NOAA’s 2010 Atlantic Hurricane Season Outlook calls for an 85% chance of an above normal season. The outlook indicates only a 10% chance of a near-normal season and a 5% chance of a below-normal season. See NOAA definitions of above-, near-, and below-normal seasons. The Atlantic hurricane region includes the North Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico.
This outlook reflects an expected set of conditions that is very conducive to increased Atlantic hurricane activity. This expectation is based on the prediction of three climate factors, all of which are conducive historically to increased tropical cyclone activity. These climate factors are: 1) the tropical multi-decadal signal, which has contributed to the high-activity era in the Atlantic basin that began in 1995, 2) exceptionally warm sea surface temperatures in the tropical Atlantic Ocean and Caribbean Sea (called the Main Development Region), and 3) either ENSO-neutral or La Niña conditions in the tropical Pacific, with La Niña becoming increasingly likely. In addition, dynamical models forecasts of the number and strength of tropical cyclones also predict a very active season.
The conditions expected this year have historically produced some very active Atlantic hurricane seasons. The 2010 hurricane season could see activity comparable to a number of extremely active seasons since 1995. If the 2010 activity reaches the upper end of our predicted ranges, it will be one of the most active seasons on record.
We estimate a 70% probability for each of the following ranges of activity this season:
- 14-23 Named Storms,
- 8-14 Hurricanes
- 3-7 Major Hurricanes
- An ACE range of 155%-270% of the median.
The seasonal activity is expected to fall within these ranges in 7 out of 10 seasons with similar climate conditions and uncertainties to those expected this year. They do not represent the total possible ranges of activity seen in past similar years.
It only takes one storm hitting your area to cause a disaster, regardless of the activity predicted in the seasonal outlook. Therefore, residents, businesses, and government agencies of coastal and near-coastal regions are urged to prepare every hurricane season regardless of this, or any other, seasonal outlook.
While NOAA does not make an official seasonal hurricane landfall outlook, the historical probability for multiple U.S. hurricane strikes, and for multiple hurricane strikes in the region around the Caribbean Sea, increases sharply for exceptionally active (i.e. hyperactive) seasons (ACE > 175% of median). However, predicting where and when hurricanes will strike is related to daily weather patterns, which are not predictable weeks or months in advance. Therefore, it is currently not possible to reliably predict the number or intensity of landfalling hurricanes at these extended ranges, or whether a given locality will be impacted by a hurricane this season.