National Association of Storm Chasers and Spotters
Formed in 1999, NASCAS's main mission is to provide accurate safety and educational information to the public, educators, media, government officials, students and to those who actually pursue severe weather. With the current influx of new chasers and spotters, the organization provides critical that information and ideas concerning safety and responsibility for new chasers and the spotter's learning process.
SKYWARN™ is a concept developed in the early 1970s that was intended to promote a cooperative effort between the National Weather Service and communities. The emphasis of the effort is often focused on the storm spotter, an individual who takes a position near their community and reports wind gusts, hail size, rainfall, and cloud formations that could signal a developing tornado. Another part of SKYWARN™ is the receipt and effective distribution of National Weather Service information.
Texas Severe Storms Association
The Texas Severe Storms Association (TESSA) is a 501(c)(3) national non-profit organization founded to bring together both amateur and professional severe weather scientists in an attempt to better understand dangerous storms through the collection and diffusion of knowledge. The site also offers significant "Tornado Alley" forecasts.
The Tornado and Storm Research Organization
Maintained by the the Tornado and Storm Research Organization, this site offers a wealth of research information on severe climatic changes. You'll find informational resources, photo galleries and other content.
Tornado Project Online
Since 1970, The Tornado Project has been locating, organizing and publishing information, including tornado videos, The site also offers a wide range of resources including tornado oddities, myths and an online store with everything from hats and posters to books and DVDs.
WeatherMatrix is a worldwide organization with over 10,000 amateur and professional weather enthusiasts -- meteorologists, storm chasers and spotters, and weather observers from around the globe.