Incredible Video From Space Shows Lightning Strikes Inside Hurricane Dorian

A meteorologist has created a fascinating animation which shows numerous lightning sparks occurring in Hurricane Dorian's outer regions. Dakota Smith—a scientist from the National Center for Atmospheric Research—put together the short video loop using several layers of data collected on Tuesday by satellites.

Lightning is very common in the outer portions of hurricane storm systems, Oliver Claydon, a spokesperson for the U.K. Met Office, told Newsweek. "There is immense energy in a hurricane which can cause very frequent lightning strikes."

in fact, observational studies indicate that an average of around 4,400 flashes occur within the centers of hurricanes per day, according to Jian-Feng Gu, a meteorologist from the University of Reading in the U.K.

Lightning in tropical cyclones—a term which refers to hurricanes, typhoons, tropical storms, and other related phenomena—forms in much the same way that it does in an ordinary "convective" thunderstorm.

"As tiny water droplets form inside a storm cloud, they are propelled towards the top of the cloud by strong internal winds (updrafts) where they turn to ice," Claydon told Newsweek. "Some of the pieces of ice grow into hail, but others remain very small. Some of the hail that forms becomes too heavy to be propelled by the updrafts and so begins to fall back through the cloud, bumping into smaller ice particles as they do so.

"During these collisions, electrons are transferred to the hail giving the hail a negative charge, while the ice particles that have lost electrons gain a positive charge," he said.

The updrafts continue to carry the ice particles upwards, giving the top of the cloud a positive charge. Meanwhile, the hail continues to fall through the lower part of the cloud, giving it a negative charge.

"As well as being attracted to the positive charge in the top of the cloud, the surplus of electrons in the cloud base are attracted to positive charge in other clouds and on the ground," Claydon said. "If the attraction is strong enough, the electrons will rapidly move towards the positive atoms. The path they make in doing so forms the channel we see during a flash of lightning.

"As negative charge builds at the base of the cloud, the electrons near the ground's surface are repelled," he said. "This leaves the ground and the objects on it with a positive charge. As the attraction between the cloud and the ground grows stronger, electrons shoot down from the cloud cutting through the air at around 270,000 miles per hour."

Intriguingly, some research suggests that the number of lightning strikes is linked to the intensity of the hurricane. So, as the energy or intensity of a hurricane increases, it can be expected to produce more lightning.

However, the inner cores of tropical cyclones—within about 60 miles of the center—produce surprisingly little lightning, according to the National Oceanic and Atmospheric Administration (NOAA.) For example, only about a dozen cloud-to-ground strikes occur per hour on average around the eyewall of a tropical cyclone.

The graph below, provided by Statista, shows the cost of damage by weather incidents worldwide over the past 20 years.

Economic cost weather damage statista
Global economic losses caused by weather events. Statista

This lack of lightning in the inner core is potentially due to the fact that the eyes of tropical cyclones tend to be warmer than the air just above the ocean, which results in weaker updrafts. This in turn means there is a lack of super-cooled water that is key to charging up the storm and producing lightning.

"Lightning activity is usually weaker in hurricanes than in intense convective mesoscale storms that affect large mid-latitude continents in the summer," Philippe Lopez, from the European Centre for Medium-Range Weather Forecasts, told Newsweek.

"A possible explanation for the smaller number of flashes commonly observed in the inner region of tropical cyclones (eyewall) is the relative weakness of updrafts in this region," he added. "This is because tropical cyclones possess a deep warm core, where the atmosphere is much less unstable than in mid-latitude convective systems. Higher lightning activity can be observed in the outer convective rain bands of tropical cyclones, where atmospheric conditions are closer to that of mid-latitude thunderstorms."

Research suggests that increases in lighting strikes around the eye of the storm indicate strengthening, thus providing a useful forecasting tool.

After battering the Bahamas for two days—causing catastrophic destruction and at least seven deaths—Dorian is located around 80 miles east northeast of Cape Canaveral, Florida. It is moving north-northwest at around 7 miles per hour, as of 2 a.m. EDT, according to forecasters.

At present, the storm—which has weakened to a Category 2 on the Saffir-Simpson Hurricane Wind Scale with maximum sustained wind speeds of 110 miles per hour—is not expected to make landfall in the U.S. Instead, the National Hurricane Center (NHC) believes it will likely stay just off the U.S. eastern seaboard as it tracks northwards.

This article was updated to include additional comments from Philippe Lopez.

Hurricane Dorian, lightning
Screenshot from an animation showing lightning in Dorian's outer bands. Dakota Smith
Incredible Video From Space Shows Lightning Strikes Inside Hurricane Dorian | Tech & Science