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Multiple tornadoes whirled through the Sunshine State overnight Wednesday into early Thursday, causing damage and destroying several structures. More tornadoes were possible during the daylight hours Thursday, with a tornado watch in effect for the northern half of the Florida Peninsula until 3 p.m.

The strongest tornado hit the communities of North Clearwater Beach, Dunedin and Palm Harbor. That’s where one woman awoke to the roof and walls of her home crashing in on her, according to the Clearwater Police Department. She was not injured.

Farther north, one condominium was destroyed in a residential complex while the others were unscathed, attesting to how narrow the tornadic vortex was at one point.

A tornado also hit Fort Island Trail in the town of Crystal River, about 60 miles north of Tampa. It’s possible that other tornadoes touched down as well, but they have yet to be confirmed by the National Weather Service. A total of 32 tornado warnings were issued as a pair of rotating supercell thunderstorms tracked across the entire peninsula, the first from Crystal River to Palm Coast and the other from north of Tampa Bay to Daytona Beach.

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About 14,000 electricity customers remained without power early Thursday, according to PowerOutage.us.

Clearwater Beach tornado

The greatest overlap of instability, or storm fuel, and wind shear, or changing winds with height, was predicted to exist near the Gulf Coast of Florida. That’s where warmth and moisture from the ocean would further help to juice up the atmosphere and make tornadoes a possibility.

Shortly before midnight, a string of thunderstorms materialized offshore. All were rotating or supercell storms, but eventually a couple of dominant cells became established.

At 1:37 a.m. Eastern time, a very strong waterspout — or tornado over water — was in progress offshore of Clearwater. Intense rotation was present (left), as was a BWER, or “bounded weak echo region” on radar. That’s a small doughnut hole that marks where the waterspout’s upward motion was so strong that rain was unable to fall.

Know someone in Clearwater, Dunedin or surrounding areas? You might want to wake them up. There’s strong rotation just west of Belleair that will move onshore soon. Can’t rule out a #tornado. #FLwx pic.twitter.com/E7hfuu3OlT

Ultrasensitive terminal Doppler radar from Tampa’s airport revealed rain swirling around the tornadic waterspout, tracing the rotational “hook echo.” A tornado warning was issued at 1:41 a.m. when the tornado was “located just offshore,” allowing residents mere minutes to get to shelter.

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Multiple webcams captured the tornadic waterspout as it moved ashore, including one at the Wyndham Grand Hotel in Clearwater Beach. About 22 seconds into the video below, notice a smaller needle-shaped waterspout barely visible behind the lead vortex:

That’s likely what meteorologists refer to as a “satellite vortex,” or a smaller whirlwind that forms on the flank of and orbits a more powerful tornado. It’s probable that the circulation was at its strongest when it was still offshore.

Still, the tornado flipped vehicles in Dunedin and damaged buildings.

Before the main tornado event, an earlier supercell produced a funnel cloud that was spotted near State Route 54 at Little Road in Holiday at about 12:15 a.m.

Why the tornadoes formed

Tropical low pressure became strung out along a front draped across the northern Gulf of Mexico during the midweek period. That allowed waves of moisture, in the form of showers and thunderstorms, to propagate east-northeast into Florida and the Southeast.

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Ahead of the system, winds near the ground were out of the southeast. That enhanced low-level helicity, or spin, and contrasted against southerly, southwesterly and westerly winds at higher altitudes. The subsequent wind shear allowed thunderstorms that spanned multiple layers of atmosphere to rotate.

If we review data from a weather balloon launch from Tampa at 8 p.m. Wednesday, we can see the robust change of winds with height. Notice the wind barbs on the right:

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