Beaufort Scale	Wind Velocity (knots)	Seaman’s Term	Sea Condition	Typical Wave Height (feet)	Effect on Land
0	0 – 1	Calm	Glassy-smooth, mirror-like	Smooth	Smoke rises straight up.
1	2 – 3	Light Air	Scale-Like, ripples	Ripples	Smoke drifts, leave barely move
2	4 – 6	Light breeze	Small, short wavelets with glassy crests	1/3	Leaves rustle slightly, wind felt on face
3	7 – 10	Gentle breeze	Large wavelets, crests begin to break	1 – 2	Leaves and twigs move, loose paper and dust raised from ground
4	11 – 16	Moderate breeze	Small waves, some white caps	2 – 3	Small branches move, wind raises dust and paper
5	17 – 21	Fresh breeze [SMALL CRAFT ADVISORY]	Moderate longer waves, better formed, many whitecaps, foam and spray	3 – 4	Small trees sway and large branches in motion, dust clouds raised
6	22 – 27	Strong breeze	Large waves form, many whitecaps, foam and spray	4 - 5	Large branches move continuously; wind whistles; umbrellas difficult to use
7	28 – 33	Moderate gale	Sea heaps up, streaks of foam spindrifts begins	5 – 6	Whole trees in motion, difficult to walk
8	34 – 40	Fresh gale [GALE WARNING]	Moderately-high long waves, crests into spindrift, well-marked streaks of foam	6 – 7	Tree twigs break; walking progress slow
9	41 – 47	Strong gale	High waves, sea rolls, dense streaks, spray effects visibility	7 – 9	Slight structure damage
10	48 and up	[Storm Warning]	Very high waves, long overhanging crests	10 plus	Exposed trees uprooted, heavy structure damage