NOAA's Extended-Range Atlantic Hurricane Outlooks

The National Oceanic and Atmospheric Administration (NOAA) has spearheaded a multi-faceted effort to produce reliable seasonal Atlantic hurricane outlooks at extended ranges. The program began in 1998 and is coordinated through the National Centers for Environmental Prediction (NCEP) in Camp Springs, MD. This effort was initiated in response to significant breakthroughs in our understanding and diagnosis of global climate variations and their impacts on North Atlantic hurricane activity. In particular the control of global climate patterns on regional atmospheric circulation features over the North Atlantic that are known to impact hurricane activity, such as vertical wind shear and the structure and location of the African Easterly Jet, are now established. The links between these climate patterns and tropical rainfall variations on both the interannual and interdecadal time scales are now also established. These results then provide the basis for the extended-range outlooks. The outlooks are physically based, and arise from a consensus analysis and prediction of the global climate system. A consensus determination of subsequent regional circulation features over the North Atlantic during the peak of the hurricane season then follows. This combination of local and global circulation features then provides the basis for indicating the likelihood of an active or inactive year, as well as the overall expected activity during the upcoming peak of the hurricane season. The outlooks also indicate the expected regions of storm formation, along with expected threats to the coastal United States and the Caribbean Islands.