were to move well into Quebec again.

The farther we move into late January, the more favorable the prevailing forces become so although the next weekend looks a bit slushy, futures weekends appear much better.

And I almost forgot. Hockey is back

2 comments:

Paul said...

GO LEAFS GO!

Paul said...
This comment has been removed by the author.