Bresser My first Weather Station Mode D'emploi page 16

The Beaufort Wind Scale
The Beaufort scale is a measure for the intensity of the weather based mainly on wind power.
The scale was created by the British naval commander Sir Francis Beaufort around 1806.
WInd speed in
Beaufort
number
MPH
0 <1
1 1-3
2 4-7
3 8-12
4 13-18
5 19-24
6 25-31
7 32-38
8 39-46
9 47-54
10 55-63
11 64-72
12 > 72
16
Knots Description
<1 Calm
1 - 3 Light Air
4 - 6 Light breeze
7 - 10 Gentle breeze
11 - 16 Moderate breeze
17-21 Fresh breeze
22-27 Strong breeze
28-33 Near gale
34-40 Gale
41-47 Severe gale
48-55 Storm
56-63 Violent storm
> 63 Hurricane
Wind Characteristics
Sea conditions
Flat
Ripples without crests
Small ripples
Large ripples
Small waves
Moderate longer waves
Large waves with foam crests
Sea heaps up and foam begins
to streak
Moderately high waves with
breaking crests
High waves with dense foam
Very high waves. The sea
surface is white
Exceptionally high waves
Sea completely white with
driving spray.
Land conditions
Calm
Wind motion visible in smoke
Leaves rustle
Smaller twigs in constant motion
Small branches begin to move
Smaller trees sway
Large branches in motion
Whole trees in motion
Twigs broken from trees
Light structure damage
Trees uprooted. Considerable struc-
tural damage
Widespread structural damage
Massive and widespread damage to
structure