In message .com,
Richard Dixon writes

Norman Lynagh wrote:

Definitions on land are somewhat different. A gale is deemed to have
occurred on land if the mean speed is 34 knots or more for a period of
at least 10 minutes (at least I think that is the current UKMO
definition - others may know better)

Interesting - I think this rings a bell with another thread in the
past. Certainly suggests that "hurricane force" winds measured over
land have different definitions in the UK and US: UK measuring by
10-min sustained and US measuring by 1-min sustained. I've seen a 1.12
factor for converting between the two that suggests a UK sustained wind
of 66mph (about 57kt) would probably be around hurricane force in US
"money".

Richard

Yes, the subject is bedevilled by confusion over the different
definitions used in different parts of the world and even different
definitions used by various bodies in the same country. There is no
"correct" system, which means that it is very important to make it clear
what definitions are being used on any particular occasion.

Norman
(delete "thisbit" twice to e-mail)
--
Norman Lynagh Weather Consultancy
Chalfont St Giles 85m a.s.l.
England