As thunderstorms began rocking the Tennessee Valley about 6 p.m. Sunday, a meteorologist saw a jagged red splotch dominating the Chattanooga radar.

"The main story's the rain," said David Gaffin, a meteorologist at the National Weather Service in Morristown, Tenn. "It's going to stay over us for a long time and accumulate enough to cause some flooding problems."

Forecasts indicate that storms will linger into the morning before gradually leaving the area by this afternoon. NewsChannel 9 meteorologist Allison Chinchar said she expects 2 to 3 inches of rain into this morning, but some areas could see 6.

It wasn't clear which areas would be wettest.

"A lot of stuff is firing up in Mississippi and Alabama, but a lot of it hasn't formed yet," she said. "Two miles away there could be regular showers, and in your neighborhood you could have 5 inches."

Several experts were concerned that the South Chickamauga Creek could overflow, a thought that had Mr. Gaffin a little worried about this morning.

"That creek is expected to get up to 18 and a half feet, which is barely above its flood stage of 18 feet," Mr. Gaffin said. "The good thing is, I don't think it'll be as bad as what happened over in Middle and West Tennessee."

State flooded

A devastating and deadly line of thunderstorms rocked Tennessee and northern Mississippi over the weekend, killing at least 15 people, closing scores of highways, and leaving weeks of cleanup for thousands of residents whose homes were damaged.

Thousands of residents were evacuated and hundreds of others were rescued from their homes - some plucked from rooftops - as floodwaters from swollen rivers and creeks inundated neighborhoods across the region. Hospitals, schools and state buildings also were flooded.

Tennessee officials said Sunday the flooding is the worst since the mid-1970s. Tornadoes or high winds killed at least four people, unexpected flash floods swept some unsuspecting residents to their deaths and an untold number of homes were flooded as urban drainage systems and watersheds struggled to remove the deluge.

Tennessee Gov. Phil Bredesen called it an "unprecedented rain event," but that failed to capture the magnitude. More than 13 inches of rain fell in Nashville over a two-day period, nearly doubling the previous record of 6.68 inches that fell in the wake of Hurricane Fredrick in 1979.

Flooding and damage were so widespread in Tennessee that Gov. Bredesen asked the state's Army National Guard to help and dozens of vehicles and personnel were put to work rescuing stranded residents. Nashville Mayor Karl Dean reported more than 600 water rescues in the city alone.

At least 11 people died in Tennessee.

The state had multiple interstates closed over the weekend including sections of I-40 and I-24. Gov. Bredesen said in Middle Tennessee alone more than 150 roads were closed.

Mr. Gaffin said forecasters anticipated a quicker arrival of severe weather Sunday in Chattanooga, but the interplay between the storm's front and the jet stream facilitated a more gradual pace.

Ms. Chinchar said that was why the rain could be a factor until at least this morning.

"It literally almost got to Nashville and stopped for six hours," Ms. Chinchar said. "But we don't anticipate that kind of stalling. It's one thunderstorm after another after another."

She recommended several safeguards.

"If you start to see puddles in your basement, bring anything that can go bad up to higher ground," she said. "Take everything upstairs, use those Rubbermaid containers. Those won't go bad."

Mr. Gaffin said temperatures will stay in the upper 80s, about 10 degrees above normal.

* Confirmed weather-related deaths in Tennessee this weekend: 11

* 2009 yearly rainfall up to April 30: 16.53 (4.14 below normal)

* 2010 yearly rainfall up to April 30, 2010: 15.75 inches (4.92 below normal)

* Expected rainfall in Tennessee Valley by end of today: 2-6 inches

Source: AP and National Weather Service