Sunday, February 15, 2009

Track of late week storm continues to trend north

This trend has been a consistent one for a few days now and a storm that looked at one point to be taking aim at the Virginia Tidewater is now taking aim at MRG. The ideal winter storms do not track right at MRG as some of you know and we would prefer they track toward Boston leaving the spine of Green Mountains safely on the snowy flank. This storm still has a few days to make up its mind but a track toward MRG would limit the upside potential for powder and would mean a snowfall range of 12-18 as opposed to 18-36. If the storm tracks further south then our snowfall potential would again rise. Such a result may seem unlikely considering the trend but with a high latitude block fighting on our behalf we could certainly see expectations change in our favor at the last second.

Storm and all its details
In the meantime all will stay quiet. Flurries Monday will not amount to much and Tuesday should feature plenty of sunshine which will accompany this latest round of chilly temperatures. It will not be until Wednesday when clouds and eventually snowfall arrives from an already intense approaching storm system. If the storm tracks according to current expectations, it will deepen to 990 mb by the time it cruises through southern Michigan late Wednesday. It will continue to strengthen as it tracks toward Vermont and snow will overspread MRG late Wednesday. Snow will become very intense Wednesday night as the storm efficiently makes use of the available moisture from the warmer Atlantic Ocean waters. Because the low pressure center is tracking so close to the mountain, there are some inherent concerns. 1) Any storm passing this close is likely to bring a dry slot which will mean a period Thursday when no precipitation is falling or falling very lightly. 2) A storm passing this close can bring mid level warmth, that if strong enough, can cause a change to sleet or freezing rain. I am not overly concerned about the latter and the former isn't really that big of a deal. Snow will be heavy enough Wednesday night to accumulate 8-12 inches by first tracks time Thursday and a dry slot might at least make travel a bit safer and easier even if it does mean less powder. The pool of instability which will move over the mountain in the wake of the passage of this powerful system looks impressive. It will be enough, I think, to cause significant terrain induced snow beginning later Thursday and persisting into Friday. The three day snow total ending Friday may surpass 20 as a result but that should be a best case scenario only at this point.

Yes there is still another system to watch
There is then the question of the next system which will impact portions of the east coast between Sunday the 22nd and Tuesday the 24th. This is a system that will be spawned by a vigorous piece of jet energy diving southeast out of Canada. This is the "Manitoba Mauler" and may prove to be a memorable one for some location along the east coast but the question is where. The storm will ensure that the upper trough along the east coast is reinforced and it is possible that the system and its energy will be too far south to mean additional snows at MRG or we could again see a northward trend, another sequel to a movie that has repeated itself more than a few times this winter.

Milder weather very late in the month
The last item of note relates to the long range. After the round of chilly weather beginning on the 21st and ending around the 25th there are new signs of a stretch of milder temperatures. A few days ago it looked as though the negative NAO would hold through the balance of the month and would ultimately cause a big stretch of cold and sometimes powdery weather for us on the mountain. It now looks like the blocking negative NAO will break down somewhat and be replaced by a trough west/ridge east scenario that could then lead to an late February thaw. It would be very late in February though with no threat of extreme warmth or any rain until the 25th of the month at least.