The tornado appears to have touched down between 8:28 and 8:31 p.m. in the northern part of Havana’s Boyeros neighborhood. The funnel then plowed east-northeast, passing just south of Havana Port and narrowly missing the National Capitol Building a mile and a half to the north. The circulation intensified, reaching its maximum strength about five minutes before exiting offshore into the Straits of Florida.
Doppler radar from the National Weather Service in Key West, Fla., shows the tornado’s signature funnel with strong rotation during the time the twister was on the ground.
The tornado spawned from a supercell thunderstorm, which has a rotating updraft. While waterspouts are a common sight in central Cuba, tornadoes are rare; the most recent one before Sunday appears to have occurred in May 2013.
Sunday’s storm formed on the south end of a 200-mile-long squall line that stretched northeast into Miami. The only place conditions were favorable for tornadoes to develop was the southern end of the squall line, sometimes referred to as the “tail-end Charlie.” It’s there that winds can rush in uninterrupted from the south, adding more energy to fuel the storm.
The radar scan at 8:37 p.m. also showed signs of large debris in the air. Radar can detect unnatural shapes in the atmosphere — jagged pieces of metal, shrapnel, wood and other building materials from destroyed structures.
Given the damage, a specialist at the Cuban Institute of Meteorology said the tornado was probably F4 on the Fujita scale, El Nuevo Herald reports. It appears to have been the strongest tornado to strike Cuba since December 1940, when an F4 tornado killed 20 people in the nearby town of Bejucal.