Talk:Beaufort scale

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Untitled[edit]

I learned to use the beaufort scale in 1941 while plotting daily synoptic charts in the Army Air Corps at Kelly Field, Tx. This is very good.jonhays 00:35, 19 Sep 2003 (UTC)

Expansion/variation[edit]

Although metric measures are probably a better choice, should I also include the US Imperial measures? (ie: wave heights in feet 0, 0, 0-1, 1-2, 2-4, 4-8, 8-13, 13-20, 13-20, 13-20, 20-30, 30-45, and 45+) Also, there is a corresponding sea state scale, 0-9, which is common in North America due to its use in Bowditch and inclusion in Navy logs. - Amgine 18:44, 26 Nov 2004 (UTC)

I think the table can be extended according to section E of this document. Momoko

km/h as opposed to m/s[edit]

Is it common (and if so, where) to denote wind speeds in km/h? In my native Sweden, I have only ever seen m/s (and of course knots in nautical contexts). It may well be that in other parts of the world, km/h is used instead, but if not, I think the table should give values in m/s (first because it's the SI unit), knots, and mph. -- Jao 19:16, May 29, 2005 (UTC)

Of the three countries I've lived in, weather forecasts in two (Germany and Canada) use km/h, while one (Britain) uses the Beaufort scale itself. I've not seen m/s, although I'm sure it is standard in scientific contexts, and as you say in Sweden! I added km/h as I thought it would be more intuitively intelligible to the majority of readers; even if they're not familiar with wind measurements in km/h per se, most people will have some idea of what it feels like if you stick your hand out of the car window at 100km/h. I suspect anyone with a scientific inclination is capable of going to the article on knots and performing the relevant computation for themselves, but I certainly wouldn't be against adding m/s to the article as well. Best wishes, Cambyses 08:41, 30 May 2005 (UTC)

You have convinced me that km/h should stay. As to whether we could have a fourth measure, well, I won't go into that. It might become too much. -- Jao 10:01, May 30, 2005 (UTC)

In Bulgaria usually meteorolists are forecasting the winds in m/s, while news reporters on the TV are using km/h. Thus I am going to put both under single column in the Bulgarian version. -- Goldie 19:20, 24 September 2005 (UTC)

M/s is normally used in Denmark, as well, and Km/h is pretty much reserved for vehicle speeds. A scandinavian tradition, perhaps. I'd say m/s should definitely stay on the list, if nothing else, though; while it may be 'normal' for people to experience (strong) windpressure on the playful hand at high vehicle speeds, m/s seems more immediately applicable to the experience of windpressure on the whole body, and ideas of high fast you'd need to move (running) to keep up with it/ how hard work it is to walk against the wind.

Why do the km/h values have m/s after it, when there are separate m/s values? Tafenau (talk) 06:14, 19 February 2012 (UTC)

Speeds[edit]

On, 17 June 2004 21:12 speeds were change to mean speeds. I feel that this may have been misunderstood by the user who changed them because the user added a less than and greater than value to the mean speeds on the high and low ends. Are the means speeds really needed? -- 03:19, 9 Jul 2005 (UTC)

Beaufort criteria for effects on sailing ships[edit]

Ought the criteria given by Beaufort, listed at both the Met and National Weather Service websites, be given here too? There does not seem to be room in the table, but maybe there is, and at the least it could be added in a separate table on this same page. - Centrx 18:34, 15 August 2005 (UTC)

I'd support that. PeteVerdon 12:09, 14 March 2006 (UTC)

"at twelve, all sails would be stowed away" - original research?[edit]

No ship can be sailed without any sails up. In strong winds, smaller sails would be used. It seems unlikely to me that there is a direct link between the number of sails up and the wind strength on the Beaufort scale. Nor does it seem like this claim is supported by the quoted BBC reference. 89.9.81.254 (talk) —Preceding undated comment added 14:39, 18 July 2009 (UTC).

I disagree with this objection and have removed the "original research" tag. Beaufort did indeed give his scale in terms of how a man-of-war would handle under sail. Force 12 is indeed described as "that which no canvas could withstand". I have supplied a reference. We can only speculate exactly what Beaufort would recommend British captains to do in force 12. But, if no canvas can withstand the wind, the logical conclusion is to run before the rigging. In contrast to what the user claims, it is standard ship handling in strong winds to take all sails down and run with the wind. For square riggers that Beaufort cared about, there is indeed a link between wind strength and number of sails up, as is clear from Beaufort's original table, as seen in the reference I have supplied. --85.24.87.73 (talk) 18:12, 19 August 2009 (UTC)

