FACTOID # 20: Statistically, Delaware bears more cost of the US Military than any other state.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Beaufort scale
Force 12 at sea.
Force 12 at sea.

The Beaufort scale is an empirical measure for describing wind velocity based mainly on observed sea conditions. Its full name is the Beaufort wind force scale. A central concept in science and the scientific method is that all evidence must be empirical, or empirically based, that is, dependent on evidence or consequences that are observable by the senses. ... For other uses, see Wind (disambiguation). ... This article or section does not adequately cite its references or sources. ...

Contents

History

The scale was created in 1805 by Sir Francis Beaufort, an Irish-British admiral and hydrographer. But the scale that carries Beaufort's name has a long and complex evolution, reaching farther back in history to others, and further forward as well, to when Beaufort was a top administrator in the Royal Navy in the 1830s. 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 getting things standardized. Thomas Jefferson. ... Rear-Admiral Sir Francis Beaufort, FRS, FRGS (7 May 1774 – 17 December 1857) was an Irish hydrographer and officer in the British Royal Navy. ... Hydrography is the measurement of physical characteristics of waters and marginal land. ...


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 man of war, then the main ship of the Royal Navy, from "just sufficient to give steerage" to "that which no canvas sails could withstand." At zero, all his sails would be up; at six, half of his sails would have been taken down; and at twelve, all sails would be stowed away.[1] This article or section does not adequately cite its references or sources. ... A man of war (also man-of-war, man-o-war or simply man) is an armed naval vessel. ... This article is about the navy of the United Kingdom. ... A sail is a surface intended to generate thrust by being placed in a wind; basically it is a vertically oriented wing. ...


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 1906, 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, Director of the UK Meteorological Office, was responsible for this and for the addition of the land-based descriptors.[2] The measure was slightly altered some decades later to improve its utility for meteorologists. Today, many countries have abandoned the scale and use the SI-based units m/s or km/h instead,[citation needed] but the severe weather warnings given to public are still approximately the same as when using the Beaufort scale. A hemispherical cup anemometer of the type invented in 2000 by John Thomas Romney Robinson An anemometer is a device for measuring the velocity or the pressure of the wind, and is one instrument used in a weather station. ... George Clarke Simpson (1878–1965) was a British meteorologist. ... Categories: Stub | Geography of the United Kingdom ... Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting. ... Look up si, Si, SI in Wiktionary, the free dictionary. ... NOAA scientists observe severe weather using a mobile doppler radar and a helicopter (in the distance) Severe weather phenomena are weather conditions that are hazardous. ...


The Beaufort scale was extended in 1946, when Forces 13 to 17 were added. However, Forces 13 to 17 were intended to apply only to special cases, such as tropical cyclones. Nowadays, the extended scale is only used in Taiwan and mainland China, which are often affected by typhoons.


Wind speed on the 1946 Beaufort scale is based on the empirical formula:[3]

v = 0.836 B3/2 m/s

where v is the equivalent wind speed at 10 metres above the surface and B is Beaufort scale number. For example, B = 9.5 is related to 24.5 m/s which is equal to the lower limit of "10 Beaufort". Using this formula the highest winds in hurricanes would be 23 in the scale. Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector), defined by distance in metres divided by time in seconds. ...


Today, hurricanes are sometimes described as Beaufort scale 12 through 16, very roughly related to the standard Saffir-Simpson Hurricane Scale where Category 1 is equivalent to Beaufort 12. However, the Saffir-Simpson Scale does not match the extended Beaufort numbers above 13. Category 1 tornadoes on the Fujita and TORRO scales also begin roughly at the end of level 12 of the Beaufort scale but are indeed independent scales. This article is about weather phenomena. ... The Saffir-Simpson Hurricane Scale is a scale classifying most Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms, and thereby become hurricanes. ... This article is about the weather phenomenon. ... F-scale redirects here. ... The TORRO tornado intensity scale (or T-Scale) is a scale measuring tornado intensity between T0 and T10. ...


Note that wave heights in the scale are for conditions in the open ocean, not along shore. Animated map exhibiting the worlds oceanic waters. ...


