Information obtained through May 2009 indicates that the 2009 Atlantic hurricane season will be slightly less active than the average 1950-2000 season. We estimate that 2009 will have about 5 hurricanes (average is 5.9), 11 named storms (average is 9.6), 50 named storm days (average is 49.1), 20 hurricane days (average is 24.5), 2 major (Category 3-4-5) hurricanes (average is 2.3) and 4 major hurricane days (average is 5.0). The probability of U.S. major hurricane landfall is estimated to be slightly below the long-period average. We have decreased our seasonal forecast from early April (information provided by Dr. Philip J. Klotzbach and Dr. William M. Gray).
Here is a list of reasons for a less than active hurricane season. All inhibit the development of hurricanes. 1). More vertical wind shear due to weak El Nino conditions. 2). Cooler sea surface temperatures in the Tropical Atlantic. 3) Stronger trade winds due to a very strong Azores High.