A better reference would be the Ref 1 as it stands which I have included below from the Met Office:
http://www.metoffice.gov.uk/media/pdf/4/4/Fact_Sheet_No._6_-_Beaufort_Scale.pdf
Whilst it is true that at BS 12 no sails would be up, looking at Beaufort's criteria on sails in the above the suggestion of a linear relationship between BS and sails, as the text implied, is very misleading.
The text previously stated that at BS6 half the sails would be flown, when in fact in B's criteria all sail could be flown up to 9, given ::sufficient mast strength, back stays etc. To quote 5-9: "In which a well-conditioned man of
war, under all sail, and ‘clean full’, could just carry close hauled...".
He did alongside this note a progression of sails to be struck down and/or reefed.
Obviously the number of sails aloft is at the discretion of the master, bosun or captain. Different ships can withstand a different ::number of sails, types of sails and reefs, as well as combinations of those.
As such I have deleted the text as misleading.
A possible revision would be to copy the table from the aforementioned link.
Olivcm (talk) 10:13, 4 March 2013 (UTC)

Waves under hurricane?[edit]

I've always thought that there are big waves under a storm, but almost flat water under a hurricane, since the waves would be blown apart? Is that a myth, or? 83.93.224.223 12:24, 29 October 2005 (UTC)

Myth. Maybe in an extremely strong hurricane, but not in your every-day hurricane. - Cuivienen 02:38, 5 December 2005 (UTC)

Are there, though, recorded hurricanes that, by virtue of their unusual strength, produced high swells, like the tide - with little or no foam 24.184.234.24 (talk) 16:51, 30 May 2010 (UTC)LeucineZipper

All hurricanes generate storm surge (a lifting of the ocean due to their low pressure), and all hurricanes generate millions of foamy waves on top of the storm surge. de Bivort 17:00, 30 May 2010 (UTC)

Extension to Force 17[edit]

When was the scale extended? UK MetOffice said that the Beaufort scale was extended in 1944.[1] However, I've seen a few sources saying that it was extended in 1950's.[2][3] Which one is true? Momoko

The Nynorsk version of this page gives specific wind speeds for 13, 14, and 15. -- Evertype· 11:49, 1 December 2006 (UTC)
Found a reference which mentions a 17 level scale in 1946, but this doesn't necessarily mean it wasn't extended that year. Thegreatdr (talk) 01:35, 10 January 2009 (UTC)

Scale is a jpeg[edit]

I don't like that. So I changed it into text again. 218.168.213.149 05:33, 23 June 2006 (UTC)

"Table of degrees"[edit]

[4] would have it that there's a forerunner to the Beaufort scale, so the para At that time [...] there was no scale and so they could be very subjective might want amending. The page is already in the references. 193.62.203.214 15:27, 19 July 2006 (UTC)

Wind speed formula and deleted section[edit]

There was an uncommended deletion of the paragraph that contains the wind speed <> Bft relationship. Since I could not see any reason for this deletion I have re-inserted it. However, the formula is empirical correct (while the factor 0.836 from the German Wikipedia seems to be a slightly better fit) but there is still need for a reference. There is the astonishing fact that the Beaufort number, if interpreted as a result of rounding to the nearest integer, is strongly correlated to the wind speed via a 3/2 power law. This is equivalent to a cubic law for the dynamic pressure of the wind. If the correct coefficient is chosen the formula matches the m/s table with an error of the order of 0.1, the usual decimal precision of the m/s values including those for Beaufort numbers 13 to 16 as tabulated in "Meyers Enzyklopädisches Lexikon" from the mid-seventies ("17" is from above "16" to infinity in that table). So it is clear that this cannot be a random correlation but an intended one. Does anyone know how the Beaufort scale speed values are initially intruduced? Maybe there is an original reference that explicitely uses a power law. If so, then this reference shoud be cited.--SiriusB 13:36, 22 January 2007 (UTC)

This table shows wind speeds for Bft 0-17 (probably equivalent to that in "Meyers Enzyklopädie"). Apparently, also the 0.837 figure yields a good fit to that.--SiriusB 13:53, 22 January 2007 (UTC)

I have checked the goodness of the both fits (0.836 and 0.837) and found that the 0.836 formula is slightly better according to the χ2 criterion (actually, the optimum is near 0.8359). Furthermore, the condition that the Bft wind speed from the formula lies between the maximum speed of a given B number and the minimum speed of the next higher B number is violated only for one number (B=15) for the 0.836 formula but for four numbers for the 0.837 formula. So, the 0.836 formula should be the preferred one (I did not test whether another power law might be better).--SiriusB 14:30, 22 January 2007 (UTC)

Finally, I have found something. The Beaufort scale has indeed been defined by the 0.836 formula, namely after its 1946 (not 1944 according to [5]) revision and extension.

