NEW: Hurricane watch canceled; tropical storm watch continues Barrier island town of Grand Isle, Louisiana, gets evacuation order Coastal residents warned of storm surges and dangerous waves (CNN) -- Tropical Storm Karen apparently will not become a hurricane, but the storm still means a soggy weekend for parts of the U.S. Gulf Coast. The storm, expected to near land between southeastern Louisiana and the Florida Panhandle on Saturday night or Sunday morning, weakened Friday morning as it churned in the central Gulf of Mexico, the National Hurricane Center said. The hurricane center canceled a hurricane watch Friday afternoon. A tropical storm watch continued from Morgan City, Louisiana, to Indian Pass, Florida. Coastal residents were warned that storm surges and dangerous waves remain possible. Karen's maximum sustained winds dropped to about 50 mph by midday Friday, down from 60 mph earlier in the day. The storm was centered about 235 miles south-southwest of the Mississippi River's mouth about 4 p.m. CT (5 p.m. The mayor of Grand Isle, Louisiana, on Friday ordered a mandatory evacuation for the barrier island town, CNN affiliate WGNO-TV reported. Grand Isle has about 1,300 residents plus tourists. Mayor David Camardelle ordered them to take camper trailers and recreational vehicles off the island. A tropical storm warning is in effect from Morgan City, Louisiana, to the mouth of the Pearl River on the Louisiana-Mississippi line. 3 to 6 inches of rain The storm is expected to drop 3 to 6 inches of rain over parts of the central and eastern Gulf Coast through Sunday night, mainly near and to the east of the storm's center, the hurricane center said. Isolated storm total amounts of 10 inches are possible. Storm surges also are a concern. If peak surges coincide with high tide, water could reach 3 to 5 feet above ground from the mouth of the Mississippi River in Louisiana to Alabama's Mobile Bay, the center said. "The combination of storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters," the center said. The hurricane center's tracking map shows that the storm could make two landfalls: once over the Louisiana barrier islands Saturday night and again over the Florida Panhandle on Sunday morning. The storm prompted the Federal Emergency Management Agency to recall some of its workers furloughed during the government shutdown. Louisiana Gov. Bobby Jindal and Alabama Gov. Robert Bentley declared statewide states of emergency. A Louisiana law prohibiting price gouging during emergencies went into effect, CNN affiliate WDSU-TV reported. The city is included in the tropical storm watch area. The storm was moving north-northwest at 10 mph Friday morning, the hurricane center said. It is expected to turn north by early Saturday and then northeast on Sunday, the center said. CNN's Sean Morris, Eliott C. McLaughlin and David Simpson contributed to this report.