Beaufort Scale of Wind Force Sometimes people or manufacturers use the Gale Force description to describe the performance potential of products or fabrics in extreme conditions.
The observable land effects is a useful guide to be able to describe conditions more accurately.
Here's a brief breakdown of the scale and the associated wind strength associated with it.
Scale | Force Rating | Observable Land Effects | Speed MPH |
0 | Calm | Vertical Smoke | 1 |
1 | Light Air | Slight smoke drift | 1-3 |
2 | Light Breeze | Leaves gently rustle | 4-7 |
3 | Gentle Breeze | Leaves and twigs move | 8-12 |
4 | Moderate Breeze | Raises paper moves small branches | 13-18 |
5 | Fresh Breeze | Sways small leafy trees | 19-24 |
6 | Strong Breeze | Sways large branches | 25-31 |
7 | Moderate Gale | Trees sway | 32-38 |
8 | Fresh Gale | Broken twigs, walking impeded | 39-46 |
9 | Strong Gale | Chimneys, slates, hoardings damaged | 47-54 |
10 | Whole Gale | Trees Blown Down and Considerable damage | 55-63 |
11 | Storm | Major Damage | 64-75 |
12 | Hurricane | Very dangerous tropical whirling winds | 76+ |