2010-11 season to start with a huge bang

Thanks largely to a well established upper-air block in the jet stream across Greenland and the very negative NAO which is a direct result. This is the very same feature which dominated the weather pattern last year, a year where the blocking was so severe and the southern branch so powerful that a succession of storms tracked well to the region's south. A similar pattern this year will yield much more fruitful results as the upcoming week will prove. Our live look at the MRG base might not show much in the way of snow at the moment but the view will be very different in a week's time and discussions of a very grand opening will pick up in earnest !!

Colder weather, which is dominating much of the central part of North America has been a little sluggish in its eastward progression leaving much of interior New England "above normal" though readings have fallen below the critical freezing mark across higher terrain. This will remain the case over the next few days as we witness the Midwest and deep south get a surge of chill by the 5th of the month. As the cold moves south, a storm will take shape across the Gulf of Maine and intensify very quickly. I alluded to this feature in the last post as a possible snow maker and it should prove to be of much greater significance than originally thought. As we progress into early next week, this storm will get caught under the all important Greenland block and retrograde into Quebec. As it does so, a moist conveyor will rotate into the northern Green Mountains and snow will begin to accumulate across much of northern Vermont although the high country will receive the biggest benefits. Between Monday and Wednesday snowfall totals could range in the 1-2 foot category.

The upper trough axis will shift east later in the week and temperatures should fall dramatically by Wednesday. Snowfall late in the week will largely depend on the available low level instability because the Champlain powder machine should be open for business (with the lake being unfrozen). It is tough to tell this early how deep that layer of instability will be but a subsequent post can fine tune that forecast.

Of more significance could be a more potent weather system which should exit the Rockies late next week and have a bit more moisture to work with as it proceeds east toward the region. This storm will be a product of a more consolidated jet stream this year and like many systems this year, the question will be its ultimate track and its ability to gather moisture from the Gulf Mexico since many such weather systems can struggle somewhat in this regard. Even at this early juncture I feel relatively confident for additional snows next weekend and this will make for a fantastic 7-10 days of early season skiing across northern New England. The even better news is the recent indication from the European Ensemble package which suggests a continuation of a blocked up and negative NAO dominated pattern through the 15th to 17th of the month. This will really limit the chances for any significant thaw or rain through the middle of December.

Lastly, I wanted to expand on this whole "favorability index" theme which will be a more objective measure of the three teleconnection indices that the SCWB keeps an eye on. The index is a cumulative measure of the NAO, PNA and AO over the next two weeks with the signs of the NAO and AO flipped. More importantly, a favorability rating of over "2" is excellent while anything under -2 is rather unfavorable. Hopefully this will keep me honest and perhaps keep me out of trouble !! Enjoy the early season turns.