The modern scale

Beaufort number Wind speed Mean wind speed (kn / km/h / mph) Description Wave height Sea conditions Land conditions Sea state photo
kn km/h mph m/s m ft
0 0 0 0 0-0.2 0 / 0 / 0 Calm 0 0 Flat. Calm. Smoke rises vertically.
1 1-3 1-6 1-3 0.3-1.5 2 / 4 / 2 Light air 0.1 0.33 Ripples without crests. Wind motion visible in smoke.
2 4-6 7-11 4-7 1.6-3.3 5 / 9 / 6 Light breeze 0.2 0.66 Small wavelets. Crests of glassy appearance, not breaking Wind felt on exposed skin. Leaves rustle.
3 7-10 12-19 8-12 3.4-5.4 9 / 17 / 11 Gentle breeze 0.6 2 Large wavelets. Crests begin to break; scattered whitecaps Leaves and smaller twigs in constant motion.
4 11-15 20-29 13-18 5.5-7.9 13 / 24 / 15 Moderate breeze 1 3.3 Small waves. Dust and loose paper raised. Small branches begin to move.
5 16-21 30-39 19-24 8.0-10.7 19 / 35 / 22 Fresh breeze 2 6.6 Moderate (1.2 m) longer waves. Some foam and spray. Smaller trees sway.
6 22-27 40-50 25-31 10.8-13.8 24 / 44 / 27 Strong breeze 3 9.9 Large waves with foam crests and some spray. Large branches in motion. Whistling heard in overhead wires. Umbrella use becomes difficult.
7 28-33 51-62 32-38 13.9-17.1 30 / 56 / 35 Near Gale/Moderate gale 4 13.1 Sea heaps up and foam begins to streak. Whole trees in motion. Effort needed to walk against the wind.
8 34-40 63-75 39-46 17.2-20.7 37 / 68 / 42 Fresh Gale 5.5 18 Moderately high waves with breaking crests forming spindrift. Streaks of foam. Twigs broken from trees. Cars veer on road.
9 41-47 76-87 47-54 20.8-24.4 44 / 81 / 50 Strong Gale 7 23 High waves (6-7 m) with dense foam. Wave crests start to roll over. Considerable spray. Light structure damage.
10 48-55 88-102 55-63 24.5-28.4 52 / 96 / 60 Whole Gale/Storm 9 29.5 Very high waves. The sea surface is white and there is considerable tumbling. Visibility is reduced. Trees uprooted. Considerable structural damage.
11 56-63 103-119 64-73 28.5-32.6 60 / 112 / 70 Violent storm 11.5 37.7 Exceptionally high waves. Widespread structural damage.
12 64-80 120 74-95 32.7-40.8 73 / 148 / 90 Hurricane 14+ 46+ Huge waves. Air filled with foam and spray. Sea completely white with driving spray. Visibility greatly reduced. Considerable and widespread damage to structures.

The scale is used in, and may be most recognizable to some from, the Shipping Forecasts broadcast on BBC Radio 4 in the United Kingdom. A knot is a unit of speed abbreviated kt or kn. ... Kilometre per hour (American spelling: kilometer per hour) is a unit of both speed (scalar) and velocity (vector). ... Miles per hour is a unit of speed, expressing the number of international miles covered per hour. ... Metre per second (U.S. spelling: meter per second) is an SI derived unit of both speed (scalar) and velocity (vector), defined by distance in metres divided by time in seconds. ... This article is about the unit of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... Édouard Manet. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Look up Breeze in Wiktionary, the free dictionary. ... Image File history File links No higher resolution available. ... Look up Breeze in Wiktionary, the free dictionary. ... Image File history File links No higher resolution available. ... Look up Breeze in Wiktionary, the free dictionary. ... Image File history File links No higher resolution available. ... Look up Breeze in Wiktionary, the free dictionary. ... Image File history File links No higher resolution available. ... Look up Breeze in Wiktionary, the free dictionary. ... Image File history File links No higher resolution available. ... This article does not cite any references or sources. ... Image File history File links No higher resolution available. ... This article does not cite any references or sources. ... Image File history File links No higher resolution available. ... This article does not cite any references or sources. ... Image File history File links No higher resolution available. ... This article does not cite any references or sources. ... For other uses, see Storm (disambiguation). ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... This article is about weather phenomena. ... Image File history File links No higher resolution available. ... The Shipping Forecast is a four-times-daily BBC radio broadcast of weather reports and forecasts for the seas around the coasts of Britain and Ireland. ... old Radio 4 logo BBC Radio 4 is a UK domestic radio station which broadcasts a wide variety of spoken-word programmes including news, drama, comedy, science and history. ...


