Description of wind power
bft | m/s | km/h | kn | Label | Effects on land |
0 | 0-0,2 | 0-0,8 | 0-0,5 | Calm | Smoke rises straight up |
1 | 0,3-1,5 | 0,9-5,5 | 0,6-3,0 | Light Air | Smoke moves with wind |
2 | 1,6-3,3 | 5,6-12,1 | 3,1-6,5 | Light breeze | Weather vanes move,leaves rustle |
3 | 3,4-5,4 | 12,2-19,6 | 6,6-10,5 | Gentle breeze | Leaves and thin branches move |
4 | 5,5-7,9 | 19,7-28,5 | 10,6-15,5 | Moderate breeze | Wind raises dust and loose paper |
5 | 8,0-10,7 | 28,6-38,8 | 15,6-20,9 | Fresh breeze | Small trees begin to move |
6 | 10,8-13,8 | 38,9-49,8 | 21,0-26,9 | Strong wind | Strong branches are in motion |
7 | 13,9-17,1 | 49,9-61,7 | 27,0-33,3 | Near Gale | Trees completely in motion |
8 | 17,2-20,7 | 61,8-74,6 | 33,4-40,3 | Gale | Wind breaks branches from trees |
9 | 20,8-24,4 | 74,7-88,0 | 40,4-47,5 | Severe Gale | Damage to buildings, roof |
10 | 24,5-28,4 | 88,1-102,4 | 47,6-55,3 | Heavy storm | Weak trees are uprooted |
11 | 28,5-32,6 | 102,5-117,0 | 55,4-63,4 | Violent strom | Severe storm damage |
12 | 32,7-36,9 | 118,0-133,0 | 64,0-71,0 | Hurricane | Widespread damage to vegetation |