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Beaufort Wind scale displaying wrongly
Posted: Thu 07 Jan 2016 11:49 am
by richard_newberry
The beaufort doesnt correspond with the wind speed. I have gentle breeze at F3 when getting wind speed over 12mph
Beaufort F3 is between wind speed 8-12mph, mines 15-19mph
Should be saying Beaufort F4.
Or does the Beaufort scale use wind avg then current wind speed?
i.e.
http://www.statman.info/conversions/wind_force.html
Re: Beaufort Wind scale displaying wrongly
Posted: Thu 07 Jan 2016 11:51 am
by steve
Your average wind speed is currently 13.6 mph, and Cumulus is showing F4. That's correct.
Re: Beaufort Wind scale displaying wrongly
Posted: Thu 07 Jan 2016 11:53 am
by steve
And now it's 6.9 with F2. Also correct.
Re: Beaufort Wind scale displaying wrongly
Posted: Thu 07 Jan 2016 11:53 am
by richard_newberry
steve wrote:Your average wind speed is currently 13.6 mph, and Cumulus is showing F4. That's correct.
Should it be going with speed rather then wind avg?
Re: Beaufort Wind scale displaying wrongly
Posted: Thu 07 Jan 2016 11:54 am
by steve
And now it's 7.6 with F3. Still correct.
Re: Beaufort Wind scale displaying wrongly
Posted: Thu 07 Jan 2016 11:54 am
by steve
richard_newberry wrote:Should it be going with speed rather then wind avg?
No. And the figure you are displaying as 'current wind speed' on your web site looks like the station's 'gust' value to me, which is definitely the wrong thing to determine Bft from. The wind speed figures supplied by Cumulus are defined in the FAQ.
Beaufort Wind scale displaying wrongly
Posted: Thu 07 Jan 2016 4:59 pm
by logjam
The beaufort scale is really a measure of the wind speed regards the overall effect of the wind. A single gust figure is interesting but wouldn't be an indicator of what the wind was actually doing generally to the environment. A measure of sustained force is required. The average wind speed is a better indicator of that.
Having said that, 'frequent gusts' can occasionally do more damage than an average speed might indicate. In that case a 'warning' for that beaufort descriptor is sometimes given even if the average is less than the usual figures. For instance a 'Storm Force Warning' might be given even if the average is expected to be less than 55mph, but the wind speed is expected to frequently gust around 68mph, or more. That is used for warning predictions though. AFAIK it isn't used for current or historic weather descriptions.