Extreme weather sourcebook - The joint product of professional and Federal meteorological organizations, this site provides "economic and other societal impacts related to hurricanes, floods, tornadoes, lighting, and other U.S. weather phenomena." Individual state data is included.
NOAA Center for Tsunami Research - Housed at the Pacific Marine Environmental Laboratory in Seattle, this project seeks to investigate tsunami hazards to the Pacific coast of the United States and Hawaii through an integrated approach to early warning. Realtime data feeds are available from selected buoys. Sections of the site cover data on individual tsunami events, modeling and forecasting, foundation mapping efforts, and the National Tsunami Hazard Mitigation Program.
The Tornado Project Online - A corporate page with detailed listings of storm-related data such as the Fujita scale, and all tornadoes within a given calendar year beginning in 1950, arranged by state.