The National Centers for Environmental Prediction (NCEP) delivers national and global weather, water, climate and space weather guidance, forecasts, warnings and analyses to its Partners and External User Communities. The NCEP manages nine centers: Aviation Weather Center, Climate Prediction Center, Environmental Modeling Center, National Hurricane Center, NCEP Central Operations, Ocean Prediction Center, Space Weather Prediction Center, Storm Prediction Center, and Weather Prediction Center. The NCEP also provides access to the Betty Petersen Memorial Library, a branch of the NOAA Central Library, which contains a specialized meteorological and oceanographic collection of about 5,000 volumes.