At a camp out, I was asked to guesstimate wind speed. I admitted that I had no idea, but took a crack at it, and I was probably wrong. I remembered this handy scale, and thought I'd find it and post it here. It won't be on the test.
Beaufort Wind Scale
Developed in 1805 by Sir Francis Beaufort, U.K. Royal Navy
| Force | Wind (Knots) |
WMO Classification |
|
||
|---|---|---|---|---|---|
| On the Water | On Land | ||||
| 0 | Less than 1 | Calm | Sea surface smooth and mirror-like | Calm, smoke rises vertically | |
| 1 | 1-3 | Light Air | Scaly ripples, no foam crests | Smoke drift indicates wind direction, still wind vanes | |
| 2 | 4-6 | Light Breeze | Small wavelets, crests glassy, no breaking | Wind felt on face, leaves rustle, vanes begin to move | |
| 3 | 7-10 | Gentle Breeze | Large wavelets, crests begin to break, scattered whitecaps | Leaves and small twigs constantly moving, light flags extended | |
| 4 | 11-16 | Moderate Breeze | Small waves 1-4 ft. becoming longer, numerous whitecaps | Dust, leaves, and loose paper lifted, small tree branches move | |
| 5 | 17-21 | Fresh Breeze | Moderate waves 4-8 ft taking longer form, many whitecaps, some spray | Small trees in leaf begin to sway | |
| 6 | 22-27 | Strong Breeze | Larger waves 8-13 ft, whitecaps common, more spray | Larger tree branches moving, whistling in wires | |
| 7 | 28-33 | Near Gale | Sea heaps up, waves 13-19 ft, white foam streaks off breakers | Whole trees moving, resistance felt walking against wind | |
| 8 | 34-40 | Gale | Moderately high (18-25 ft) waves of greater length, edges of crests begin to break into spindrift, foam blown in streaks | Twigs breaking off trees, generally impedes progress | |
| 9 | 41-47 | Strong Gale | High waves (23-32 ft), sea begins to roll, dense streaks of foam, spray may reduce visibility | Slight structural damage occurs, slate blows off roofs | |
| 10 | 48-55 | Storm | Very high waves (29-41 ft) with overhanging crests, sea white with densely blown foam, heavy rolling, lowered visibility | Seldom experienced on land, trees broken or uprooted, "considerable structural damage" | |
| 11 | 56-63 | Violent Storm | Exceptionally high (37-52 ft) waves, foam patches cover sea, visibility more reduced | ||
| 12 | 64+ | Hurricane | Air filled with foam, waves over 45 ft, sea completely white with driving spray, visibility greatly reduced | ||