(Updates with details on damages in Pensacola, Florida)
By Bill Cotterell
TALLAHASSEE, Fla., April 30 (Reuters) - Severe floods in Florida's Panhandle and coastal Alabama deluged roads and engulfed homes and cars on Wednesday, the latest mayhem created by a tornado-packing storm system that has killed at least 34 people in the United States this week.
Florida Governor Rick Scott declared a state of emergency for 26 counties inundated by as much as 1 to 3 inches (2.5 to 7.6 centimeters) of hourly rain as severe thunderstorms raced across the northern part of the state.
Emergency workers received about 300 calls for evacuations in the Panhandle, where up to 22 inches (56 centimeters) of rainfall was recorded in recent days, Scott told reporters at an emergency operations center south of Tallahassee.
"There's a lot of water on the ground," the governor said, adding that the threat for more flash flooding remains.
The flooding appears to be the worst in 30 years in the Panhandle, according to initial radar images of the rainfall, said Eric Esbensen, a National Weather Service meteorologist.
Schools and roads were closed in several Panhandle counties including Escambia, where emergency officials used boats and high-water vehicles to rescue stranded motorists and residents.
State and county officials urged residents not to drive in the treacherous conditions of rising water, damaged roads and storm debris.
Ashton Hayward, the mayor of Pensacola, Florida, said some downtown areas of the Gulf Coast city, were up to four feet under water. On one block, all of the businesses were flooded, he said.
A portion of the Scenic Highway in Pensacola, which runs along a bluff 80 to 100-feet above sea level, collapsed in two places, dropping a car and a truck about 40 feet, Hayward said. No injuries were reported.
An elderly woman died late Tuesday in Escambia County after high waters submerged her car on a highway, the Florida Highway Patrol said.
Along Alabama's Gulf Coast, major county roads were flooded and several rivers overflowed after some areas got between 22 and 26 inches (56 and 66 centimeters) of rain in 24 hours, according to Mitchell Sims, emergency management director for Baldwin County.
"We were rescuing people out of cars, out of ditches, out of homes," Sims said. "We are still getting reports of people trapped."
The storms were expected to spread across portions of the East Coast and could drop 2 to 5 additional inches (5 to 13 centimeters) of rain in some areas and launch fresh tornadoes, said National Weather Service meteorologist Corey Mead.
A flood warning was in effect until Wednesday afternoon for the Washington D.C. metro area, as well as urban areas and small streams between Virginia and Baltimore, Maryland.
Severe conditions may persist into Thursday, though "it looks like the weather may be quieting down as warmer, more humid air is pushed offshore by a cold front moving through the Appalachians," Mead said.
There have been 27 confirmed weather-related deaths and more than 200 people reported injured across Arkansas and Mississippi, the hardest hit of six states struck by the storm system, as tornadoes reduced homes to rubble, shredded trees and launched vehicles into the air.
Deaths have also been reported in Oklahoma, Iowa, Alabama and Tennessee.
President Barack Obama has declared a major disaster in Arkansas and ordered federal aid to supplement state and local recovery efforts, the White House said.
Shelters have been set up for thousands of families forced out of their homes while the National Guard, local police and residents who lost all their possessions sifted through the rubble looking for more victims.
More than 2,000 houses and 100 commercial properties have been reported damaged. (Additional reporting by Barbara Liston in Orlando, Curtis Skinner in New York, Verna Gates in Birmingham, Kevin Gray in Miami; Writing by Eric M. Johnson and Colleen Jenkins; Editing by Gunna Dickson)