http://www.numericana.com/answer/scales.htm uses the value 0.8365 for a consistent Beaufort scale. —Preceding unsigned comment added by 91.153.61.242 (talk) 08:39, 2 February 2008 (UTC)
I added the formula probably a few years ago by now. Fitting the 3/2 power law is intentional in development of the formula, although was apparently incidental in the original scale. It was found some decades later to correspond to the 3/2 power law then the scale was refined to better match it. The .837 figure may be explained by lack of robustness at that time which then propagated through the years, although I don't remember the details and haven't run the numbers myself. The source for my figure as I recall was a Terence Meaden paper on the TORRO scale which has its basis in the Beaufort scale. An original source may be preferable, I'll look back at the Meaden paper and its references, and maybe also try a literature search. In the meantime, the (UK) Met Office page uses the converted 1.87*sqrt(B³) figure. Evolauxia (talk) 09:53, 2 February 2008 (UTC)
My understanding is that the Beaufort scale is defined in terms of the state of the sea surface, and not wind speed. That's way I placed the [dubious ] tag. I'll dig around for a reference. Thunderbird2 (talk) 10:50, 2 February 2008 (UTC)
These are relevant:
Thunderbird2 (talk) 10:55, 2 February 2008 (UTC)

Image[edit]

I believe an image near the top of the page makes an article look nicer. I've added a cut version of the force 12 picture (cut: without the text underneath). An anonymous user has deleted it, and I now reinstate it once so we can discuss here whether a picture is appropriate, and if so, whether this is a suitable picture. Classical geographer 20:04, 17 August 2007 (UTC)

Yeah, it's good. Anon edit could well have been vandalism or a test. Debivort 03:00, 18 August 2007 (UTC)

Beaufort scale in the North Atlantic[edit]

For simplicity, why not just peg Beaufort forces 12 through 16 to the Saffir-Simpson hurricane scale? -- Denelson83 01:07, 12 October 2007 (UTC)


Mean winds?[edit]

Does anyone know what 'mean' wind speed is meant? Is it the 10 minute mean that is common now or the one hour mean wind that used to be more common? Subsea (talk) 15:01, 27 February 2008 (UTC)


Hurricane Force[edit]

I think it needs a mention that a force 12 wind - hurricane force - is not the same as a hurricane. —Preceding unsigned comment added by 92.8.194.2 (talk) 08:36, 10 August 2008 (UTC)

Difference in article[edit]

The wind speed in the scale for force 4 is 20 – 28 knots, yet in the image its 11 - 16 knots. Seems to be different in almost all of them, something wrong here? —Preceding unsigned comment added by 87.198.161.74 (talk) 15:51, 6 July 2009 (UTC)

What's going on in this article? Is it even correct?[edit]

Compare this article with the same scale described at Tropical_cyclone_scales#Comparisons_across_basins and Wind#Wind_force_scale. It seems like the modern Beaufort scale goes to 17. Jason Quinn (talk) 04:26, 4 March 2010 (UTC)

new format[edit]

I think the new table looks fine, but I wouldn't suggest adding any more images to it. Might as well stay with the consistently formatted set. de Bivort 22:40, 28 April 2010 (UTC)

Sub-article[edit]

The article has red links to every possible wind speed. I would be glad to create articles for some of them, but wonder if all they meet criteria for WP:Notability. Also every name given to that speed contains a link, which may tempt editors to create redundant articles. Already articles have been made lacking verifiable material. Let me know if you have solutions. 24.184.234.24 (talk) 17:15, 18 May 2010 (UTC)LeucineZipper

White horses[edit]

From the wind scale table we learn that a Moderate breeze has this effect on the water surface : Small waves with breaking crests. Fairly frequent white horses.

Now I wanted to find out what "white horses" could mean, so I clicked the link to find the page wind wawe, with no explanation whatsoever. Going to the page White Horse doesn't give me a clue either ...

And I do not ask just to get an answer here, I'd expect an explanation with some reference in the articles. Anyone? Thank you from no.wiki user TorSch (talk) 08:16, 7 November 2010 (UTC)

