Tallahassee, Fla. (AP) -- Tropical Storm Colin formed in the Gulf of Mexico on Sunday and was speeding on a course to hit Florida on Monday with rains that forecasters said could cause serious flooding along much of the state's Gulf coast.
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 quickly 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.
It is the latest in a series of severe weather events across the country, from record-breaking heat in the West, flooding in Texas and storms that are expected to cause problems in the nation's capital and mid-Atlantic region.
The storm was moving at a speed of about 12 mph (19 kph) and was about 450 miles southwest of Tampa on Sunday night.
"It's going to impact most of the state in some way," Gov. Rick Scott said in a phone interview. "Hopefully we won't have any significant issues here, but we can have some storm surge, some rain, tornados and some flooding."
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.
Tropical storms carry wind speeds of between 39 mph (63 kph) and 73 mph (117 kph).
Tropical Storm Colin was likely to bring dangerous rainfall levels, and residents were warned about possible flooding and hazardous driving conditions. Rain began falling in the Tampa Bay area just past noon Sunday.
Colin is expected to produce rainfall amounts of 3 to 5 inches with up to 8 inches possible in western Florida, eastern Georgia, and coastal areas of the Carolinas through Tuesday, forecasters said Sunday.
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.
The National Weather Service in Mobile issued a flood warning for the Shoal River near Crestview and warned of possible widespread flooding in streams, creeks, and canals. Wind gusts threatened to bring down trees and branches and cause power outages.
The Georgia coast and the north Florida Atlantic coast were placed under a tropical storm watch Sunday evening.
Sand bags were being distributed to residents in St. Petersburg, Tampa and nearby cities.
"We're surrounded on three sides by water," said Pinellas County spokesman Nick Zoller, who said the county distributed 3,300 sand bags on Saturday, a number he expected to go up now that a tropical storm warning is in effect.
Just to the north, Pasco County Emergency Services Director Kevin Guthrie said the message is to be prepared.
"We are going to flood in parts of Pasco County," Guthrie said in an email.
Fort Hood officials have identified the last of nine soldiers who died in Texas floodwaters during a training exercise as a 25-year-old Army specialist from California.
Army officials on Sunday said Spc. Yingming Sun enlisted in 2013 and first arrived at Fort Hood nearly two years ago. He and eight others who were previously identified died when fast-moving waters washed a 2 ½-ton vehicle from a low-water crossing Thursday.
Three others soldiers survived and have returned to duty.
Heavy and persistent storms the past two weeks have dumped more than a foot of rain in parts of Texas. The rain is expected to diminish this week and dry out areas such as Southeast Texas, where officials gave evacuation order to about 2,000 homes.
TAKING AIM AT THE NATION'S CAPITAL
The National Weather Service is warning of an "enhanced" risk of severe storms in the mid-Atlantic region with the possibility of damaging winds.
Sterling, Virginia-based meteorologist Chris Strong says the primary threat in the Baltimore-Washington metropolitan area is from damaging wind gusts, and there's a lesser threat for tornados.
Wakefield, Virginia-based meteorologist Lyle Alexander says the threat on the Eastern Shore is from winds and more localized heavy rain.
The weather service warns that heavy rain in central Virginia and the Shenandoah Valley could mean flooding in areas that received rain Saturday. Flash flood watches are in effect until evening.
Mount Holly, New Jersey-based meteorologist Lance Franck says in Delaware the threat is from high winds and torrential downpours bringing flooding to urban areas and areas with poor drainage.
In New York City, the last day of a music festival that was to include performances by Kanye West and Death Cab for Cutie was canceled because of weather concerns.
The National Weather Service said Phoenix hit 113 degrees on Sunday, marking the third day in a row setting record high temperatures in Arizona's Urban Heart.
Much of Southern Arizona, from Phoenix to Nogales, is under an excessive heat warning.
Other western and southwestern U.S. states are experiencing above-normal temperatures in the triple-digits.
Officials are warning residents to stay hydrated and avoid the outdoors between 10 a.m. and 4 p.m., when temperatures are highest.
The National Weather Service said a tornado touched down in eastern Indiana when a weekend storm passed over the area.
The weather service's Wilmington, Ohio, office said Sunday that a tornado with wind speeds of up to 85 mph cut a 1¼ mile path Saturday near Richmond, Indiana. No one was injured by the EF0 tornado, which is the weakest tornado designation the weather service assigns.