Well, that was quick.
Issac has been on a strength rollercoaster the last day or so, weakening to a tropical depression before restrengthening to a tropical storm Friday before fizzling out to a remnant low Saturday morning.
"A NOAA Hurricane Hunter aircraft investigated Isaac over the past few hours and was unable to identify a well-defined center," said the final discussion on the system from the National Hurricane Center issued at 4 a.m. CDT Saturday. "Since Isaac does not have a well-defined center, it no longer meets the NHC definition of a tropical cyclone and this is the last advisory."
The discussion added that models do not suggest any significant redevelopment of Issac as what's left of the system moves westward across the Caribbean, though gusty winds and occasional downpours are possible for parts of Hispaniola and Jamaica.