Federal weather forecasts for Hurricane Sandy were exceptionally accurate last fall, but the warnings themselves were confusing, an internal review has found.

The gigantic October storm lost tropical characteristics hours before landfall in New Jersey, so the National Oceanic and Atmospheric Administration stopped calling it a hurricane. Instead it shifted its focus to flooding and high-wind warnings, and moved responsibility from the National Hurricane Center in Miami to local weather offices.

NOAA's self-assessment said that move led to confusion among the public and the news media, a complaint made by independent meteorologists.

The 66-page report uses confusion 88 times.

The confusion stemmed from a "lack of flexibility" about what Sandy was when it morphed from a hurricane into a post-tropical storm. Such a storm is essentially a hurricane that no longer gets its energy from warm water and loses its eye. Coastal residents and the news media thus misinterpreted Sandy's potential effects, the report said.

The report recommended that hurricane warnings should continue even when a storm is downgraded and should come from the hurricane center. That's a change NOAA adopted last month.

The way around all this is to emphasize what a storm does more than what to call it, said report author Peyton Robertson, who directs NOAA's Chesapeake Bay office.

"Just saying a hurricane is coming doesn't tell people what they're supposed to do," Robertson said.

The report says the biggest problem was warning of the massive storm surge. Nearly four out of five coastal residents surveyed said Sandy's surge was higher than they expected.

Robertson said people did not understand terms like mean high water or that coastal flooding can go far inland.

Even so, Robertson said, surveys did show that people knew how serious Sandy was.

The report highlighted a Philadelphia weather service office where a meteorologist sent out "a personal plea" for people to take the storm seriously that included, "if you think the storm is overhyped and exaggerated, please err on the side of caution. You can call me up on Friday (contact information is at the end of this briefing) and yell at me all you want."