Think Snow, Tweet Snow !!!

Thursday, March 8, 2007

Riding the March roller coaster: Record cold Friday morning and then a thaw next week

The SCWB is getting a little dusty and an update is greatly needed. The month of March never ceases to amaze me. Statistically, it is one the noisiest months of the year in New England where temperatures have fallen to -25 F and have risen to as high as 70 F. The recent outbreak of cold has been historic, shattering records all across the state of Vermont by several degrees and even approaching historical lows for March in some instances. Several more records will get broken Friday morning as temperatures, once again fall to -20 F in some areas before warming into the 20's Friday afternoon. There is no need for the cold wax this weekend however. The temperature moderation Friday afternoon will be the beginning of a more signifcant trend, eventually evolving into our first real thaw of 2007. I suppose I should re-state since its our first real thaw since those disastrous first two weeks of January.

The Telefest Details
The weekend as it turns out, although significantly milder than the recent days, will not be as mild as once was expected (like my last update). Temperatures will start out in the teens and quickly rise to freezing and even a few beyond by the early afternoon. The high sun angle and the warmer temperatures will be enough to soften the snow, particularly at the low elevations but we should see an increase in clouds and eventually a full overcast by the middle of the afternoon. The precpitation which should arrive late in the day on Saturday is not likely to be snow but either rain, freezing rain, ice pellots or sleet depending on the excact location. It should be a rather short-lived round of precipitation, whatever falls, which will end as a bit of snow or flurries. Sunday appears mostly dry with temperatures in the 20's at the beginning of the day and 30's during the afternoon.

Signs of spring next week
The Arctic Oscillation index (AO) will surge to a big +2 next week and the Jet Stream will respond by tightening and becoming both very fast and very zonal. In addition to this is the trough which is expected to re-amplify across Western Canada. This would be a very sinister conspiracy if it were mid-winter but our big base should combine well with the warmer weather to make for some nice skiing. And I can say with growing confidence that it will get warm. NWS Burlington is saying low 40's which covers mainly the valley locations for Tuesday and Wednesday. At the MRG base, I would not at all be surprised to see temperatures climb into the 50's during the afternoon on at least two occasions between Tuesday and Friday. The best news with the warm weather involves the precipitation which will be minimal through Thursday. On Friday, a well organized storm system, fueled by a strengthing trough in the middle of the country may bring significant rain to the region followed by colder weather for the weekend of the 17th and 18th but its difficult to say for sure. If we do get rain accompanied by wind late next week, it will eat away at the base significantly but again, this hypothetical storm may never materialize or evolve differently relative to current model guidance.

Some cold/snow returns by next weekend
Ensembles erode the big trough in B.C./Alberta by the 17th and 18th and suggest that a large ridge develops across the western United States. The AO's big surge next week is also expected to be temporary in nature and a move back to neutral combined with the manifestation of the western ridge will allow for a return to colder weather and some new snow to go along with that after the 17th. All that being said, there is no strong signal for any sustained pattern of an anomalous nature. If colder and snow were to return on or just after the 18th, it may again be followed by another round of milder weather.

The Quick Summary
Record cold Friday morning but then some big changes and a thaw next week.

No comments: