A blizzard watch evolved into a blizzard warning, and close to 30 inches of snow fell on Long Island, frequently blowing, in some spots.

The nor’easter that claimed at least 45 lives on the East Coast and blew through these parts on Saturday, snarling road and rail traffic and inspiring hours of shoveling and countless Instagram photos, sure looked and felt like a blizzard.

Only it has not been officially dubbed one just yet.

To wear that crown, a storm has to have produced sustained winds or frequent gusts of 35 mph or more for at least three consecutive hours, along with heavy falling or blowing snow that’s led to visibility of less than a quarter of a mile, according to the National Weather Service.

All that has yet to be determined, with the verification process taking a while, requiring the review of hour-by-hour data from the area’s reporting stations, Long Island MacArthur Airport included, said Carlie Buccola, weather service meteorologist based in Upton.

Such was the case with a storm that, interestingly, happened to get its start a year ago Tuesday, the weather service said.

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The blizzard conditions were verified the following day, Jan. 27, based on measurements from Shirley, Long Island MacArthur Airport and Groton, Connecticut, the weather service said.

As Buccola points out, accurately assessing and analyzing all that information for a full-fledged storm report, possible blizzard moniker included, can be time-consuming.

Long Islanders may recall official blizzards from earlier years. Among them are those of Feb. 8-9, 2013; Dec. 26-27, 2010; Dec. 19-20, 2009; Dec. 6, 2003; and Jan. 7-8, 1996, said Jessica Spaccio, climatologist with the Northeast Regional Climate Center based at Cornell.