The band of showers and thunderstorms prompted Suffolk officials to issue a tornado warning Tuesday night and a wind advisory that was to expire Wednesday at 6 a.m., officials said.
Tuesday's tornado warning was to remain in effectuntil 10 p.m.
Power outages were reported in both counties because of high winds and downed electric wires. The Long Island Rail Road reported delays on the evening commute because of downed trees.
Streets flooded and winds were expected to top 50 mph. The expected mix of wind and rain made conditions favorable for isolated twisters, said Joey Picca of the National Weather Service in Upton. "Once these storms come through, they can also produce wind gusts," he said, adding, "not widespread, but enough to bring down trees and power lines and heavy rains, making driving hazardous."
Throughout the day and into the evening, the effects of extreme weather were apparent.
Old Brookville police closed West Shore Road in Mill Neck from Mill Hill Road to Cleft Road and Piping Rock Road in Locust Valley from Frost Pond Road to Chicken Valley Road because of downed power lines.
The state Department of Transportation reported a tree down on the eastbound ramp at Exit 17S on the Southern State Parkway shortly after 5:30 p.m.
Arrivals at LaGuardia, Kennedy and Newark Liberty were averaging delays of two to nearly three hours, according to the Federal Aviation Administration website. No weather-related arrival delays were reported at Long Island MacArthur Airport.
Some departures were delayed, and the FAA advised travelers to check with their airlines about Wednesday's flights.
With Bill Bleyer, Zachary R. Dowdy and John Valenti