Beaufort Wind Scale (abbreviated). National Weather Service—National Oceanic and Atmospheric Administration (NOAA). www.weather.gov/ilx/swopwindscale. The Wind Scale (Force numbers 0-12) was abbreviated to begin with wind speeds that were relevant to tree damage.
| Beaufort # | Wind speed (mph) | Wind force description | Tree impacts |
|---|---|---|---|
| 6 | 25-31 | Strong breeze | Larger tree branches moving |
| 7 | 32-38 | Near gale force | Whole tree moves |
| 8 | 39-46 | Gale force | Twigs breaking off trees |
| 9 | 47-54 | Strong gale force | Slight structural damage occurs |
| 10 | 55-63 | Storm | Tree broken up or small trees uprooted; considerable structural damage |
| 11 | 64-73 | Violent storm | Moderate sized trees uprooted; large branches snapped off trees |
| 12 | 74+ | Hurricane | Large trees and branches downed |