Friday, December 4, 2015

Mild, mild and more mild but storminess should start to increse late next week

A couple of days into December and I am still wishing I had some better news to deliver. For the upcoming few weeks there are two big fundamental variables which are destroying the first full month of skiing for us. 1) Tightened jet across the Pacific which can be measured somewhat by the positive EPO index 2) Positive AO (Arctic Oscillation) indicating, especially in this case, the complete lack of high latitude blocking in the jet stream. The best we can hope for through about the time of the winter solstice is for a real juicy weather system to deliver some big snow without much help from significant cold, since we are not expecting much for a time.

We have entered into that dry period I was talking about a few days ago. The weekend will be dry and mild including temperatures around 50 Sunday. More clouds on Monday should keep temperatures in the 40's but even that is at least 10 degrees above normal for the high country of Vermont. There is an upper level system early next week worthy of mention. This feature is an offspring of the energy in the Pacific. The feature will pass unnoticed across the Midwest but will help energize a coastal low near the Virginia Tidewater late Monday and this system might impact parts of southern New England Tuesday. A few runs of the Euro and American GFS earlier this week showed this storm achieving some sizable strength and thus delivering some rain and wind for coastal areas. Without any cold air however it was hard for me to get too excited about anything with this storm and it looks now as if the system will have a minimal impact on almost everywhere.

Vermont is expected to stay dry through most of next week but things will begin changing on the precipitation activity front as early as Friday of next week. This first potential system is the first product of some splitting in the stream and this could bring significant precipitation to all of New England in the Friday Dec 11 - Saturday Dec 12 time frame. There is a teeny tiny supply of cold air Thursday but not much to anchor it down and I am inclined to believe the best we can do from this is a period of ice.

Models diverge the week beginning December 14th with our hopes for anything exciting pinned more toward the progressively biased GFS ensembles which I am not inclined to believe right now. The American GFS breaks down much of the ridging in eastern North America by allowing the energized southern branch to undercut the vast area of upper level warmth. This would not be a particularly cold outcome with no arctic air delivery device but it would be stormy and with a little luck, some of this stormy would come in the form of snow. Both of the other medium range ensemble packages consolidate much of the energy in the west and thus show a very well defined trough west/ridge east outcome and potentially some record warmth in the east. I am not completely sold on this idea in spite of some consensus mostly because the undercutting scenario is plausible given the strength of the ENSO.

Sorry for all the crap news but ENSO's such as this years big El Nino are known for some horrendous periods and we might as well get this one out of the way in November/December and hope a long stretch of better times in January and February.

1 comment:

Manish Batra said...

Hey, very nice site. I came across this on Google, and I am stoked that I did. I will definitely be coming back here more often. Wish I could add to the conversation and bring a bit more to the table, but am just taking in as much info as I can at the moment. Thanks for sharing.
Power Wheelchair

Keep Posting:)