02 What is Windforce/Beaufort?

Beaufort scale – Wikipedia

The Beaufort scale (Bft) is a scalazur division of wind strength into 13 strength ranges from 0 – calm to 12 – hurricane, based not on exact measurements but on the observed effects of the wind. It is named after Sir Francis Beaufort and is a widely used system for describing wind strength.

According to the 1946 revision of the Beaufort scale, the following relationship exists between wind speed v and Beaufort force B [Bft] (commercially rounded):

Wind-
force
Meaningavarage Windspeed
in Bftknm/skm/hmph
0Calm0 – < 10,0 – < 0,30 – 10 – < 1,2
1Light air1 – < 40,3 – < 1,61 – 51,2 – < 4,6
2Light breeze4 – < 71,6 – < 3,46 – 114,6 – < 8,1
3Gentle breeze7 – < 113,4 – < 5,512 – 198,1 – < 12,7
4Moderate breeze11 – < 165,5 – < 8,020 – 2812,7 – < 18,4
5Fresh breeze16 – < 228,0 – < 10,829 – 3818,4 – < 25,3
6Strong breeze22 – < 2810,8 – < 13,939 – 4925,3 – < 32,2
7High wind28 – < 3413,9 – < 17,250 – 6132,2 – < 39,1
8Gale34 – < 4117,2 – < 20,862 – 7439,1 – < 47,2
9Strong gale41 – < 4820,8 – < 24,575 – 8847,2 – < 55,2
10Storm, whole gale48 – < 5624,5 – < 28,589 – 10255,2 – < 64,4
11Violent storm56 – < 6428,5 – < 32,7103 – 11764,4 – < 73,6
12Hurricane≥ 64≥ 32,7≥ 118≥ 73,6