( CNN ) -- Its winds no longer a major threat , a stalled Tropical Storm Karen still carried the threat of storm surge to portions of the U.S. Gulf Coast . The National Hurricane Center ( NHC ) said the storm 's maximum sustained winds were at 40 mph on Saturday evening . The storm was idle much of Saturday night , but forecasters predicted it would turn northeast and gain speed going into Sunday , when it was expected to weaken to a tropical depression . The center of the storm will move just south of the Gulf Coast from Alabama to the Florida Panhandle on Sunday night and Monday , the NHC predicted . The storm will dissipate into a remnant area of low pressure on Sunday evening , with no secondary landfall along the northern Gulf Coast , forecasters said . A tropical storm warning was in effect for Grand Isle , Louisiana , to the mouth of the Pearl River . Coastal residents were warned that storm surges and dangerous waves remained possible . The storm is expected to drop up to 3 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 . Storm surges also are a concern . If peak surges coincide with high tide , water could reach up to 3 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 . CNN 's Sean Morris , Eliott C. McLaughlin , Todd Borek and David Simpson contributed to this report .
Tropical Storm Karen has sustained winds of 100 mph . Storm is stationary south of Louisiana . Is expected to weaken to a tropical depression . Coastal residents warned of storm surges and dangerous waves .