BEAUFORT SCALE WIND SPEED
SCALE	WIND SPEED		WAVE HEIGHT (FEET)	DESIGNATION	DESCRIPTION
	MPH	KNOTS
0	<1	<1	0	Calm	Smoke rises vertically. Tree leaves do not move. Sea mirror calm.
1	1-3	1-3	Ripples	Light Air	Smoke drift indicates wind direction. Weather vane does not move. Ripples but without foam crests
2	4-7	4-6	0 to 4"	Light Breeze	Wind felt on face. Weather vane begins to move. Leaves rustle. Small wavelets. Crests do not break.
3	8-12	7-10	4" to 1' 8"	Gentle Breeze	Winds extends light flags. Leaves and twigs in constant motion. Large wavelets. Perhaps scattered whitecaps.
4	13-19	11-16	2-4	Moderate Breeze	Dust and loose paper raised. Small branches move. Small waves. Fairly frequent whitecaps.
5	20-24	17-21	4-8	Fresh Breeze	Small trees sway. Moderate waves. Many whitecaps.
6	25-31	22-27	8-13	Strong Breeze	Large branches move. Wind whistles in wires. Large waves begin to form. White foam crests. Probably spray.
7	32-38	28-33	13-20	Moderate Gale	Whole trees move; Walking affected. Sea heaps up and white foam blown in streaks along the direction of the wind.
8	39-46	34-40	13-20	Fresh Gale	Twigs break off trees. Walking difficult. Moderately high waves. Crests begin to break into spindrift.
9	47-54	41-47	13-20	Strong Gale	Slight structural damage occurs. Branches break. High waves. Dense foam along the direction of the wind. Crests of waves begin to roll over. Spray may affect visibility.
10	55-63	48-55	20-30	Whole Gale	Trees uprooted. Considerable structural damage. Very high waves with overhanging crest. The surface of the sea takes a white appearance. The tumbling of the sea becomes heavy and shock like. Visibility affected.
11	64-73	56-63	30-45	Storm	Widespread damage. Extremely high waves. The sea is completely covered with long white patches of foam lying in the direction of the wind. Visibility affected.
12	74+	64+	45+	Hurricane	Severe and extensive damage. The air is filled with foam and spray. Sea completely white with driving spray. Visibility very seriously affected.
1 KNOT=1.15 MPH / 1 MPH=.87 KNOTS