- Despite being very active and causing 120 deaths and $11 billion in damages, 2011 was mostly a year of misses for Pacific and Atlantic hurricanes. The Atlantic hurricane season ends on Nov. 30. (NOAA/EVL)
Swingandamiss. That's the 2011 hurricane season in a nutshell, although there were a couple notable exceptions.
The Atlantic portion of the season, which ends after Nov. 30, fit solidly within NOAA's forecast with an amazing 19 tropical storms and a near-average seven hurricanes and three major hurricanes. That's a whirlwind of oceanic activity: 2011 was the third-most active year for tropical storms on record, tying with 1887, 1995 and 2010. Yet most veered away from the United States before any harm could be done. You can see how they scattered over the hemisphere like startled elephants in the above composite map from NOAA, where the maximum intensities of the storms are color-coded. (Large version.) The map was built on data from the meme-rific HURDAT tracking set.
The Americas did not emerge unscathed from these monster storms. Flooding, wind and associated hurricane carnage caused a known 120 fatalities. Tropical Storm Arlene killed about two-dozen people when it mowed over Mexico in late June. The costs of Hurricane Irene are still being calculated, with the latest estimates hovering around $10 billion and human costs of 55 lives. Tropical Storm Lee caused about $1 billion in damages and spawned a bunch of tornadoes in the South, to boot. However, there's some good news in that the U.S. escaped a brush with a major hurricane for the sixth consecutive year since Hurricane Wilma hit in 2005. That's a record stretch of relative safety.
Why was the season so feisty? Part of the blame lies with La Niña, the recurring climate pattern that puts dampers on Pacific storms while injecting the Atlantic with the weather equivalent of trailer meth. There's also a not-quite-understood trend in the climate that's been churning out active hurricane seasons since 1995.
Surprisingly, none of the first eight tropical storms reached hurricane status, a record since reliable reports started in 1851. Hurricane Irene's effects in the Caribbean and the United States lead to 55 deaths and accounted for the bulk of this season's damage, more than $10 billion. Irene was the first landfalling hurricane in New Jersey in 108 years. Hurricane Katia had far-reaching effects causing severe weather in Northern Ireland and Scotland and power blackouts as far east as Saint Petersburg in Russia. Tropical Storm Lee caused major flooding in Pennsylvania, New York and into the Canadian provinces of Quebec and Ontario. The strongest storm of the season was Ophelia, which reached category four strength in the Atlantic Ocean east of Bermuda.
You can see every 2011 tropical tempest form and move across the globe in the below time-lapse video. The animation is actually a series of shots taken by the GOES-13 satellite every 30 minutes from June 1 to Nov. 28. For the storm tracks of past seasons, the National Hurricane Center's got you covered all the way back to 1851.