Today, Phil Klotzbach and Bill Gray updated their 2009 Atlantic Hurricane Season Outlook. The good news is that they have slightly decreased their numbers and are now calling for 11 named storms, of which five will be hurricanes, and two will be major hurricanes. They foresee a slightly below-average Atlantic basin hurricane season due to the persistence of anomalously cool sea surface temperatures (SST) in the tropical Atlantic and the stronger-than-normal Azores High during April-May. They note that the SST anomaly values are the lowest that have been observed since June-July 1994. The stronger-than-normal Azores High typically results in stronger trade winds that are commonly associated with less active hurricane seasons. Klotzbach and Gray say another reason for their reduction in today’s forecast from earlier forecasts is their belief in an increased probability of a weak El Nino developing by the most active porton of the season.
Klotzbach and Gray make it very clear that their statistical scheme will fail in some years and that they do not specifically predict where within the Atlantic basin these storms will strike. All coastal residents should prepare for hurricane season every year given that it only takes one landfalling system to make for a very active season for you.
The figure below shows a good example of why it is not all about the numbers.
1992 was a well-below average year number wise, with only six tropical storms and one subtropical storm – well below the average of 11 named storms. And there was only one hurricane that made landfall in the United States that year – shown in the figure by the track across South Florida into Louisiana . That track belongs to Hurricane Andrew – one of the costliest hurricanes on record. It only takes one. We need to be prepared no matter what the seaonal outlooks indicate.