Taking a look back at an entire hurricane season, which lasts from June 1 through November 30, might seem like a daunting task, but thanks to NOAA's quickly moving and all-encompassing continuous loop of satellite images, you can do it less than 5 minutes!
The Atlantic basin season was very active, with 19 storms (18 named during the season and one unnamed storm that was identified as a tropical storm in the post-season analysis), including 7 hurricanes. The average number of storms in an Atlantic basin season from 1966 through 2009 is 11, including 6.2 hurricanes.
Hurricane Irene, which appears for roughly 20 seconds roughly 2 into the video, caused billions of dollars in damage. According to NOAA, ended the country's amnesia related to the danger of hurricanes. While that point is debatable (Did Hurricane Irene End U.S. Hurricane Complacency?), it is the most obvious and dramatic feature in the video.
With a video that encompasses such a prolonged period during a very active season, a number observations came to mind as I watched the video, but I'm sure there are many others.
- A few of the storms were of the type that may have gone unnoticed before the days of satellite observation given their lack of proximity to land. These include tropical storms Bret, Franklin, Gert, and Philippe.
- The peak of the season is August and September, and it's at this time that the long-tracking hurricanes are likely, and many of these start from African waves and take a long trip across the Atlantic. Hurricanes Irene, Katia, and Maria are three examples of that this season.
- Two of the main factors that disrupt or inhibit the formation of tropical storms and hurricanes are dry air and vertical wind shear (an increase in wind with height that interferes with tropical formation). It's interesting to watch storms wax and wane as they battle these atmospheric factors, such as was the case with tropical storms Don and Emily, as well as with one hurricane, Ophelia.
- During the early and latter parts of the season, when tropical formation occurs, it often does so closer to land or as an extra-tropical (non-tropical) system changes forms and becomes tropical in nature. The first storm of the year, Tropical Storm Arlene, formed close to land in the Bay of Campeche, and Tropical Storm Sean, near the end of the video, formed from what had been a non-tropical low pressure system
The video, embedded above, is available on YouTube (The 2011 Hurricane Season in 4.5 Minutes)