The National Weather Service (NWS) office in New York said the thunderstorm whirlwind moved over the Harlem River around 2:30 p.m. in the afternoon, south of the Broadway Bridge that connects Northern Manhattan with the Bronx.
The gustnado then hit the shoreline of the Bronx before dissipating north of Fordham Road, according to forecasters.
Radar velocity estimates and a wind observation of 71 mph from Fordham in the Bronx indicate the gustnado had estimated wind speeds of between 70 to 75 mph.
According to the National Oceanic and Atmospheric Administration (NOAA), a gustnado is a small, whirlwind which forms as an eddy in thunderstorm outflows.
The whirlwinds are classified as thunderstorm wind events, and like dust devils, "some stronger gustnadoes can cause damage," according to the agency.
Video obtained by WNBC-TV shows the gustnado as it made its way over the Harlem River.
The NWS said that a severe thunderstorm warning was initially issued for the area around 2:12 p.m. as the line of storms approached, with strengthening detected in radar prompting forecasters to upgrade it to a tornado warning by 2:33 p.m.
"At this point though, observational evidence is inconclusive of a tornado touchdown," the NWS stated on Wednesday.
The powerful line of thunderstorms also caused damage in neighboring New Jersey, where wind gusts were reported between 60 to 80 mph.
Numerous homes in Toms River were damaged and trees were downed when the thunderstorms struck.
The Toms River Police Department said on Facebook over 100 calls were received for fallen trees on houses and cars, wires down, traffic signals out, and destroyed property.
Forecasters from the NWS office in Mount Holly, N.J. concluded that the damage was caused by straight-wind lines associated with thunderstorms moving rapidly towards the coast, and not a tornado.
“Small-scale circulations were seen and recorded immediately ahead of the advancing cold front, which in some cases induced waterspouts over a few back bays and oceanfront areas, but were not strong enough to cause the damage experienced by numerous communities across the state,” forecasters said.