A cruel winter for forecasters

Been there, done that. Alex Neff, of East Pikeland, Chester County, digging out his two cars on Feb. 13. It probably wasn't the last time.
Been there, done that. Alex Neff, of East Pikeland, Chester County, digging out his two cars on Feb. 13. It probably wasn't the last time. (STEVEN M. FALK / Staff Photographer)

"We have a lot to learn," one said of the brushes with the polar vortex. And it might not be over yet.

Posted: March 24, 2014

Although the arrival of the vernal equinox has been confirmed, the S word has managed to creep into the forecasts for this week.

And it isn't spring.

"Let's hope they are wrong," said Tomasz Anisko, curator of plants at Chester County's Longwood Gardens, noting that the region's blooms and blossoms are up to two weeks behind. Some, like camelias and wintersweet, may be lost for the season.

"I've been ready for spring for some time," Anisko said.

Snow is possible Tuesday, forecasters said, but even if it doesn't appear again before winter concedes to the realities of the calendar, a standard for persistent torment already has been established.

For the fourth straight month, March snowfall has been well more than double the long-term average.

Philadelphia has one of the oldest weather archives in the nation. Century-old hourly observations written in monasticlike script still reside in crumbling black books at the Franklin Institute. But never has it recorded four months like this officially.

The Philadelphia seasonal total, 67.6 inches of snow, is No. 2 in the 130-year period of record. New Jersey has spent a record $117.3 million on fighting snow and ice this season, said Steve Shapiro, spokesman for the New Jersey Department of Transportation.

Across the river, its Pennsylvania counterpart set a salt-spreading record, 172,368 tons, said spokesman Eugene Blaum.

And if anyone saw this coming, the secret was well-guarded. This has been a season as scarring to the seasonal forecasts as it has been to the road surfaces.

"We had a rough winter, too," said John Gottschalck, chief of forecast operations at the government's Climate Prediction Center.

The winter has been one long coming-out party for the "polar vortex," a swirling mass of frigid air rescued from eons of obscurity by a storm of media attention.

The vortex develops every winter over the Arctic, and periodically its influence expands into the United States. This year, however, it became unusually "elongated," and its southern extent has made frequent visits into the Philadelphia region, said Judah Cohen, seasonal forecaster for Atmospheric and Environmental Research (AER), a unit of Verisk Climate, based in New England.

"It was like Groundhog Day," he said. Cohen, who joined AER in 1998, said the behavior of the vortex "seemed unique" in his experience. AER had called for a mild winter in the East.

Surprisingly, the upper-air patterns over the North Atlantic, which typically govern weather in the East, were more favorable to a mild winter.

"We have a lot to learn," said Gottschalck.

The prime drivers of cold and snow have been areas of higher pressure, or ridges, across western North America, he said. In response, counterbalancing areas of low pressure, which favor cold and storminess, have persisted over the East.

"We don't really understand why that pattern has set up," Gottschalck said, adding that it might have been related to storminess in the tropics or unusally warm sea-surface waters in the eastern Pacific.

"We keep discovering new pieces of the puzzle," said Jon Nese, former meteorologist at the Franklin Institute and now at Pennsylvania State University. "But we still don't know how to fit those pieces together."

As to whether we are witnessing a climatic sea change, Nese urged caution. The period of record dates to the 1870s, he said, and some evidence suggests that winters of the 1830s rivaled this one.

If that's the case, Longwood's Anisko is perfectly happy to have missed that era.

He said the duration of snow cover, rather than the temperatures, has challenged the region's plant life.

Lingering snow, which repels the sun, has chilled the soil, and that has stressed the bulb plants, he said.

He does predict, however, that some day soon a reward is coming. Once the inevitable warmup gets cooking, nature will turn off the mute button, and the trees and flowers will explode with color.

Said Anisko, "We should be ready for a fabulous spring."


REGIONAL WINTER RECORDS

Philadelphia has set several snow records this season. They include:

Gold Medalists

4

Storms of 8 inches

or more

4

Months with snowfall

at least twice the norm

172,368

PennDOT Philadelphia region salt usage, in tons

$117.3M

NJDOT snow-and-ice expenditures

Silver Medalists

67.6

Seasonal snow total,

in inches, No. 2 in

130 years of records

14

Number of days with

at least 1 inch of snow, tied for second

with 1898-99

Daily snow records

March 17: 4.7 inches

Jan. 21: 11 inches

Jan. 3: 3.4 inches


610-313-8210

twood@phillynews.com

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