COCOA BEACH (FloridaToday.com) - A 15-year-old boy suffered a head injury Sunday afternoon when a "gustnado" swirled across the sand near Coconuts on the Beach, Brevard County Ocean Rescue Assistant Chief Eisen Witcher said.
The whirlwind sent umbrellas and other debris flying about 3:20 p.m. near the end of Minutemen Causeway.
Witcher estimated roughly 800 to 900 beach-goers were in the general vicinity, enjoying a summer weekend afternoon. He had just pulled up at Coconuts on the Beach on an ATV, and he said he watched the unexpected funnel take shape and move offshore over the ocean "from beginning to end."
"The wind picked up very intensely, very quickly. Then you saw umbrellas, kayaks, pop-up tents - you name it - start lifting into the air 40 to 100 feet above the ground," Witcher recalled.
"You're talking about Coconuts on a highly populated day," he said. "Everybody hit the ground. Some weren't so fortunate and got hit by flying debris."
The injured boy was struck in the head by a flying canopy and transported by ambulance to Cape Canaveral Hospital.
Sunday, the Melbourne National Weather Service station confirmed via Twitter that the wind event was a gustnado, a vortex similar to a dust devil.
"It's a small whirlwind that usually forms at an outflow boundary, which is wind coming off the front side of a thunderstorm. Unlike a tornado, a gustnado is not connected to the clouds up above - it's a ground-level phenomenon," said Amanda Bowen, a meteorologist.
"A gustnado is a quick spin-up that results from turbulence. This was a obviously well-documented one. They're not super common here, but they're not at all unheard of," Bowen said.
NWS meteorologists also tweeted a video of the gustnado that was filmed by Adam Libert, a 23-year-old Massachusetts Institute of Technology graduate student who was relaxing with friends on the beach a couple blocks to the north.
Libert said he was taking photos of ominously swirling, low-lying clouds when he spotted the gustnado. His footage shows umbrellas being hurled hundreds of feet out to sea while children scream nearby.
"You could see a little cyclone - sand flying in the air, a definite vortex. It went through the pack of umbrellas and people near Coconuts," Libert said.
Witcher estimated the gustnado spun across the sand for 10 to 15 seconds, then moved onto the ocean for another 20 to 25 seconds.
Lifeguards evacuated the beach after the gustnado struck, and Cocoa Beach police, beach rangers and firefighters reported to the scene. The lifeguard tower off Minutemen Causeway blew over amid the whipping winds.