Incorrect terminology
In message , Norman
writes
.....
Gale Force is defined as a mean wind speed of 34-40 knots. Therefore,
the term "gusts to gale force" would actually mean "gusts to a mean
speed of 34-40 knots" which is clearly nonsense.
Sorry to be banging on about this so much but it's been a pet hate of
mine since an occasion when I had to argue the toss in Court with an
obstinate QC who insisted that a gale had occurred because there were
wind gusts to 35 knots. The outcome of the case depended on whether or
not there had been a gale. Sometimes it matters!
Quite understand the frustration with the lay unscientific approach.
I shall perhaps now add to it. I sail dinghies, along with others at a
South Coast club.
We have an anemometer with dials in the club-house showing wind
direction and speed. The race officer will make an assessment of the
wind on the water - presumably an attempt at an average - usually with a
spread of two Beaufort forces. This is duly marked on the board with the
course and other information.
Individual sailors have to decide whether to put to sea, and how to rig.
We cluster round the instruments, watching the indications for several
minutes. The usual description will be along the lines of mostly force
so-and-so from such and such a direction, and whatever speed and
whichever direction on the gusts. Accuracy is of "top end of
four-middle of five" coarseness. It is seen very much as binary. The
non-gust component of the wind should be adequate, and the gusts should
be tolerable.
We can see the state of the sea and the clouds, and usually have various
forecasts from the internet.
There will be estimates, informed by local experience, of the likely
winds on the water, away from the channelling effect of the wind round
the clubhouse and the lee of the land. Also, of course, changes in
sea-breezes and the passage of systems.
This mix of local observation and assessment is perhaps forecasting as a
craft rather than a science. Not by any means the Art of Coarse
Forecasting. Alan Watts has written compact and useful books on the
subject.
Average for modelling and scientific reporting, yes.
The harm, however, is often in the gusts.
Out of curiosity, how did the case come to turn on a gale rather than
gusts of such a speed? I hazard a guess hat it was the terms of
insurance.
--
Peter Thomas
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