A slow-moving depression strengthened into a tropical storm as it slogged toward the Gulf Coast on Friday, packing walloping rains that could drench the region with up to 20 inches.
Tropical Storm Lee, the 12th named storm of the Atlantic hurricane season, was moving northwest at just 2 mph, according to the National Hurricane Center in Miami. The storm's center is expected to approach the Louisiana coast over the weekend.
Tropical storm warnings were issued from Mississippi to Texas, including New Orleans, and flash flood warnings extended along the Alabama coast into the Florida Panhandle. Officials in several coastal Louisiana communities called for voluntary evacuations.
The National Hurricane Center said the system will dump 10 inches to 15 inches of rain over southern areas along the Gulf, and as much as 20 inches in some spots.
Mississippi Gov. Haley Barbour declared a state of emergency in seven counties Friday. He cautioned residents not to underestimate Lee, which he said is expected to cause "tremendous flooding."
Louisiana Gov. Bobby Jindal declared a state of emergency Thursday due to the threat of flash flooding. State climatologist Barry Keim said the system could drench parts of the region with up to 20 inches of rain.
"We could see sustained winds of up to 20 to 30 miles per hour with even higher gusts along a significant portion of the coastal zone. So it's time to batten down the hatches and get ready to deal with this guy."
Louisiana needs rain — just not that much, that fast. Both Texas and Louisiana have been suffering through drought. New Orleans, which was least affected by the drought, already was being pelted by sporadic rain. More of a problem is stubborn marsh fire that has blanketed the city with smoke, though the rain will help extinguish it.
"Sometimes you get what you ask for," said New Orleans Mayor Mitch Landrieu, who also declared a state of emergency on Friday. "Unfortunately it looks like we're going to get more than we needed."
The Army Corps of Engineers, which operates major flood control structures at New Orleans, was monitoring developments but didn't plan on closing any flood control structures yet, spokesman Ricky Boyett said in an email.
The storm's biggest impact so far has been in the Gulf of Mexico oil fields. About half the Gulf's normal daily oil production has been cut as rigs were evacuated.
Federal authorities said 169 of the 617 staffed production platforms had been evacuated, along with 16 of the 62 drilling rigs. That's reduced daily production by about 666,000 barrels of oil and 1.7 billion cubic feet of gas.
Forecasts were for landfall over the weekend on southern Louisiana's coast. Lee's center was about 185 miles southeast of Cameron, La., and the storm had maximum sustained winds of 40 mph Friday afternoon.
"This could be a very heavy, prolific rainmaker," National Weather Service meteorologist Frank Revitte said.
As hurricane season hits its peak in the Atlantic, storm watchers also were monitoring other disturbances.
Katia was spinning in open waters, having regained hurricane strength Friday after weakening the day before. Forecasters said it would continue to grow stronger.
The hurricane was about 705 miles east of the northern Leeward Islands and moving west-northwest near 15 mph with maximum sustained winds early Friday of about 75 mph. The hurricane center said it was too early to tell if Katia will hit the U.S. but that it is expected to pass north of the Caribbean.
There was also a slow-moving low pressure system about 450 miles south of Halifax, Nova Scotia, that had a 60 percent chance Friday of becoming a tropical cyclone in the next two days.
They all come on the heels of Hurricane Irene, which brought destruction from North Carolina to New England late last month.
Tegan Wendland in Baton Rouge, La., contributed to this report, which contains material from The Associated Press.