You can now read 10 articles in a month for free on BostonGlobe.com. Read as much as you want anywhere and anytime for just 99¢.

The Boston Globe

Metro

Safe to call storm a blizzard, weather service says

The results are in: It was the February blizzard of 2013. Kind of. In some places. Depending on who you ask.

For meteorologists, part of the excitement of the storm is the day-after post-mortem: Was it a blizzard or not?

Continue reading below

An official statement released Monday afternoon by the National Weather Service came close to settling the matter. It is safe, the weather agency said, to call it a blizzard in southern New England, with the caveat that in making a few blizzard determinations, “we also made some subjective decisions.”

Meteorological data ­revealed that in many spots across the region, blizzard conditions were reached: three straight hours of blowing or falling snow that reduced visibility to less than a quarter of a mile and winds that frequently gusted to 35 miles per hour or more.

Glenn Field, a warning coordination meteorologist at the National Weather Service in Taunton, said blizzard conditions do not need to be recorded at every weather station for a storm to merit the name.

“There aren’t any rules per se, as far as to how many sites” are needed, Field said.

“If a blizzard occurred at one spot, it would seem to me it was a blizzard,” and this was a blizzard at many spots, he said. Worcester, Norwood, New Bedford, Falmouth, and Newport and North Smithfield in Rhode Island, for example, all endured a blizzard, unequivocally.

Continue reading below

But a blizzard designation is not only a mathematical calculation based on wind speed and visibility data; judgment calls sometimes have to be made when towns are very close to reaching blizzard conditions or when meteorologists do not have all the data they need.

A dash of subjectivity is even present in the definition of a blizzard, which demands wind and visibility conditions must be “predominant” for three straight hours.

Boston had, during a six-hour span, four hours that met blizzard conditions, but only two of them were consecutive. And Manchester, N.H., met blizzard conditions for two hours and 40 minutes.

Did that count? Or was that just a really, really bad snowstorm?

David Epstein, who writes the “Weather Wisdom” blog on Boston.com, pointed out that you could call the storm a heat wave if you wanted, but people would still be shoveling out 2 feet of snow. His own assessment of the data? It wasn’t really a blizzard.

Observers at Blue Hill ­Meteorological Observatory called it an “impressive snowstorm” in their daily report, but not quite a blizzard.

Don McCasland, program director at the observatory, said that to most people, the fact that in the evening hours the wind speeds fell a little short of the blizzard bar would not matter.

For most people, “if you said, ‘No, this wasn’t a blizzard,’ they’d say you were ­insane, because they lived it,” McCasland said. “They’d say, ‘I know what a blizzard is, and this is a blizzard.’ And you’d have a hard time disputing it.”

Carolyn Y. Johnson can be reached at cjohnson@­globe.com. Follow her on
Twitter @carolynyjohnson.

You have reached the limit of 10 free articles in a month

Stay informed with unlimited access to Boston’s trusted news source.

  • High-quality journalism from the region’s largest newsroom
  • Convenient access across all of your devices
  • Today’s Headlines daily newsletter
  • Subscriber-only access to exclusive offers, events, contests, eBooks, and more
  • Less than 25¢ a week