People living or sheltering far from the Texas-Louisiana Gulf Coast might not have escaped Rita's wrath yet. Weather forecasters say they expect the storm to stall over the region for several days with torrential rains.
The National Hurricane Center warned that accumulations of 25 inches are possible across eastern Texas and western Louisiana.
"This could be half a year's worth of rain in a couple of days," said Rick Smith, a National Weather Service meteorologist in Fort Worth. "It's something we're going to be watching very closely."
Forecasters warned residents yesterday to expect "major river flooding" in eastern Texas and western Louisiana. Flash flooding and high water could hit places as far north as southeastern Oklahoma and southwestern Arkansas.
"It could even require evacuations of residents," Smith said.
The dangers to life and property from high winds and coastal storm surges get most of the attention when a hurricane makes landfall. But in recent years, with more timely warnings and coastal evacuations, inland flooding has caused most storm deaths.
"Freshwater flooding has caused 59 percent of the U.S. tropical cyclone deaths in the past 30 years," Smith said.
After making landfall overnight, Hurricane Rita was expected to slow to a crawl, become nearly stationary by tomorrow over northern Louisiana, then linger until Tuesday.
All this week, a high-pressure system over the southern United States prevented the storm from turning north toward Florida, Alabama or Mississippi. It kept Rita steaming westward toward the Texas Gulf Coast, said meteorologist Mark McInerney, of the National Hurricane Center in Miami.
The high-pressure barrier has moved east, which might have been expected to kick Rita's remains northward into the center of the country.
But the high pressure has been replaced by high-altitude steering winds, a jet stream blowing south from Lake Superior into Texas. And that will block Rita from moving quickly inland, away from the hard-hit Gulf Coast.
"It's not just going to go away after it makes landfall," Smith said. "It's going to be a continuing problem for several days in our area."
Most imperiled by the rain, Smith said, will be the low, rolling, piney-woods region within 100 miles of the Texas-Louisiana line.
The region has been dry, he said, and a prolonged rain might have been welcomed, but "unfortunately, in some cases it's going to fall in such a short period of time that it will overwhelm the drainage systems and cause serious flooding."
Although the region is not densely settled, Smith said, "there are populations at risk with this event." Shreveport, La.; Nacogdoches, Longview and Lufkin, Texas; the two Texarkanas, in Arkansas and Texas; and many small towns could be affected.
Flooding along the Red River in Shreveport and Alexandria, La., is also a possibility, said Texas State climatologist John Nielsen-Gammon, a meteorology professor at Texas A&M University in College Station. The Sabine (pronounced suh-BEEN) River, which forms the southern Texas-Louisiana border, might also flood.
"I would expect some places would see what we call a 100-year flood," Nielsen-Gammon said. "That means people should prepare for the water being higher than they've ever seen it."
Rita might run into the Ouachita Mountains in western Arkansas and eastern Oklahoma, where rising terrain would cool the storm's humid air and wring out even more of its moisture as rain.
"That means flash flooding in those mountains and the southern foothills is very likely if the storm stalls nearby," Nielsen-Gammon said.
Persistent heavy rains will also affect the coastal cities in Rita's path.
In Houston, that is likely to recall Tropical Storm Allison, which came ashore in June 2001 and stalled, dropping 37 inches of rain on the city in five days and causing 22 fatalities in the region - including a woman who drowned in a parking garage elevator - and $4.88 billion in damage.
It was the costliest natural disaster in Houston's history and the costliest tropical storm in U.S. history, according to the National Weather Service.
In some Houston residential areas, "the water was getting up close to the eaves, similar to the amount of water in some neighborhoods of New Orleans," Nielsen-Gammon said.
"Normally, the water drains off into creeks and bayous," he said. "At times during the Allison flood there was no such thing. The water was continuous across the whole area. The term watershed no longer had a meaning."