41 Knot gust at 19:55

37 Knot mean wind speed for the 10 minute period ending 19:56

Paul
--
www.lincolnshireweather.co.uk

In article ,
says...
41 Knot gust at 19:55

37 Knot mean wind speed for the 10 minute period ending 19:56

Paul

B....y hell! I'm just on my way home there.

Jim

It's wild back home Jim....

Paul
"Richard" wrote in message
...
In article ,
says...
41 Knot gust at 19:55

37 Knot mean wind speed for the 10 minute period ending 19:56

Paul

B....y hell! I'm just on my way home there.

Jim

Hi Paul,

I'm a bit puzzled as to why your mean is 37 knots and yet the gust is only 41
knots ? How is the mean calculated ? I would expect at least a 50 knot gust with
such a high mean speed over land ?

Will.
--
" A cup is most useful when empty "
-------------------------------------------------------------------------------
A COL BH site in East Dartmoor at Haytor, Devon 310m asl (1017 feet).

mailto:
www: http://www.lyneside.demon.co.uk

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Paul Freeman wrote in message ...
41 Knot gust at 19:55

37 Knot mean wind speed for the 10 minute period ending 19:56

Paul
--
www.lincolnshireweather.co.uk

Hi Will,

Not sure how mean is calculated - software does it for me......however,
although I am over land, I am on the coast of the Lincolnshire Fens, and the
wind has a long fetch of perfectly flat, featureless land to my west (at
least 30 miles) - would this make a difference?

Appreciate your comments

Paul
"Will" wrote in message
...
Hi Paul,

I'm a bit puzzled as to why your mean is 37 knots and yet the gust is only
41
knots ? How is the mean calculated ? I would expect at least a 50 knot
gust with
such a high mean speed over land ?

Will.
--
" A cup is most useful when empty "
--------------------------------------------------------------------------
-----
A COL BH site in East Dartmoor at Haytor, Devon 310m asl (1017 feet).

mailto:
www: http://www.lyneside.demon.co.uk

DISCLAIMER - All views and opinions expressed by myself are personal
and do not necessarily represent those of my employer.
--------------------------------------------------------------------------
-----

Paul Freeman wrote in message ...
41 Knot gust at 19:55

37 Knot mean wind speed for the 10 minute period ending 19:56

Paul
--
www.lincolnshireweather.co.uk

Will,

I've had a look at the log files, and I calculate the mean for that 10
minute period as 27 Knots - I will investigate further - however, the gust
is correct.....Does this sound more reasonable?

Regards

Paul
--
www.lincolnshireweather.co.uk
"Will" wrote in message
...
Hi Paul,

I'm a bit puzzled as to why your mean is 37 knots and yet the gust is only
41
knots ? How is the mean calculated ? I would expect at least a 50 knot
gust with
such a high mean speed over land ?

Will.
--
" A cup is most useful when empty "
--------------------------------------------------------------------------
-----
A COL BH site in East Dartmoor at Haytor, Devon 310m asl (1017 feet).

mailto:
www: http://www.lyneside.demon.co.uk

DISCLAIMER - All views and opinions expressed by myself are personal
and do not necessarily represent those of my employer.
--------------------------------------------------------------------------
-----

Paul Freeman wrote in message ...
41 Knot gust at 19:55

37 Knot mean wind speed for the 10 minute period ending 19:56

Paul
--
www.lincolnshireweather.co.uk

"Paul Freeman" wrote in message
...
Will,

I've had a look at the log files, and I calculate the mean for that 10
minute period as 27 Knots - I will investigate further - however, the
gust
is correct.....Does this sound more reasonable?

Paul,

Mean speed is often about 65% - 70% of the max gust here.

HTH,

--
Ken
http://mysite.freeserve.com/copley
kencookATcopleydurham.freeserve.co.uk


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On Sat, 31 Jan 2004 22:16:34 -0000, Paul Freeman wrote in


I've had a look at the log files, and I calculate the mean for that 10
minute period as 27 Knots - I will investigate further - however, the gust
is correct.....Does this sound more reasonable?

That would be a ratio of 41/27 or about 1.52. I have in my notes some
*typical* [1] values of gusts in relation to the *one hour* mean over flat
ground in neutral conditions. They a

10 min 1.06
1 min 1.24
30 sec 1.33
20 sec 1.36
10 sec 1.43
5 sec 1.47

I don't know how sensitive your anemometer is [2] but using the 5 second
gust in relation to the 10 minute wind gives a ratio of 1.39 which is
reasonably close to the figure I calculate for your speeds.

[1] by typical I mean average rather than on just one occasion.

[2] I'm sure yours is more responsive than just to the 5 second gust, which
would take the ratio higher than the 1.39 calculated above i.e. even nearer
the 1.52 you recorded.

--
Mike 55.13°N 6.69°W Coleraine posted to uk.sci.weather 31/01/2004 23:07:47 UTC
Temperature 2.6C

Paul,

Yes that seems about right. I was a professional observer years ago and I have
seen thousands of anemograph traces and one gets a pretty good feel for
relationships between mean and gust.

ATB and thanks for the obs,

Will.
--

Paul Freeman wrote in message ...
Will,

I've had a look at the log files, and I calculate the mean for that 10
minute period as 27 Knots - I will investigate further - however, the gust
is correct.....Does this sound more reasonable?

Regards

Paul
--
www.lincolnshireweather.co.uk
"Will" wrote in message
...
Hi Paul,

I'm a bit puzzled as to why your mean is 37 knots and yet the gust is only
41
knots ? How is the mean calculated ? I would expect at least a 50 knot
gust with
such a high mean speed over land ?

Will.
--
" A cup is most useful when empty "
--------------------------------------------------------------------------
-----
A COL BH site in East Dartmoor at Haytor, Devon 310m asl (1017 feet).

mailto:
www: http://www.lyneside.demon.co.uk

DISCLAIMER - All views and opinions expressed by myself are personal
and do not necessarily represent those of my employer.
--------------------------------------------------------------------------
-----

Paul Freeman wrote in message ...
41 Knot gust at 19:55

37 Knot mean wind speed for the 10 minute period ending 19:56

Paul
--
www.lincolnshireweather.co.uk