Last Updated Jun 6, 2016 9:35 PM EDT
TAMPA, Fla. -- Residents on Florida's Gulf coast filled sandbags, schools closed early and graduation ceremonies were postponed as Gov. Rick Scott declared a state of emergency just before Tropical Storm Colin began drenching the state Monday, threatening serious flooding.
Rain and gusty winds from the storm have already begun to pelt the state's west coast, reported CBS Miami.
At 11 a.m., the center of the system was about 285 miles west-southwest of Tampa. It was moving to the north-northeast at 16 mph with maximum sustained winds of 50 mph. Tropical-storm-force winds extend outward up to 230 miles to the southeast of the center.
Heavy rains from the storm hit north Florida and southern Georgia on Monday, knocking out power in some areas and flooding roads on the Gulf coast.
Residents filled sandbags, schools closed early and graduation ceremonies were postponed.
A large portion of Florida's western and Panhandle coast was already under a tropical storm warning when the National Hurricane Center announced that a swift-moving depression had become a named storm. The center said it is the earliest that a third named storm has ever formed in the Atlantic basin. Scientists warned back in May there were likely to be more named storms this year than the past few.
Colin is forecast to take a turn toward the northeast with an increase in forward speed on Monday. A rapid northeastward motion is expected Monday night and Tuesday. On this track, the center of Colin is forecast to approach the coast of the Florida Big Bend area Monday afternoon or evening and move across portions of Florida and southeastern Georgia early Tuesday morning.
Little change in strength is forecast during the next couple of days.
Early Monday, Ronald P. Milligan, 74, stopped by a park in St. Petersburg where authorities planned to distribute sandbags because the ditch in front of his home had filled during the previous evening's rain.
"If last night was a 'no storm' -- and the water was almost up to the hump in my yard - I'm worried," Milligan said, motioning to about knee level. He's lived in Florida since the late 1970s and hasn't ever prepared for a storm this early.
Sandbags also were being distributed in Tampa and nearby cities.
Schools in at least one Florida Gulf Coast county were dismissed early Monday, and two high school graduations in the Tampa Bay area were postponed due to the storms, with both ceremonies being moved to Wednesday night and Thursday. Winds from Colin also closed the Sunshine Skyway Bridge in Tampa.
In addition, two high school graduations in the Tampa Bay area were postponed due to the storms, with both ceremonies being moved to Wednesday night and Thursday. Winds from Colin also closed the Sunshine Skyway Bridge in Tampa.
Farther north at Cedar Keys National Wildlife Refuge, the storm's arrival this afternoon was due at the same time as high tide, creating even higher risk of severe flooding, said Andrew Gude, manager of the refuge for the U.S. Fish and Wildlife Service.
"We're taking chain saws home so we can cut our way out of our neighborhoods and cut our way back into work tomorrow," Gude said.
Not everyone in Florida was hunkering down.
About 50 people were in the water with surfboards off Treasure Island to take advantage of the rare 2-3-foot swells breaking in the Gulf's warm waters.
"It's like man against nature," said Derek Wiltison of Atlantic Beach. "Surfers tend to drop what they're doing -- work, relationships, whatever -- to go out and catch a wave."
One woman in St. Petersburg, Florida, took advantage of the storm in a mermaid costume.
Colin is expected to produce rainfall amounts of 3 to 5 inches, and forecasters said up to 8 inches are possible across western Florida, eastern Georgia and coastal areas of the Carolinas through Tuesday.
Forecasters also described Colin as a lopsided storm, with tropical storm-force winds extending up to 185 miles east of its center.
A tropical storm warning was also in effect for the entire Georgia coast and the lower South Carolina coast.
Meanwhile, Gov. Rick Scott postponed a political meeting with presumptive Republican presidential nominee Donald Trump scheduled Monday in New York so he can remain in the state capital to monitor the weather.
Scott warned residents not to simply look at the center of the storm, saying the heaviest rain will be to the east and west of it.
"I want everyone to be safe. I've talked to utilities and sheriff's departments, but residents have to do their part," Scott said.
Colin was expected to pass the Georgia coast before dawn Tuesday, said Dennis Jones, director of the Chatham County Emergency Management Agency.
Jones said flash floods appeared to pose the greatest threat, with the worst flood potential expected late Tuesday.
About 7,600 people were without power in the Tampa Bay area. Duke Energy said Monday afternoon it had 3,600 customers without electricity, while Tampa Electric Company said on its website that 4,022 people were experiencing outages. In Jacksonville on Florida's Atlantic coast, about 2,300 customers were without power as heavy rains hit the area late Monday, according to the Jacksonville Energy Authority.