Storm Spotter Field Guide
Basic Weather Spotter Field Guide
https://www.weather.gov/media/oun/spottertraining/basicspotterguide.pdf
Advanced Weather Spotter Field Guide
https://www.weather.gov/media/oun/spottertraining/advancedspotterguide.pdf
Other Weather Spotter Reference Materials
https://www.weather.gov/oun/spotter-referencematerials