The US hurricane season has come and gone, with the predicted record windstorms failing to materialise. Of 19 named storms, only Hurricane Irene made landfall in the US.

Nevertheless, the 19 storms made the 2011 hurricane season the third busiest (along with 2010, 1995 and 1887) since records started in 1851. Catastrophe modeller RMS estimates insured losses of $US5 billion (4.8 billion) from this season’s events.

The season, which stretches from June 1 to November 30, got off to the slowest start on record with none of the first storms reaching hurricane status.

Nevertheless, in early August weather experts were still predicting a 70% chance of a major hurricane making landfall amid above average activity.

Later that month Hurricane Irene, which battered the US east coast and caused major flooding, became the first hurricane to hit since Ike in 2008 and the most significant tropical storm to hit the northeast since Bob in 1991.

“Irene broke the ‘hurricane amnesia’ that can develop when so much time lapses between landfalling storms,” National Oceanic Administration director Jack Hayes said.

“This season is a reminder that storms can hit any part of our coast and that all regions need to be prepared each and every season,” he said.

Hurricane Irene hit the US coast in North Carolina after causing $3 billion ($2.9 billion) damage in the Caribbean, and despite its reduced strength estimates of the insurance losses it caused as it ran up the coast to New Jersey and New York are as high as $US3.4 billion ($3.3 billion).

Two other tropical storms – Don and Lee – made landfall but neither was very powerful.

In a report on the season, Colorado State University meteorologists William Grey and Phil Klotzbach say the above-average cyclone activity they forecast had occurred, but “not at the levels we predicted”.

“It is impossible to predict months in advance the mid-latitude flow patterns that dictate US and Caribbean hurricane landfall,” they wrote in their summary of the 2011 hurricane season. “We only make predictions of the probability of landfall.

“The primary reason why we believe the US has been so fortunate is due to mid-level steering currents that have in recent years tended to steer storms away from the US.”