Wikipedia is WP:NOT#DICTIONARY and there is no reason to expect it to contain an explanation of every term used. Isn't that what a dictionary is for? --candyworm (talk) 13:55, 11 November 2010 (UTC)
OK, so as long as I am stupid (or Norwegian) enough NOT to know what the expression means, I shall be kept from learning? Aren't ALL links a help to let us understand what's in a word or an expression? Now I happen to understand the meaning of both breeze and gale - aren't THEY explanations of a term or a word just as well? The link white horses (see under "Moderate breeze") is a blue link, pointing to a page telling about Wind wave - and that page does not care to explain if the term refers to a kind of wave, a swimming animal or a bottle of Scotch. When a term is linked, I'd expect to learn something when I click on it. BTW, Wikipedia has articles to define a lot of words that appear obvious to most people, like water, sea, ocean, wave, day and hour. So don't try to cut me off with "Oh, it's just a term, we don't care to tell you what it means" ... Isn't that what Wikipedia is for? Rgds TorSch of Norwegian Wiki - TorSch (talk) 16:22, 14 November 2010 (UTC)
'White horses' are the prominent white areas of spray and froth that occur at the crest of waves when the wind reaches a certain speed.
They get their name because they resemble the flowing manes of galloping white horses. At the time of Beaufort most seafaring people would have been familiar with the appearance of horse's manes as the horse was still the most widely used form of land transport. — Preceding unsigned comment added by 80.7.147.13 (talk) 13:45, 17 July 2012 (UTC)

Broken links[edit]

The source page for all the images, http://www.crh.noaa.gov/mkx/ghwo/windseas_levels.php, does not exist anymore. Attys (talk) 21:36, 11 July 2011 (UTC)

Does Beaufort Scale describes sea conditions or wind speed?[edit]

Surely the purpose of the Beaufort Scale is to describe the conditions of the sea and not wind speed? Dondervogel 2 (talk) 11:27, 21 July 2011 (UTC)

No, I think it's a wind speed scale with cues taken from the sea state. If you were on a small oiled pond with 56 knot winds, it would still be force 11, even though the sea state might be pretty mild. de Bivort 01:45, 22 July 2011 (UTC)
A WMO report dated from 1970 [The Beaufort Scale of Wind Force: Technical and Operational Aspects (reports on marine science affairs, Report No. 3)] defines Force 11 as 'Exceptionally high waves (small and medium sized ships might be for a time lost to view behind the waves); the sea is completely covered with long white patches of foam lying in the direction of the wind; everywhere the edges of the wave crests are blown into froth; visibility affected'. I see no mention of wind speed there. Is there an alternative WMO definition that defines Beaufort Force in terms of wind speed? Dondervogel 2 (talk) 12:35, 22 July 2011 (UTC)
NOAA calls it the Beaufort Wind Scale: http://www.spc.noaa.gov/faq/tornado/beaufort.html, with associated conditions on land, where there is no sea state. de Bivort 19:36, 22 July 2011 (UTC)
I agree that the Beaufort scale on land differs from that at sea. I agree also that the NOAA definition of "Beaufort Scale" is relevant, but to me this table does not look to like it is intended to be used as a definition. The question then necomes, does NOAA publish something equivalent to the WMO report, with a clear description of what is meant by (eg) "Beaufort Force 11"? Dondervogel 2 (talk) 09:29, 23 July 2011 (UTC)
I found this WMO document, which seems relevant (see Appendix E) . It does mention wind speeds (though note some of these differ from those listed in the WP article), but what's not clear to me is (in the event of inconsistencies between different columns) which column is to be interpreted as definition and which columns are derived from that definition. Dondervogel 2 (talk) 11:47, 23 July 2011 (UTC)
This publication makes it clear that the scale represents wind *conditions* and not wind speed: "The original Beaufort scale of wind force is a scale that does not present the actual velocity with which the air moves. It is merely a scale of wind conditions that was used by sailors to categorize the different sailing conditions." Dondervogel 2 (talk) 10:25, 1 August 2011 (UTC)
I rephrased the opening statement to make it reflect better what it says in the references. Dondervogel 2 (talk) 18:26, 15 August 2011 (UTC)

Associated Warning Flags[edit]

I don't think these should necessarily be included in the article. The flags are part of the Coastal Warning Display Program, which is based off of warnings based off of the Beaufort scale, but it's not actually part of the Beaufort scale. I think including them may be misleading to people and make it appear that the flags are actually part of the scale. Inks.LWC (talk) 22:59, 14 August 2011 (UTC)

Severe gale[edit]

Not sure if this is worth noting, but the UK Met Office uses "severe gale" and not "strong gale" for F9. 86.132.137.179 (talk) 14:45, 11 September 2011 (UTC)

Germany[edit]

I couldn't find the information that Germany uses the extended Beaufort scale at the indicated link just added. Moreover, Beaufort-Skala from the same website strongly suggests that it does not. Carolina wren (talk) 01:48, 9 February 2014 (UTC)

Just realized that the edit was only referencing Germany's use of the basic scale. Still, I'm going to change the link, since the original link is to an index page for framed vocabulary entries. Carolina wren (talk) 01:56, 9 February 2014 (UTC)