Long Islanders have a fairly good chance for milder than normal temperatures seen of late to continue, on average, right through July, long-range forecasters say.
For May, there’s a 40 percent to 50 percent probability for above average temperatures in the section of the Northeast that includes Long Island, according to Thursday’s outlook from the Climate Prediction Center, which is under the umbrella of the National Oceanic and Atmospheric Administration. Make that a 50 percent to 60 percent probability for the May through July period.
Among the factors behind that call are the continuing, though weakening, El Nino climate pattern in the tropical Pacific; warmer ocean temperatures in much of the North Atlantic; and climate prediction models that are “overwhelmingly consistent” in indicating warmer-than-average, said Jon Gottschalck, chief of the center’s operational prediction branch, during a Thursday media call.
That, of course, does not mean there wouldn’t be some dips now and then, said Jessica Spaccio, climatologist with the Northeast Regional Climate Center based at Cornell University.
“That’s usually how the weather works, with ups and downs throughout the month,” Spaccio said.
Average monthly temperatures for Long Island MacArthur Airport are 58.6 degrees for May; 68.4, June; 73.9, July.
Milder temperatures were interrupted this month with a brief cool spell, resulting in the average, as of day-end Wednesday, registering slightly below normal. March, however, came in at 6.2 degrees above.
As for precipitation, at this point indicators for the period through July are showing an equal chance for above, below or right at normal, the center said.
Also discussed Thursday was the weakening El Nino, the Pacific climate pattern that starts with warming sea surface temperatures and influences weather around the globe, as well as its flip side, La Nina.
The center is looking at a close to 60 percent probability for La Nina to be brewing in the July-August-September period – make that close to 70 percent for September-October-November.
Still, Gottschalck said that making any call as to its potential strength was premature.
That’s of interest, as Atlantic hurricanes – the official season runs from the first of June through the end of November — have an easier time forming with La Nina conditions — which get started with cooler than normal Pacific waters - as opposed to with El Nino, when associated vertical wind shear is more of a suppressor.
Indicating “large uncertainty” so early on, Colorado State University researchers on April 15 did say they’re anticipating near average hurricane activity this year, with the prediction center scheduled to release its outlook on May 27.