|
Beaufort Scale |
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|
Beau- |
Description |
Average wind speed at a height of 10m over open terrain |
Examples of the effects of wind in inland areas |
|
|
m/s |
km/h |
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|
0 |
Calm |
0 - 0,2 |
< 1 |
Smoke rises vertically |
|
1 |
Light air |
0,3 - 1,5 |
1 - 5 |
Direction shown by smoke drift but not by wind vane |
|
2 |
Light breeze |
1,6 - 3,3 |
6 - 11 |
Wind felt on face; leaves rustle; wind vane moved by wind |
|
3 |
Gentle breeze |
3,4 - 5,4 |
12 - 19 |
Leaves and small twigs in constant motion; light flags extended |
|
4 |
Moderate breeze |
5,5 - 7,9 |
20 - 28 |
Raises dust and loose paper; small branches moved |
|
5 |
Fresh breeze |
8,0 - 10,7 |
29 - 38 |
Small trees in leaf begin to sway; crested wavelets form on inland waters |
|
6 |
Strong breeze |
10,8 - 13,8 |
39 - 49 |
Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty |
|
7 |
High
wind, |
13,9 - 17,1 |
50 - 61 |
Whole trees in motion; inconvenience felt when walking against the wind |
|
8 |
Gale, |
17,2 - 20,7 |
62 - 74 |
Twigs break off trees; generally impedes progress |
|
9 |
Strong/severe gale |
20,8 - 24,4 |
75 - 88 |
Slight structural damage (chimney pots and slates removed) |
|
10 |
Storm, |
24,5 - 28,4 |
89 - 102 |
Seldom experienced inland; trees uprooted; considerable structural damage |
|
11 |
Violent storm |
28,5 - 32,6 |
103 - 117 |
Very rarely experienced; accompanied by widespread damage |
|
12 |
Hurricane-force |
ab 32,7 |
ab 118 |
Devastation |