Think Snow, Tweet Snow !!!

Monday, February 22, 2010

Mammoth storm to bomb and stall across New England

and with it will be a wild few days of weather across not only the Green and White Mountains but all of New England, New York State and southward to New Jersey and eastern Pennsylvania. It is a complicated weather map to say the least but will largely be dictated by an amplifying upper trough which will evolve into a "closed low" which will position itself near Martha's Vineyard by Friday.

As of early Tuesday, snow has already made it to much of New York state but this moisture is associated with a decaying low pressure area in the eastern Great Lakes and much of it will likely fail in its attempt to reach the Vermont high country. Meanwhile a new area of low pressure will gather strength over the open waters of the Atlantic Ocean and move north over eastern New England. This surface feature will swallow much of the energy from the eastern Great Lakes low and push moderate to heavy snow to MRG Tuesday evening. The snow will accumulate significantly and should provide the mountain with its best powder day in weeks with somewhere in the vicinity of a foot by first tracks time Wednesday.

This initial burst of snow however results from a storm which is not even likely to deepen beyond 1000 mb as it tracks through eastern New England; in fact the storm will begin to lose its potency as another far more dynamic system begins to take shape just behind it over the Atlantic. This new storm will deepen very rapidly thanks largely to the full backing of upper level support approaching from the west. It will also have the necessary baraclinic ingredients of much colder weather approaching from the west mixing with the relative moist warmth of the Atlantic. The result will be an all out explosion near the New England coast and a low pressure area which may eventually deepen to near 980 mb (Valentines Day '07 levels). This second and more dynamic system will give us a little head fake in its initial north-northeast movement but will ultimately turn north and then retrograde west as it gets sucked into the closed upper low mentioned in the opening paragraph.

We should see the snow Wednesday lessen its intensity for a time as this new storm consolidates its power and then the high drama begins. Models have given us some conclusive evidence regarding the snow through Wednesday but what happens after that remains somewhat uncertain. The newly released high resolution NAM and the two most recently released GFS runs allow this storm to deepen and move west with such ferocity, that a "warm tongue" from the Atlantic Ocean literally slices through interior New England allowing a second round of snow to become rain across valley locations and perhaps parts of the high country as well. It is very hard to fathom but it would not be a meteorological impossibility given such a storm. It would be very similar in fact to the February 10th set up as rain prevailed across the Boston area while snow was falling in locations much farther south like the nations capital. In this instance, rain could be falling in some of the valley areas of Vermont Thursday while snow is falling in New York city. This however is just hypothetical and since this is an occluding storm the effect of elevation will work in MRG's favor. The European model is also suggesting a more favorable outcome with the storm and its "warm tongue" much farther north and much of the state remaining safely in the snow zone.

So with a bit of information overload in the above paragraph the boiled down details would appear as follows. The lighter snow late on Wednesday would become much heavier snow Wednesday night and early Thursday. This should allow for another round of epic turns Thursday morning at the very least. During the day however temperatures could climb and snow could turn either very wet at the base or turn to rain. If the European model wins the argument, snow would simply continue at varying intensities. Once the storm undergoes this occlusion, we will see sporadic lulls but much of the energy from this very impressive weather system will remain across New England through Friday, Saturday and Sunday. In addition the "warm tongue" if any does evolve will simply dissipate by Friday and we should be looking at a steady light to moderate snow through at least Friday and Saturday. The snow totals will thus be immense and the big challenge will be whether or not we can avoid the rain on Thursday.

Here is a summarized break down using first tracks time as a frame of referenced

First tracks Wednesday: Around a foot with 2-4 additional inches during the ski day

First tracks Thursday: 6-12 new inches with snow or mixed precipitation during the day

First tracks Friday: At least a few new inches, but light to moderate snow throughout the day providing additional powder

First tracks Saturday: Additional powder consisting of several inches.

Do the math here and you get some impressive totals.

Thursday will feature a lot of wind as the storm reaches its peak intensity. Winds will slacken gradually on Friday and into the weekend. Temperatures will generally be in the 20's Wednesday, near freezing Thursday and back in the 20's in the Friday-Sunday time frame.

And as if to prove how streaky mother nature can be, another huge amplification in the jet stream is likely during the middle of next week leading perhaps to talk of another big storm or at least some additional powder. This would be in the early days of March.

Updates will be required and changes in the forecast, particularly the timing should be expected so please operate under that assumption. Other than that, I appreciate all the interest and all the emails. I apologize for not responding to some but appreciate the comments nonetheless.

8 comments:

Harvey44 said...

Good things come to us who wait. (!)

Shelby said...

The powder gods be praised

Brian said...

BRING IT ON ALREADY!! This has been a meteorologically bizarre winter to say the list. The Winter Of Wind hopefully will deliver a Spring Of Snow.

Some people got a bit feisty during the last couple of weeks when snow forecasts turned out to be incorrect. Gotta love/hate Chaos Theory!!

Thanks Josh for all that you do here

-Brian at MidStation

Brian said...
This comment has been removed by the author.
Jonathan said...

Reading this report is almost as much fun as skiing.

Kristen S. said...

I'm happy for y'all!! (oops, sorry - I keep forgetting that "y'all" ain't allowed up there - I'm in soooo much trouble when I move back!)

Nancy said...

I really appreciate your forecasts...and thanks for the day-by-day (forecast) breakdown of snow.

Jer said...

much thanks for the tireless forecasting