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Anthony Cramp
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Plan in decades. Think in years. Work in months. Live in days.

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How Windy Is It?

The measurement of wind speed has one aspect that I have always found fascinating.  The Beaufort Wind Force Scale (although it measures wind speed not force).

Back when they did not have wind speed measuring devices they needed a standard way to measure wind speed.  They came up with an empirical method, one that relies on observation and not direct measurement.  But how do you standardize such a measurement?  Francis Beaufort figured it out. 

The Beaufort Wind Force Scale (BWFS) was devised by:
The scale was devised in 1805 by Francis Beaufort (later Rear Admiral Sir Francis Beaufort), an Irish Royal Navy officer, while serving in HMS Woolwich. The scale that carries Beaufort's name had a long and complex evolution from the previous work of others (including Daniel Defoe the century before) to when Beaufort was a top administrator in the Royal Navy in the 1830s when it was adopted officially and first used during the voyage of HMS Beagle under Captain Robert FitzRoy, later to set up the first Meteorological Office (Met Office) in Britain giving regular weather forecasts. In the early 19th century, naval officers made regular weather observations, but there was no standard scale and so they could be very subjective, one man's "stiff breeze" might be another's "soft breeze". Beaufort succeeded in standardizing the scale.  ⓐ

At that time sailors needed a method for determining the speed of the wind so;
The initial scale of thirteen classes (zero to twelve) did not reference wind speed numbers but related qualitative wind conditions to effects on the sails of a frigate, then the main ship of the Royal Navy, from "just sufficient to give steerage" to "that which no canvas sails could withstand".

The scale was made a standard for ship's log entries on Royal Navy vessels in the late 1830s and was adapted to non-naval use from the 1850s, with scale numbers corresponding to cup anemometer rotations. In 1916, to accommodate the growth of steam power, the descriptions were changed to how the sea, not the sails, behaved and extended to land observations. Rotations to scale numbers were standardized only in 1923. George Simpson, C.B.E. (Later Sir George Simpson), Director of the UK Meteorological Office, was responsible for this and for the addition of the land-based descriptors. The measure was slightly altered some decades later to improve its utility for meteorologists. Today, many countries have abandoned the scale and use the metric system based units, m/s or km/h, instead, but the severe weather warnings given to the public are still approximately the same as when using the Beaufort scale.

I have always thought the descriptions of the effects of the wind sounded rather poetic, like a series of small Haiku's describing the speed of the wind.

Without further ado, I give you the Beaufort scale as in use today.

0 is Calm.  Wind speed less than 1mph.  Sea condition flat or mirror.  Land condition, smoke rises calmly.

1.  
Light air,  1-3mph.  Ripples without crests.  Smoke drift indicates wind direction. Leaves and wind vanes are stationary.

2  
Light breeze, 4-7 mph.  Small wavelets. Crests of glassy appearance, not breaking.  Wind felt on exposed skin. Leaves rustle. Wind vanes begin to move.

3.  
Gentle breeze, 8-12 mph.  Large wavelets. Crests begin to break; scattered whitecaps.  Leaves and small twigs constantly moving, light flags extended.

4.  
Moderate breeze, 13-17 mph.  Small waves with breaking crests. Fairly frequent whitecaps.  Dust and loose paper raised. Small branches begin to move.

5.  
Fresh Breeze, 18-24 mph.  Long waves begin to form. Moderate waves of some length. Many whitecaps. Small amounts of spray.  Branches of a moderate size move. Small trees in leaf begin to sway.

6.  
Strong Breeze, 25-30 mph.  Long waves begin to form. White foam crests are very frequent. Some airborne spray is present.  Large branches in motion. Whistling heard in overhead wires. Umbrella use becomes difficult. Empty plastic bins tip over.

7.  
High wind,moderate gale,near gale, 31-38 mph.  Sea heaps up. Some foam from breaking waves is blown into streaks along wind direction. Moderate amounts of airborne spray.  Whole trees in motion. Effort needed to walk against the wind.

8.  
Gale, fresh gale, 39-46 mph.  Moderately high waves with breaking crests forming spindrift. Well-marked streaks of foam are blown along wind direction. Considerable airborne spray.  Some twigs broken from trees. Cars veer on road. Progress on foot is seriously impeded.

9.  
Strong gale, 47-54 mph.  High waves whose crests sometimes roll over. Dense foam is blown along wind direction. Large amounts of airborne spray may begin to reduce visibility.  Some branches break off trees, and some small trees blow over. Construction/temporary signs and barricades blow over

10.  
Storm, whole gale, 55-63 mph.  Very high waves with overhanging crests. 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, structural damage likely.

11.  
Violent storm, 64-73 mph.  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 and structural damage likely.

12,  
Hurricane force, greater than 74 mph.  Huge waves. Sea is completely white with foam and spray. Air is filled with driving spray, greatly reducing visibility.  Severe widespread damage to vegetation and structures. Debris and unsecured objects are hurled about.

ⓐ  http://en.wikipedia.org/wiki/Beaufort_scale

http://www.spc.noaa.gov/faq/tornado/beaufort.html

http://www.unc.edu/~rowlett/units/scales/beaufort.html


Image cloudfront.net
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Did you know that today is the United Nation's International Day of Happiness???

Mashable put together a playlist full of songs to brighten your day and Say Hey (I Love You) from All Rebel Rockers is number 2 on the list! 

Go here to listen:http://mashable.com/2014/03/20/international-day-of-happiness-playlist

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Wake up Australia. Time to participate in democracy!

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Oh so THIS is what pant-wetting looks like.

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Weekly trip to Adelaide's only Indonesian grocery store.
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