ADDISON COUNTY — According to data from the Burlington office of the National Weather Service, up to two feet of snow fell on Addison County in the storm earlier this week, far more than six to 10 inches forecasters had initially expected.
NWS monitors called in amounts that ranged from 21.7 inches in South Lincoln to 24 inches in both Bridport and the north end of Lincoln.
Elsewhere in the county, reporters to the NWS measured 23.8 inches in Salisbury, 23 in Salisbury, and 22 in Cornwall.
The NWS does not collect annual snowfall data for Addison County, but the two feet of wet, heavy snow that fell in Burlington brought this winter’s total there to 124.3 inches as of Tuesday afternoon. A couple more inches were expected on Thursday before the precipitation changes over to rain.
That Tuesday amount makes the winter of 2010-2011 already Burlington’s third snowiest of record, surpassing the 122.5 of 2000-01 and 120.2 of 2007-2008.
NWS forecaster Brooke Tabor said this winter has Burlington’s No. 2 spot in its crosshairs: In 1886-87, 132 inches fell.
This winter will move into second place “if we have a normal spring,” Tabor said. In March, Burlington’s average snowfall is 13.6 inches, and in April the average is 4.0.
Given that more than a week of March is gone, another foot or so is statistically likely, he said, an addition that would push this winter’s total to about 136 inches.
Tabor believes the all-time record of 145.4 inches that dates from 1970-71 is probably safe, given that this winter lacked a big December head start.
“We have a good chance of passing the 132. The 145 may be a little far from reach, “ he said. “It’s always possible ... but I think we’ll fall short of that.”
Too many unusual factors would have to fall into place to create more major snowfalls, Tabor said.
On the other hand, he acknowledged this winter “has been far from normal.”
Tabor said the west-to-east flow of wind known as the jet stream has been unusually volatile, fueled by a more-active-than-usual duel between cold polar air from the north, and warm, moister-than-typical sub-tropical air from the south. He described the ongoing clashes between the air masses as a “battle zone.”
At the same time, waters in the Gulf of Mexico and southern Atlantic Oceans have warmed, fueling not only that tropical air over the southern U.S., but also regular low pressure systems along the Eastern seaboard.
Many weather systems have slammed coastal states this winter, Tabor said; some have missed Vermont, while others have drifted far enough north to dump snow.
“This has been one of the most active seasons I’ve seen,” he said.
If local residents have had the impression sunlight has been scarce, it has been for good reason. Daytime temperatures have been slightly colder than normal, according to NWS figures, because of persistent cloud cover. But nighttime temperatures have been slightly warmer because clouds have prevented radiational cooling.
Overall, average temperatures have resulted.
“In the long run, it’s pretty much a normal temperature (average),” Tabor said.
At the same time, Tabor acknowledged that if Vermonters have noticed forecasts have been less than 100 percent accurate, it has also been for good reason.
Part of the challenge for meteorologists is always to determine how a storm will track as it moves eastward across the country. With the unusual volatility of the polar and tropical air masses pushing from opposite directions, storms’ paths have been unpredictable.
“It’s been a difficult forecast getting the tracking right,” Tabor said.
Andy Kirkaldy may be reached at firstname.lastname@example.org.