June 1st is the official first day of the Atlantic Ocean hurricane season. What is the expectation for tropical storms in the Atlantic in 2011? The Climate Prediction Center and the hurricane group at CSU have issued seasonal forecasts that I’ll discuss.
This outlook reflects an expected set of conditions that is conducive to above-normal Atlantic hurricane activity. These conditions are based on three climate factors:
- The tropical multi-decadal signal, which has contributed to the high-activity era in the Atlantic basin that began in 1995,
- A continuation of above-average sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea (called the Main Development Region),
- ENSO-neutral conditions most likely (no El Niño or La Niña), with lingering La Niña impacts into the summer.
The conditions expected this year have historically produced some active Atlantic hurricane seasons. Therefore, the 2011 season could see activity comparable to a number of active seasons since 1995. We estimate a 70% probability for each of the following ranges of activity during 2011:
- 12-18 Named Storms,
- 6-10 Hurricanes,
- 3-6 Major Hurricanes
- 16 Named Storms,
- 9 Hurricanes,
- 5 Major Hurricanes
The CSU group has plenty of other detailed information regarding potential for landfalling hurricanes along different portions of the U.S. coast (e.g., FL, NC, TX, etc.)
In summary, another above-average season is being projected by the experts. The long-term average for these phenomena are as follows: 11 named storms, 6 hurricanes, and 2 major hurricanes.
There were 19 named storms, 12 hurricanes, and 5 major hurricanes in 2010:
Image courtesy of Unisys.
On a related note, MSNBC ran a story this morning discussing the top-5 cities that are overdue for a direct hit by a hurricane. They are:
- Honolulu, HI
- San Diego, CA
- New York City, NY
- Savannah, GA
- Tampa Bay, FL
Finally, I wanted to point out that an area of disturbed weather currently exists 200 miles east of Jacksonville, FL. Designated 93-L by the Tropical Prediction Center, it is moving WSW at 20mph. It will move over Florida this afternoon. The TPC has given the disturbance a 30% chance of organizing into a Tropical Depression in the next 48 hours. See Jeff Master’s write-up for more information.