A massive storm is churning and has stalled over the western Atlantic Ocean, just offshore of the East Coast -- and it may acquire some tropical characteristics as it blasts New England with wind, cold air, rain and even wet snow late this week.
The overall structure of the storm is complex. Even though the system is producing cold rain and even occasional wet snow on its periphery, its core has warm characteristics, like that of a tropical storm.
|This image, captured at 11:30 a.m. EDT Thursday, shows an almost eye-like structure to the storm spinning off the New England coast. Photo courtesy of NOAA|
"There is a chance the storm could be dubbed a subtropical storm at some point into the end of the week," AccuWeather hurricane expert Dan Kottlowski said, adding that if it develops it will likely start to show signs on Friday or by Saturday morning.
A subtropical storm is a type of hybrid storm, showing both tropical and non-tropical characteristics, and can sometimes transition into a named tropical storm or hurricane. Subtropical and tropical systems are unusual but not unheard of outside of the official Atlantic hurricane season, which runs from June 1 to Nov. 30.
According to National Hurricane Center records, dating back to 1851, at least one named tropical storm or hurricane has occurred during every month of the year in the Atlantic. However, off-season systems are not common and do not develop every year.
There have been two named tropical systems in April, Tropical Storm Arlene in 2017 and Tropical Storm Ana in 2003. Arlene developed in the central Atlantic several hundreds of miles east of Bermuda as a subtropical depression and then intensified further to become fully tropical. At its peak intensity on April 21, Arlene had a small eye that was visible on satellite images.
Ana was the first tropical storm ever to form during the month of April after a cold front stalled well off the East coast, according to the NHC. Similar to Arlene, Ana first brewed into a subtropical storm and it did so on April 20, 2003, about 250 miles west of Bermuda, before it became fully tropical on April 21.
Satellite photos since Wednesday revealed that thunderstorms are circulating near the center of the feature currently spinning over the Atlantic, much like that which occurs in warm-core systems such as tropical storms and hurricanes.
Should the system be dubbed a subtropical storm, the first name on the list of the Atlantic hurricane season for 2020 is Arthur. The Atlantic storm will wobble a few hundred miles offshore into Friday night.
In this position, the potent storm will continue to generate gusty winds, cold rain and even some wet snow at times over New England into Friday night.
The steadiest rain will tend to fall over central and eastern New England, and there will be a chance for episodes of wet snow to bring a small, slushy accumulation to the ridges and peaks in the mountains.
"The persistence and strength of this storm has the sea agitated and large waves will pound the northern- and eastern-facing shoreline of New England and to some extent Long Island, New York," AccuWeather senior meteorologist Brett Anderson said. Waves well offshore of 15-25 feet will pose a risk for commercial fishing vessels.
"Beach erosion and minor coastal flooding at times of high tide will continue into Friday night, before subsiding this weekend," he added. The storm will finally drift away from the Northeast coast this weekend.
"The retreat of the ocean storm means good news for outdoor enthusiasts, as drier air will return along with sunshine and there will also be much less wind compared to that of Wednesday, Thursday and Friday," Anderson said.
|Drier air will arrive across the Northeast this weekend, but it is not expected to be accompanied by a significant warmup. "A bigger warmup will be more directed west of Appalachians," Anderson said.|
However, the air will remain cool, especially across New England and eastern New York state, including the New York City and Long Island areas. The nights and mornings will be chilly this weekend.
"As the afternoons try to warm up with the April sunshine, there will likely be a chilly sea breeze pushing inland along the coast from Maine to New Jersey both days," Anderson added. The effect of the sea breeze will be to keep those coastal areas several degrees lower than farther inland.
"Despite the cool air lingering, the sunshine should feel quite nice for those going outside for a walk during the middle of the afternoon," Anderson said.