I don't want to be too dogmatic on this topic, mainly because I have
been away from issuing both sea and land warnings for over 4 years
now, and inevitably things change. Therefore read on with that caveat
in mind:....

Here some thoughts though based on my experience, web pages on the Met
Office site and other sources.

First, the criteria for *gusts* are still available in the Glossary
under each heading (Gale, Severe Gale and Storm): use this link:-

http://booty.org.uk/booty.weather/uswfaqfr.htm
[ use the detailed index ]

However, as has been made clear, these were, as far as I am aware,
introduced for the convenience of bench MARINE forecasters to define
and analyse situations where gales (or higher) were
expected/occurring, and are based on the well-known "Ratio of maximum
gust to mean hourly speed for open sea" relationship [Shellard], of
*1.3.
Whether it is *right* to use this I'll leave to others to debate, but
for practical purposes, and over *OPEN* sea (i.e. within the domain of
the Shipping Forecast / High Seas etc.), then they proved a useful
guide.

The first complication arises because the Shipping Forecast is *not*
intended for inshore waters use, where of course the wind regime can
differ markedly, both in terms of the mean speed and gust structure,
than that found beyond 12 miles out. (I can't remember if the limit
was 6 or 12 miles - I think the latter as the Inshore Waters forecast
explicitly defined it's range as up to 12 miles from shore.)

They were NOT intended to be used in the post-analysis of events for
climatology or similar as is clear in the complete absence of the
mention of gusts in this table:-

http://www.metoffice.gov.uk/weather/...fortscale.html

However, annoyingly (to me at any rate), they *were* used in the gale
warning verification scheme.

The Beaufort Scale was not originally intended for land use: for a
history, see he-

http://www.metoffice.gov.uk/educatio.../beaufort.html

but as that text makes clear, early in the 20th century, a
'land-based' form was developed. Again, as far as I am aware, gust
speeds were not explicitly involved.

The problem comes, literally, as you come closer inshore, and
certainly when dealing with wind behaviour over land.

Offices with responsibility for coastal/sea area warnings (e.g.
Dunstable then Bracknell then Exeter & the various MMOs/Weather
Centres) would have the scale in front of them with the 'gust
equivalents', but they would also be issuing public service scripted
forecasts; there was a certain amount of 'leakage' from the scale
designed for use with the marine community in mind and the procedures
for land use.

The phrase "gusts to gale force" has never been officially sanctioned,
as it is meaningless. Gale force, whether used over the sea or over
land, is defined as a *mean* wind speed for a defined period of time,
usually 10 minutes. The phrase was often used when I started PS work
in the 1970s, but even then attempts were made to stamp it out, and I
thought we'd got rid of it completely with an *explicit* instruction
to mention specific values for gusts rather than vague (to the public)
terms such as 'severe gales'. Indeed, as was pointed out, the PS
definition of a 'severe gale' is nothing like that for the Beaufort
Scale:-

http://www.metoffice.gov.uk/weather/..._warnings.html

Using this definition (repeated gusts to 70 mph or more), you would be
into F11 on the *marine / operational* version of the Beaufort Scale,
whereas that scale's 'Severe Gale Force 9' would have gusts 47 to 54
mph: so there is no linkage between the two there. It gets even worse
with 'Storms', but you get the idea.

--
Martin Rowley
E:
W: booty.org.uk