Hey, January — how about this year's no-show snow?
The month that, on average, sees 6.7 inches — and has been known to deliver some mega blizzards — reported just 0.9 inches this year at Long Island MacArthur Airport in Ronkonkoma.
At the root of it, climatologists say, is the mismatch between two main ingredients — cold enough air and precipitation.
In January “stations across Long Island had above-normal precipitation, but very little snow,” said Jessica Spaccio, climatologist with the Northeast Regional Climate Center, based at Cornell University. That’s as “most of the days with precipitation had above-freezing temperatures.”
Take the system starting late Jan. 19 that dropped a trace of snow at the airport. With the temperature rising to 35 degrees by midnight and then hitting 51 by noon of the 20th, further precipitation arrived as rain, 1.29 inches, she said. Had those temps remained below freezing, that could have amounted to around a foot of snow.
The month, punctuated on the final day with an icy blast, ended up 0.5 degrees above normal, with precipitation 0.21 inches above normal.
So, what accounts for that lack of January’s traditional cold?
Blame it on the weather pattern that from late November to early January saw the jet stream — a sort of super highway of fast-moving winds in the upper atmosphere — split into two branches, said Samantha Borisoff, also a climatologist with the regional center.
“The northern branch kept cold air locked up, while the southern branch brought in warm, moist air,” Borisoff said.
The pattern shifted around mid-January, bringing the storm track over the Northeast.
“While we got a couple of storms,” she said, “Long Island tended to be on the warm side of them; hence, a warmer, wetter, less snowy January than usual.”
Still, it certainly was a rarity. Since weather records started being kept there in September 1963, Long Island MacArthur Airport has seen only six previous Januarys deliver an inch or less of snow.
And, three-month snowfall totals — November through January — at Brookhaven National Laboratory amounted to 5.6 inches, the lowest amount since 2011 into early 2012, which came in at 5.5 inches.
As for what’s coming up, the Climate Prediction Center is showing strong confidence in probabilities for both higher than normal temperatures and precipitation, on average, from Feb. 5 to 9 for our area of the Northeast.
Of course, we could also keep a look out Saturday for Long Island’s four-legged forecasters-for-the-day, groundhogs Malverne Mel and Holtsville Hal. Six more weeks of winter or an early spring hinge on the sighting — or not sighting — of their shadows.
January snowfall at MacArthur Airport
2019 — 0.9 inches
2018 — 22.0
2017 — 14.0
2016 — 24.8
2015 — 30.2
2014 — 25.2
2013 — 3.3
2012 — 3.8
2011 — 34.4
2010 — 6.4
2009 — 8.9
2008 — 0.8
2007 — 1.0
Source: Northeast Regional Climate Center