Tornado Alley Sailing Club

The Sailing Club for Busy People

who like to sail or who would like to start sailing in the Memphis, Tennessee area
"Sailing Fun doesn't need to take up the whole day"

THE BEAUFORT SCALE

Long before the invention of mechanical or electronic wind meters back in 1805, a British naval officer, Francis Beaufort, developed a method for describing wind strength based on the observation of wind related phenomena. This was the Beaufort Scale. In 1830 it became the standard for the British Navy. It is still used in sailboat racing. The scale describes a whole range of wind and weather conditions from sleepy windless doldrums to gale force winds. The Beaufort wind force is factored into the Portsmouth handicap rating when we race.

Beaufort number	Wind speed		Description	Wave height	Sea conditions	Land conditions	Sea state photo
Beaufort number	mph	kts	Description	ft	Sea conditions	Land conditions	Sea state photo
0	<1	<1	Calm	0	Flat.	Calm. Smoke rises vertically.
1	1-3	1-2	Light air	0.33	Ripples without crests.	Wind motion visible in smoke.
2	3-7	3-6	Light breeze	0.66	Small wavelets. Crests of glassy appearance, not breaking	Wind felt on exposed skin. Leaves rustle.
3	8-12	7-10	Gentle breeze	2	Large wavelets. Crests begin to break; scattered whitecaps	Leaves and smaller twigs in constant motion.
4	13-17	11-15	Moderate breeze	3.3	Small waves.	Dust and loose paper raised. Small branches begin to move.
5	18-24	16-20	Fresh breeze	6.6	Moderate (1.2 m) longer waves. Some foam and spray.	Branches of a moderate size move. Small trees begin to sway.
6	25-30	21-26	Strong breeze	9.9	Large waves with foam crests and some spray.	Large branches in motion. Whistling heard in overhead wires. Umbrella use becomes difficult. Empty plastic garbage cans tip over.
7	31-38	27-33	High wind, Moderate Gale, Near Gale	13.1	Sea heaps up and foam begins to streak.	Whole trees in motion. Effort needed to walk against the wind. Swaying of skyscrapers may be felt, especially by people on upper floors.
8	39-46	34-40	Fresh Gale	18	Moderately high waves with breaking crests forming spindrift. Streaks of foam.	Twigs broken from trees. Cars veer on road.
9	47-54	41-47	Strong Gale	23	High waves (6-7 m) with dense foam. Wave crests start to roll over. Considerable spray.	Larger branches break off trees, and some small trees blow over. Construction/temporary signs and barricades blow over. Damage to circus tents and canopies.
10	55-63	48-55	Whole Gale/Storm	29.5	Very high waves. Large patches of foam from wave crests give the sea a white appearance. Considerable tumbling of waves with heavy impact. Large amounts of airborne spray reduce visibility.	Trees are broken off or uprooted, saplings bent and deformed, poorly attached asphalt shingles and shingles in poor condition peel off roofs.
11	64-72	56-63	Violent storm	37.7	Exceptionally high waves. Very large patches of foam, driven before the wind, cover much of the sea surface. Very large amounts of airborne spray severely reduce visibility.	Widespread vegetation damage. More damage to most roofing surfaces, asphalt tiles that have curled up and/or fractured due to age may break away completely.
12	≥73	≥64	Hurricane-force	≥46	Huge waves. Sea is completely white with foam and spray. Air is filled with driving spray, greatly reducing visibility.	Considerable and widespread damage to vegetation, a few windows broken, structural damage to mobile homes and poorly constructed sheds and barns. Debris may be hurled about.

Tornado Alley Sailing Club does not advise skippers to sail their boats during life-threatening atmospheric conflagrations. But if you choose to do so, we advise you to always wear a personal flotation device, use the buddy system and, of course, have fun.