NEW YORK - Powerful thunderstorms slammed the New York area on Tuesday afternoon and evening, triggering alerts about potentially dangerous flash floods.
The National Weather Service issued Severe Thunderstorm Warnings and Flash Flood Warnings for several counties in New Jersey and New York.
"Doppler radar indicated thunderstorms producing heavy rain approaching the warned area. Flash flooding is ongoing or expected to begin shortly," NWS said in an alert. "Flooding of small creeks and streams, urban areas, highways, streets and underpasses as well as other drainage and low lying areas."
The Flash Flood Warnings have since expired.
Notify NYC sent an alert urging New Yorkers to prepare for the severe weather.
"Strong winds can cause flying debris, turn unsecured objects into projectiles, and cause power outages," Notify NYC stated. "Do not drive your car into areas where the water covers the roadway. The water depth may be too great to allow your car to cross safely. Move to higher ground."
FOX 5 NY chief meteorologist said this type of weather could return on Wednesday.
What Is a Severe Thunderstorm?
A "severe thunderstorm" is a storm that produces 1-inch hail or larger and/or wind speeds of 58 mph or faster.
"Severe thunderstorms can produce tornadoes with little or no advance warning," NWS states. "Lightning frequency is not a criteria for issuing a severe thunderstorm warning."
The NWS issues a Severe Thunderstorm Watch when conditions are favorable for the development of severe thunderstorms.
"They are normally issued well in advance of the actual occurrence of severe weather," NWS states. "During the watch, people should review severe thunderstorm safety rules and be prepared to move to a place of safety if threatening weather approaches."
The NWS issues a Severe Thunderstorm Warning when either radar indicates a severe thunderstorm or a spotter reports a severe thunderstorm (see definition above). Therefore, if you're in the affected area, you should seek safe shelter immediately.