This scale is also widely used in China, Taiwan, Hong Kong and Macau, however with some differences between them. Taiwan uses the Beaufort scale with the extension to 17 noted above. China also switched to this extended version without prior notice on the morning of May 15, 2006[4], and the extended scale was immediately put to use for Typhoon Chanchu. Hong Kong and Macau however keep using Force 12 as the maximum. Lowest pressure 910 mbar (hPa) Damages $482 million (2006 USD) Fatalities 93 direct Areas affected Philippines, Taiwan, southeast China, Japan Part of the 2006 Pacific typhoon season Super Typhoon Chanchu (named Super Typhoon Caloy by PAGASA) was the second tropical storm, first typhoon, and first super typhoon of the 2006...


In the United States, winds of Beaufort 6 or 7 result in the issuance of a small craft advisory, with force 8 or 9 winds bringing about a gale warning, 10 or 11 a storm warning (or "tropical storm warning" for 8 to 11 if related to a tropical cyclone), and anything to 12 a hurricane warning. A small craft advisory is a type of warning issued by the National Weather Service in the United States, most frequently in coastal areas. ... It has been suggested that this article or section be merged with Severe weather terminology. ... See Severe weather terminology for a comprehensive article on this term and related weather terms. ... Warnings and watches are two levels of alert issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of Tropical Storm or Hurricane intensity. ... Cyclone Catarina, a rare South Atlantic tropical cyclone viewed from the International Space Station on March 26, 2004 Hurricane and Typhoon redirect here. ... Warnings and watches are two levels of alert issued by national weather forecasting bodies to coastal areas threatened by the imminent approach of a tropical cyclone of Tropical Storm or Hurricane intensity. ...


References

  • Huler, Scott (2004). Defining the Wind: The Beaufort Scale, and How a 19th-Century Admiral Turned Science into Poetry. Crown. ISBN 1-4000-4884-2. 
  1. ^ BBC - Weather Centre - Features - Understanding Weather - Beaufort Scale
  2. ^ Met Office: The Beaufort scale
  3. ^ Tom Beer (1997). Environmental Oceanography. CRC Press. ISBN 0849384257. 
  4. ^ 昨日实行新标准“珍珠”属强台风_新闻中心_新浪网

See also

The American Practical Navigator , written by Nathaniel Bowditch, is an encyclopedia of navigation, a valuable handbook on oceanography and meteorology, and contains useful tables and a maritime glossary. ... The Saffir-Simpson Hurricane Scale is a scale classifying most Western Hemisphere tropical cyclones that exceed the intensities of tropical depressions and tropical storms, and thereby become hurricanes. ... The Douglas Sea Scale is a scale which measures the height of the waves and also measures the swell of the sea. ... The Enhanced Fujita Scale, or EF Scale, is the scale for rating the strength of tornadoes in the United States estimated via the damage they cause. ... F-scale redirects here. ... The TORRO tornado intensity scale (or T-Scale) is a scale measuring tornado intensity between T0 and T10. ... There are very few or no other articles that link to this one. ... Sea state refers to the height, period, and character of waves on the surface of a large body of water. ...

External links

  • UK Meteorological Office: The Beaufort Scale
  • Investigating Clouds, a lesson plan from the National Science Digital Library that uses the Beaufort Scale.
  • Radio interview with Scott Huler.
  • OceanWeather.com gives current graphics for wind, waves and temperature
  • Open Source Textbook at Oceanworld.tamu.edu cites the original definition formula in chapter 4
  • Howtoon Poster showing effects on land/sea effects at each step.

  Results from FactBites:
 
Met Office: The Beaufort scale (1502 words)
In this article, formulation of the scales was attributed to Beaufort, and the versions of the scales discussed were identical to those introduced later by the Admiralty in a memorandum issued in December 1838 to 'all Captains and Commanding Officers of Her Majesty's Ships and Vessels'.
Beaufort's scale of wind force was revised in 1874 to reflect changes in the rig of warships, and expanded two decades later to include particulars of the sail required by fishing smacks.
The scale for seafarers, however, is no more than 'a guide to show roughly what may be expected on the open sea, remote from land' - to quote from the warning that used to be attached to the copies of the scale issued to marine observers.
Beaufort scale (198 words)
The Beaufort scale is an empirical measure for the intensity of the weather based mainly on wind power, it full name is thus the Beaufort wind force scale.
The scale was made a standard part of log entries for Royal Navay vessels in the late 1830s.
The scale was adapted to non-naval use from the 1850s, with the Beaufort numbers being tied to cup anemometer rotations.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m