Dynamic Hurricane Season Prediction with the NCEP T382 CFS CGCM

Dynamic Hurricane Season Prediction with the NCEP T382 CFS CGCM Jae-Kyung E. Schemm and Lindsey Long Climate Prediction Center, NCEP/NWS/NOAA Since 2009, the Climate Prediction Center has utilized the T382 CFS CGCM forecasts as part of the procedures employed for the Atlantic and Eastern North Pacific hurricane season outlooks. The T382 CFS has shown to have a robust climatological cycle of tropical cyclones (TC) and fair level of skill in predicting the interannual variability of TC numbers over the three Northern Hemisphere ocean basins. The prediction assessments were made based on a series of experimental forecast runs with the T382 CFS CGCM for the storm season of May through November. The experimental runs were made with initial conditions in mid-April during 1981-2008 in the T382 spectral resolution to evaluate tropical storm statistics in the CFS at the highest possible spatial resolution. Tropical storms in the CFS runs were identified using the tropical storm detection method devised by Carmago and Zebiak (2002). Storms depicted in the CFS have very realistic tracks in all three basins in the Northern Hemisphere and robust seasonal cycles. Comparisons of interannual variability in storm activities indicate that the CFS has reasonable skill and captures the shift to a more active storm era in the Atlantic basin during the post-1995 period. The 2010 season prediction based on the real time forecast runs of the T382 CFS will be discussed along with the verification of the 2009 storm season.