One thing you can say about the weather on Long Island in 2015 — there were some eye-popping swings: A record cold month, a record warm month, a massive snowstorm and a moderate drought.
Here are some of the standout events and conditions that defined Long Island’s year in meteorology:
- It took two years to the day, but it finally hit 90 degrees at Long Island’s official weather monitoring site on July 20, heading up beyond that to 94. That was after a no-90s stretch that started on July 21, 2013, making it the longest dearth of 90 or above since 1984, when records started being kept at Long Island MacArthur Airport in Ronkonkoma, according to the Northeast Regional Climate Center at Cornell University.
It was not that the warmer months were any cooler than normal, said Jessica Spaccio, climatologist with the center. It’s just that no one day had been hot enough to make it past 89 at the airport.
- Missing this year, to no one’s dismay, was an active Atlantic hurricane season, though for a tense day or so around Oct. 1, one of Hurricane Joaquin’s projected routes headed it toward the Northeast coast according to certain forecasting models. Instead, the storm veered well out to sea.
El Niño, a climate pattern that was well underway in the Pacific and affects weather worldwide, gets the thanks for the tame hurricane season. That’s because El Niño — which is still going strong — led to strong vertical wind shears and other elements in the Atlantic that “make it difficult for tropical storms and hurricanes to form and strengthen,” said Gerry Bell, lead seasonal hurricane forecaster with the National Oceanic and Atmospheric Administration’s Climate Prediction Center.
- As anyone with a lawn needing summer watering would know, starting in May, Long Island has been in moderate drought, according to the U.S. Drought Monitor.
As of day-end Sunday, the airport’s precipitation deficit for the year was 8.24 inches, making it the fourth-driest year at that point since 1984.
Dry conditions really took hold in April, which had just 38 percent of its normal precipitation, Spaccio said, followed by May, named the driest May on record with just 0.42 inches, which is 3.36 inches below average. The summer months also ended up drier than normal.
December so far is 0.67 inches above normal, thanks in part to last Wednesday’s system, which in all dropped 1.64 inches of rain at the airport.
Looking ahead, there’s a slight tilt — a 33 percent to 40 percent chance — toward above-normal precipitation for the January through March period, according to the Climate Prediction Center.
So stay tuned.
- New York City may have lucked out on the path of a strong nor’easter from Jan. 26 into Jan. 27, but not Long Island, with the East End seeing 50 to 60 mph gusts and 25 inches to 30 inches of snow.
Central Long Island registered 15 inches to 25 inches, Nassau up to 17 inches and Central Park just 9.8 inches, according to the National Weather Service. The city, where a state of emergency had been declared, was expecting snowfall akin to that of the East End, but the heaviest bands ended up developing farther to the east.
That, of course, meant that “Suffolk took it right on the chin,” which is how Gov. Andrew M. Cuomo put it at the time. At least one death on Long Island was attributed to the storm, with pre-storm driving bans preventing motorists from being stranded on highways, but with a massive dig-out to follow.
- It’s not often that weather similarities are drawn between Long Island and Caribou, Maine, which is near the Canadian border. But this year, thanks to a parade of Arctic air blasts, both locations had their coldest starts to February on record, the regional climate center pointed out at the time.
MacArthur ended the month with an average monthly temperature of 21.6 degrees, making it not only the coldest February in three decades, but also the coldest month overall. (Caribou came in at an average 2.8 degrees, making it the all-time coldest February in 76 years of record-keeping.)
Snow came along with the cold: The airport had 14.4 inches, 6.3 above normal for the month.
The mechanism behind the cold, cold and colder, meteorologists said, was a persistent pattern finding a ridge of high pressure over the West Coast, which led to the jet stream’s dipping down over the eastern U.S., bringing frigid air along for the ride.
- December’s on course to be the warmest December on record on Long Island. Temperatures Monday ended five-straight days of record-breaking highs, with 25 of the first 27 days seeing highs in the 50s or 60s, according to weather service data. The normal monthly high for December is 43 degrees.
As of day’s end Sunday, the average monthly temperature was registering 13 degrees above normal at 49.2 degrees, according to the weather service.
Such toasty temperatures in December, Spaccio said, are not uncommon during a strong El Niño, keeping the jet stream — a sort of superhighway of westerly winds — to the north, which holds colder temperatures at bay and allows warm, moist air up from the south.
Climate change is not a driver of the above-normal warmth, she said, but could make already high temperatures just a tad higher. It’s not unlike a baseball player on steroids, she said. The player “may have hit a home run without the steroids, but it probably wouldn’t have gone as far.”