Tuesday, December 9, 2008

Horizon is now littered with trouble

As there now is a building consensus for a well defined western trough and an equally well-defined eastern ridge. This folks is a problem since the Great Lakes are unfrozen and when combined with an ill-favored pattern can make our access cold weather very limited. So a few days ago it looked like we would be dealing with one or two rogue intruders and it now looks like we will be playing defense against a well-coordinated battalion. A strong western upper level trough should be expected from time to time this winter given the negative state of the PDO. Furthermore, our friends out west have been hurting so far this winter as the season has started out both warm and very snowless. Check out the lack of snow across the interior west, a rare sight to have such a widespread area of the mountain-west snowless.

http://www.natice.noaa.gov/pub/ims_gif/DATA/cursnow_usa.gif

The rain on Wednesday is likely to end as snow as cold makes a southward push into northern Vermont late in the day. Clouds will remain in place as a second area of low pressure organizes itself in the southeast and makes a run at New England late in the day. The american model has been generally consistent that precipitation in northern and most of central Vermont falls in the form of snow Thursday night into early Friday and forecasts from the National Weather Service are suggesting as much. The American model at face value suggests that snowfall will be in the 6-10 inch range prior to Friday but the American model is not the only apple on the tree. Alternative model guidance from Europe is suggesting a much warmer system where precipitation is mostly falling in a form other than snow. The European model is the preferred guidance in this time frame so one has to take it seriously and at least assume a compromise and a hybrid system including a mix of snow and sleet for Friday December 12th with total accumulations of only a few inches. There at least remains the potential for decent storm going into what could be opening day so we will wait and watch and hope for some good news.

Flurries Friday and colder weather will be followed by dry and cold weather Saturday. Daytime temps will be in the teens and 20's while low temperatures Friday night will be in the single numbers. Sunday should see a return of milder weather with temps approaching the 30 degree mark. The chances for a powder day over the weekend appear slim however as the atmosphere will quickly stabilize in the wake of our Thursday night weather system.

The week beginning the 14th and ending the 20th is starting to look a bit ugly. The push of very mild air for early next week appears ferocious now and will cover much of the St Lawrence Valley along with all of interior New England by later Monday. At this point our best hope is to limit any rainfall that may arrive in the middle of the week with the incoming cold front. Cold weather arrives toward the middle of the week but its arrival may very well be followed by a quick departure as another surge of mild air threatens to bring more precipitation of a mixed or rainy variety by the 19th and 20th. It appears to be a potentially very lousy weather pattern going into Christmas and we will have to hope that the eastern ridge can get flattened just enough to lower the storm track a few hundred miles. It looks much more adverse today yes, but we did have a few such patterns last year (a negative PDO year) to contend with. For the most part we contended successfully and I can recall specifically how bad the week following the Super Bowl appeared and it turned abruptly and dramatically and we made out very well. Furthermore we do have a substantial amount of very cold weather in Canada and a slight shift here or an undulation there could allow the mountain to put our latitude to good use.

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