Yesterday's weather was an insane mix of fog, sun, heat, rolling thunder, lightning, rain, and double rainbows. In NYC, we saw water being whipped out of rooftop pools in the evening, but in New Jersey and Long Island there was something a little more intense brewing in the ocean: a meteotsunami, which is apparently a very rare phenomenon.
According to the AP, the National Weather Service "says powerful thunderstorms created a small weather generated tsunami off the New Jersey coast known as a meteotsunami." Meteorologist Ryan Hanrahan noted on Twitter that the storm also created a little tsunami on Long Island Sound. He says this "occurred as a rapid fluctuation in pressure traversed the Sound at a speed that resulted in tsunami formation. The abnormal water fluctuations lasted a few hours in New Haven."
So what are these meteotsunamis? According to NOAA, they are "large waves that scientists are just beginning to better understand... driven by air-pressure disturbances often associated with fast-moving weather events, such as severe thunderstorms, squalls, and other storm fronts. The storm generates a wave that moves towards the shore, and is amplified by a shallow continental shelf and inlet, bay, or other coastal feature."
While they are rare, they have caused fatalities due to their strength and sudden nature, including in the Great Lakes, where in 1929, "a retreating 20 foot wave pulled ten people to their deaths at in Lake Michigan."
WNYC spoke to oceanographer David Hale, who works for the National Tsunami Warning Center, and he says "there's no need to panic... the water level rose just six to 12 centimeters, but that surge was caused by the weather as opposed to the wind or tides." However, "the tsunamis could have been dangerous if anyone had been in the water because of the strong current underwater." Hale also said it's okay to call these a "baby tsunami," though he prefers to call it "a low-amplitude tsunami." Baby tsunami it is.
This video contains footage of a meteotsunami from above: