Irene Wasn't a Hurricane When It Hit N.J., Report Says

Hurricane Irene would have been the first hurricane to make landfall in New Jersey in more than a century, had it actually been packing hurricane-strength winds at the time.

But by the time Irene rolled ashore at Little Egg Inlet in southern Ocean County on Aug. 28, 2011, its wind speed had already decreased to 69 mph — a full 5 mph. short of hurricane strength — meaning it was actually just a tropical storm.

The new findings were released Dec. 14 by the National Hurricane Center, the latest of equivalent post-mortems the agency has posted on every other storm of the 2011 hurricane season. Every year, the hurricane center releases "tropical cyclone reports" on each named storm after hurricane season ends Nov. 30.

The highest gusts of wind unofficially recorded on instruments at 59th Street in Ocean City were in the 50 to 59 mph range, Frank Donato, Ocean City's emergency management coordinator, reported at the time.

The high tide on the evening of Aug. 27, the night before Irene made landfall, was 4.8 feet above average sea level, according to U.S. Geological Survey instruments that were installed at the a few months earlier. A typical high tide is about 3 feet above average sea level, and the Dec. 11, 1992 storm, by comparison, was 7.2 feet above.

The report said a storm surge of 3 to 5 feet along the state's shoreline caused moderate to severe tidal flooding with extensive beach erosion, but the bulk of the damage caused by Irene was in New Jersey's northern counties due to river flooding.

"The most severe impact of Irene in the northeastern United States was catastrophic inland flooding in New Jersey, Massachusetts and Vermont," the report stated.

The report said it was "surprising" that Irene weakened significantly between the Bahamas and North Carolina, never to regenerate on its eventual trek northward toward New Jersey. Hurricane center meteorologists believe that after the storm's inner eyewall eroded near North Carolina, Irene did not act as most storms typically do, and contract at the outer eyewall, allowing for restrengthening.

"Instead, Irene’s structure was characterized by a series of rainbands, resulting in a broad and diffused wind field that slowly decayed," the report said.

According to the hurricane center, reports indicate that Irene was directly responsible for 49 deaths: five in the Dominican Republic, three in Haiti, and 41 in the United States. In the United States, six deaths were attributed to storm surge, waves or rip currents; 15 to wind, including falling trees; and 21 to rainfall-induced floods.

The storm caused $7 billion in property damage, the report said.

A full copy of the report can be downloaded from the National Hurricane Center's website.