JACKSONVILLE, Fla. -- Funnel clouds and water spouts moved from Mandarin up the St. Johns River, through downtown and north toward Nassau County late Friday afternoon, knocking out power to thousands of homes, snarling rush-hour traffic and giving thousands a view of nature's fury.

"Thing just was absolutely incredible developing and I watched it until it dissipated," motorist James Thompson told WOKV.

There were no reports of major damage, but there wires down, fires, street flooding and a boating incident near Orange Park.

A trained National Weather Service spotter first reported a funnel cloud 8 miles southeast of the University of North Florida about 5 p.m.

Moments later, a Department of Transportation camera at Interstate 95 University recorded what Channel 4 meteorologist Richard Nunn determined to be a water spout after the funnel moved over the St. Johns River. The slow-moving twister could be seen from the camera on Channel 4's Southbank tower for nearly 10 minutes.

Two other trained weather spotters reported the funnel cloud moving north over the river from Ortega toward downtown at 5 mph.

"Kind of dipping down into the river, it went back up. It went back down into the river and then finally it went back up," Jason Doyle said.

One caller said a water spout briefly came ashore at the Timuquana Country Club, then went back over the river.

Wires are reported down in San Marco and Lakewood and pea- to dime-sized hail was reported from Mandarin.

Heavy downpours made some roads temporarily impassable -- especially in Riverside and San Marco.

A transformer blew on Cedar Street, causing wires to arc and start a fire. Channel 4's Jennifer Bauer and photojournalist Matt James there to cover the storm were trapped in their car for 30 minutes. The fireball was so intense that it left a 3-foot hole in the ground.

Power outages of up to 8,000 homes were reported, but the JEA had already reduced the number of outages by 7 p.m.

Police closed the Hart and Fuller Warren bridges due to weather issues, but they were reopened by 6:15 p.m., the same time the tornado warning for Duval County expired.