Beaufort Scales (Wind Speed)

Originally found here.

Force Speed knots Speed km/h Speed mi/h Name Conditions at Sea Conditions on Land
0 < 1 < 2 < 1 Calm Sea like a mirror. Smoke rises vertically.
1 1-3 1-5 1-4 Light air Ripples only. Smoke drifts and leaves rustle.
2 4-6 6-11 5-7 Light breeze Small wavelets (0.2 m). Crests have a glassy appearance. Wind felt on face.
3 7-10 12-19 8-11 Gentle breeze Large wavelets (0.6 m), crests begin to break. Flags extended, leaves move.
4 11-16 20-29 12-18 Moderate breeze Small waves (1 m), some whitecaps. Dust and small branches move.
5 17-21 30-39 19-24 Fresh breeze Moderate waves (1.8 m), many whitecaps. Small trees begin to sway.
6 22-27 40-50 25-31 Strong breeze Large waves (3 m), probably some spray. Large branches move, wires whistle, umbrellas are difficult to control.
7 28-33 51-61 32-38 Near gale Mounting sea (4 m) with foam blown in streaks downwind. Whole trees in motion, inconvenience in walking.
8 34-40 62-74 39-46 Gale Moderately high waves (5.5 m), crests break into spindrift. Difficult to walk against the wind. Twigs and small branches blown off trees.
9 41-47 76-87 47-54 Strong gale High waves (7 m), dense foam, visibility affected. Minor structural damage may occur (shingles blown off roofs).
10 48-55 88-102 55-63 Storm Very high waves (9 m), heavy sea roll, visibility impaired. Surface generally white. Trees uprooted, structural damage likely.
11 56-63 103-118 64-73 Violent storm Exceptionally high waves (11 m), visibility poor. Widespread damage to structures.
12 64+ 119+ 74+ Hurricane 4 m waves, air filled with foam and spray, visibility bad. Severe structural damage to buildings, widespread devastation.
  • education/beaufort_scales.txt
  • Last modified: 2018/11/22 14:20
  • (external edit)