Meteotsunamis Could Threaten Coastal Communities

Photo credit Buddy Denham/National Weather Service

As hurricane season gets underway, the National Weather Service is also making sure coastal communities are aware of the danger of meteotsunamis.

The Marblehead Police Department is among local agencies sharing some of this information on meteotsunamis, stating that as a coastal community, it is important to be aware of their dangers.

On June 13, 2013, despite clear skies and calm weather, tsunami-like waves crashed upon the New Jersey and southern Massachusetts coasts, according to the National Weather Service.

In New Jersey, three people were swept off a jetty and injured due to the waves.

The waves were captured by National Oceanic and Atmospheric Administration (NOAA) coastal water-level stations from Puerto Rico to New England as well as a Deep-Ocean Assessment and Reporting of Tsunamis (DART) buoy 150 miles offshore.

Due to the wave’s coincidence with a severe weather pattern and the lack of a detected earthquake or landslide, scientists deemed the event a “meteotsunami.”

The National Weather Service stated that the meteotsunamis should not be confused with storm surges caused by tropical storms.

“Meteotsunamis can generate waves as high as about 12 feet,” said Michael Angove, the NWS/NOAA Tsunami Program Manager. “These waves are capable of inflicting significant damage in coastal locations...particularly to unprepared ports and harbors. Meteotsunamis are somewhat unusual in that they can catch people completely off guard, since they will seem to appear ’out of nowhere.’”

These disturbances can generate waves in the ocean that travel at the same speed as the overhead weather system. Development of a meteotsunami depends on several factors such as the intensity, direction, and speed of the disturbance as it travels over a water body with a depth that enhances wave magnification.

Although these meteotsunamis pose risks worldwide, it is still a challenge to forecast them.

“Meteotsunamis are far more difficult to forecast than better known weather events such as tropical cyclones, Nor’Easters and even tornado outbreaks,” said Angove. “Meteotsunamis present a special challenge for forecasters in that they are generated only under a somewhat rare combination of circumstances that are not easily observable, much less forecastable.”

However, with recent increases in research as well as improved observational networks and forecast models,the National Weather Service states that a reliable forecast and warning system for the United States is within reach, and that the United States is in the early stages of developing a meteotsunami forecast and warning system.

“The National Weather Service is at the beginning stages of developing algorithms capable of identifying possible meteotsunami-generating disturbances,” said Angove. “Once we are able to do this, we would then look at producing operational forecasts, but this is likely 1-2 years out still. In the meantime, if we observe meteotsunami conditions forming, we have protocols in place to inform the servicing local Weather Forecast Offices of the potential threat”

More information on meteotsunamis from the National Weather Service is available here.