Today marks the end of the 2011 Atlantic hurricane season, which officially runs from June 1 through Nov. 30. To honor the occasion, NOAA has produced the following video, which condenses the entire six-month season into a four-minute flurry:



The first system, Tropical Storm Arlene, doesn't appear until 0:45, but things pick up after that. In fact, even though only one hurricane (Irene) made landfall in the U.S. this year, it was still an above-average season, with a total of 19 tropical storms forming across the Atlantic Basin. That's the third-highest total since record keeping began in 1851, and well above the yearly average of 11 tropical storms.


There were also seven hurricanes and three major hurricanes in 2011, just slightly above the annual average of six and two, respectively. Irene was the only one that hit the U.S., and it was the first to do so since 2008, when Ike slammed into southeast Texas.


Since Irene was also "the most significant tropical cyclone" in the Northeast since 1991's Hurricane Bob, according to NOAA, it helped remind many Americans of how dangerous such storms can be. Irene killed 55 people in the U.S. and the Caribbean, and caused an estimated $10 billion in damage.


"Irene broke the 'hurricane amnesia' that can develop when so much time lapses between landfalling storms," National Weather Service Director Jack Hayes said in a statement this week. "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."


But while the 2011 season featured more storms than usual, most of them either stayed away from land or weakened before wreaking much havoc. As NOAA notes, 2011 marks a record six straight years without a major hurricane (Category 3, 4 or 5) hitting the U.S. The last one was Hurricane Wilma in 2005.


Still, hurricane categories only indicate wind speed, and wind isn't a cyclone's only weapon. Arlene, for example, brought heavy rain, floods and mudslides to Mexico and Central America in late June, killing at least 22 people and causing $200 million in damage. Irene and Lee also dumped huge amounts of rain on the U.S. and Canada, spurring disastrous floods from Louisiana to Quebec. On average, more than half of all deaths from tropical storms are due to flooding, NOAA points out.


Aside from tropical weather, the video also shows some other interesting events in the atmosphere this year. You can see thunderstorms flare up across the central and eastern U.S., for example, or watch as rain clouds continually sidestep Texas, allowing the state's historic drought to keep festering.


The next hurricane season will kick off on June 1, 2012, and NOAA plans to issue its initial forecast in May. 


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