As predicted by all of the major players at the start of this year's Atlantic hurricane season, 2010 proved to be a very active year. The factors which came together to make this year about twice as active as the average year included a moderate La Nina event in the eastern Pacific resulting in lower than normal wind shear over the Atlantic, and very warm sea surface temperatures in the Atlantic and Caribbean.
Fortunately, there also was also persistent high pressure along the Gulf Coast, the Bermuda High was displaced eastward from it's normal position, and more strong troughs of low pressure over the U.S. East Coast than usual. These factors combined to produce an "offense that couldn't score from the Red Zone" as Accuweather's Joe Bastardi metaphorically stated -- an abnormally high number of storms with an almost unprecedented lack of U.S. landfalls.
At the end of the season, a total of 19 storms were named, 12 of which became hurricanes, and 5 of which reached major (category 3+) status, compared to the long-term averages of 9 storms, 3 hurricanes, and 2 majors. The chart below shows how some of the more well-known forecasters did with their early-season projections:
| NOAA/NWS | 14-23 | 8-14 | 3-7 |
| Klotzbach/Gray (CSU – 6/2/10) | 18 | 10 | 5 |
| Joe Bastardi (AccuWeather) | 16-18 | 10-11 | 5 |
| Actual | 19 | 12 | 5 |
| Long-term Average | 11 | 6 | 2 |
Some of the highlights of the 2010 season:
- The 19 named storms was the 3rd highest total in recorded history (behind 2005 and 1933).
- The 12 hurricanes tied 2010 with 1969 as the 2nd highest hurricane count (first: 2005 with 15).
- Despite a season that was roughly twice as active as the average year, only one weak Tropical Storm (Bonnie) made a direct U.S. landfall, hitting south FL in August with 40 mph wind. Hermine narrowly missed direct landfall, striking extreme northeastern Mexico, but brought flooding to the Rio Grande basin of southern TX. Hurricane Earl also grazed the eastern seaboard. Typically, about 1/3 of all named storms reach a U.S. coastline.
- Until 2010, there have been no seasons with 10+ hurricanes in which none struck the U.S.
- There have been 18 consecutive hurricanes, dating back to 2008, which have missed the U.S.
- No major hurricanes (category 3+) have hit the U.S. since Wilma in 2005 (Katrina was also a 2005 storm). This 5-year drought has not happened since 1915 and there is no precedent for a 6-year period without a U.S. land-falling major hurricane (uh-oh?).
- There were 3 hurricanes occurring simultaneously on September 16 (Karl, Igor, Julia), which has occurred only 8 other times in recorded history (see the satellite image of these storms above). On the previous day (September 15), Igor and Julia were simultaneously at category 4 strength, only the 2nd time this has been known to occur.
- A total of four category 4+ storms occurred in 2010 (tied for 3rd for most cat 4+ storms in a year) and all four occurred within a 20-day span -- also a record.
We extend our thanks to Jeff Masters at Weather Underground and his sources, as well as NOAA, for originally publishing many of these stats.
If you'd like to take a look at MWN Blog posts from earlier this year that referenced the "upcoming" season and for comparison, check these out:
You may also be interested in a NOAA story on the 2010 season, a "gentle giant" as it is referred to. You can find it here. It will be interesting to see what 2011 has in store and whether or not the streak of non-land-falling storms continues!
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