ForWarn is a satellite-based forest disturbance monitoring system for the conterminous United States. It delivers new forest change products every eight days and provides tools for attributing abnormalities to insects, disease, wildfire, storms, human development or unusual weather. Archived data provide disturbance tracking across all lands since 2000. Interactive maps are accessible via the Forest Change Assessment Viewer.

The Assessment Viewer is an online geospatial tool delivering phenological data products to better understand landscape conditions and to warn of potential forest disturbances. The Assessment Viewer includes an archive of frequently updated ForWarn national disturbance maps and other related data. Users can compare disturbance maps through time, and share findings of potential forest disturbances with other interested users.