On Friday, 30 October 2015 09:17:54 UTC,
One thing about Dartmoor, Graham has pointed out that gale frequency has
dropped right off and it is possible that the decrease in wind speed has
decreased the orographic enhancement (which is where we get a lot of our
rain). So it is perfectly possible for rainfall to decrease or stay the
same on high ground and increase on the coast, especially in winter!
Have winds speeds decreased in Plymouth like Penzance?


Hi Len, again!

Having just read Jim's excellent response and queries in this thread, I'm
getting interested now in my own hypothesis which I'd dearly like to test.
If I gave you a list of "orographic enhancement days" (moist SW'ly winds),
would you be able to extract the Plymouth rainfall (and wind) data for me?
If we do this well it could end up as a super paper? What do you think?
Could be a lot of work for me initially though to find the days, but that's
science - hard work.

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------
1)Regarding dropbox, I don't think you have to sign up to get the files.
I might be wrong.
You will get a window appearing inviting you to sign up, but if you wait a few seconds the file should appear anyway.

I will email you the file nevertheless Will.

2) Sadly Will, I do not have any wind data for Plymouth.
Historical wind datasets are extremely difficult to get hold of for any station. They are often not hourly measurements, and are of questionable use if not hourly.

The DWRs of course have some wind information up to 1980.

Len
Wembury

--------------------------------------------------------------------------

Len Wood wrote:

On Friday, 30 October 2015 09:17:54 UTC,
One thing about Dartmoor, Graham has pointed out that gale frequency has
dropped right off and it is possible that the decrease in wind speed has
decreased the orographic enhancement (which is where we get a lot of our
rain). So it is perfectly possible for rainfall to decrease or stay the
same on high ground and increase on the coast, especially in winter!
Have winds speeds decreased in Plymouth like Penzance?


Hi Len, again!

Having just read Jim's excellent response and queries in this thread, I'm
getting interested now in my own hypothesis which I'd dearly like to test.
If I gave you a list of "orographic enhancement days" (moist SW'ly winds),
would you be able to extract the Plymouth rainfall (and wind) data for me?
If we do this well it could end up as a super paper? What do you think?
Could be a lot of work for me initially though to find the days, but that's
science - hard work.

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------
1)Regarding dropbox, I don't think you have to sign up to get the files.
I might be wrong.
You will get a window appearing inviting you to sign up, but if you wait a
few seconds the file should appear anyway.

I will email you the file nevertheless Will.

2) Sadly Will, I do not have any wind data for Plymouth.
Historical wind datasets are extremely difficult to get hold of for any
station. They are often not hourly measurements, and are of questionable use
if not hourly.

The DWRs of course have some wind information up to 1980.

Len
Wembury

--------------------------------------------------------------------------

Hourly obs from Mountbatten from Jan 1973 to the present day are available for
free from NCDC. A good starting point is


http://gis.ncdc.noaa.gov/map/viewer/...ourly&layers=1


Unfortunately, there is a bit of a glitch in the NCDC software. The winds in
their database are given in mph, converted from the original knots. From time
to time the software seems to think that the original report is in m/sec so the
mph conversion is spuriously high. Fortunately, the error is sufficiently large
for the spurious obs to be fairly easily identified.

If you need any assistance in getting to the data from the above link let me
know and I'll try to steer you through it.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org

Norman wrote:

Len Wood wrote:

On Friday, 30 October 2015 09:17:54 UTC,
One thing about Dartmoor, Graham has pointed out that gale frequency
has dropped right off and it is possible that the decrease in wind
speed has decreased the orographic enhancement (which is where we get a
lot of our rain). So it is perfectly possible for rainfall to decrease
or stay the same on high ground and increase on the coast, especially
in winter! Have winds speeds decreased in Plymouth like Penzance?


Hi Len, again!

Having just read Jim's excellent response and queries in this thread, I'm
getting interested now in my own hypothesis which I'd dearly like to
test. If I gave you a list of "orographic enhancement days" (moist
SW'ly winds), would you be able to extract the Plymouth rainfall (and
wind) data for me? If we do this well it could end up as a super paper?
What do you think? Could be a lot of work for me initially though to
find the days, but that's science - hard work.

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------
1)Regarding dropbox, I don't think you have to sign up to get the files.
I might be wrong.
You will get a window appearing inviting you to sign up, but if you wait a
few seconds the file should appear anyway.

I will email you the file nevertheless Will.

2) Sadly Will, I do not have any wind data for Plymouth.
Historical wind datasets are extremely difficult to get hold of for any
station. They are often not hourly measurements, and are of questionable use
if not hourly.

The DWRs of course have some wind information up to 1980.

Len
Wembury

--------------------------------------------------------------------------

Hourly obs from Mountbatten from Jan 1973 to the present day are available for
free from NCDC. A good starting point is


http://gis.ncdc.noaa.gov/map/viewer/...ourly&layers=1


Unfortunately, there is a bit of a glitch in the NCDC software. The winds in
their database are given in mph, converted from the original knots. From time
to time the software seems to think that the original report is in m/sec so
the mph conversion is spuriously high. Fortunately, the error is sufficiently
large for the spurious obs to be fairly easily identified.

If you need any assistance in getting to the data from the above link let me
know and I'll try to steer you through it.

I should have mentioned that the obs in the NCDC database are in a decoded
format suitable for import into a spreadsheet.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org

"Norman" wrote in message
...
Len Wood wrote:

On Friday, 30 October 2015 09:17:54 UTC,
One thing about Dartmoor, Graham has pointed out that gale frequency
has
dropped right off and it is possible that the decrease in wind speed
has
decreased the orographic enhancement (which is where we get a lot of
our
rain). So it is perfectly possible for rainfall to decrease or stay
the
same on high ground and increase on the coast, especially in winter!
Have winds speeds decreased in Plymouth like Penzance?


Hi Len, again!

Having just read Jim's excellent response and queries in this thread,
I'm
getting interested now in my own hypothesis which I'd dearly like to
test.
If I gave you a list of "orographic enhancement days" (moist SW'ly
winds),
would you be able to extract the Plymouth rainfall (and wind) data for
me?
If we do this well it could end up as a super paper? What do you think?
Could be a lot of work for me initially though to find the days, but
that's
science - hard work.

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------
1)Regarding dropbox, I don't think you have to sign up to get the files.
I might be wrong.
You will get a window appearing inviting you to sign up, but if you wait
a
few seconds the file should appear anyway.

I will email you the file nevertheless Will.

2) Sadly Will, I do not have any wind data for Plymouth.
Historical wind datasets are extremely difficult to get hold of for
any
station. They are often not hourly measurements, and are of questionable
use
if not hourly.

The DWRs of course have some wind information up to 1980.

Len
Wembury

--------------------------------------------------------------------------

Hourly obs from Mountbatten from Jan 1973 to the present day are available
for
free from NCDC. A good starting point is



http://gis.ncdc.noaa.gov/map/viewer/...ourly&layers=1


Unfortunately, there is a bit of a glitch in the NCDC software. The winds
in
their database are given in mph, converted from the original knots. From
time
to time the software seems to think that the original report is in m/sec
so the
mph conversion is spuriously high. Fortunately, the error is sufficiently
large
for the spurious obs to be fairly easily identified.

If you need any assistance in getting to the data from the above link let
me
know and I'll try to steer you through it.


Thanks Norman, that's brilliant.

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------

On Friday, October 30, 2015 at 9:06:41 AM UTC, wrote:
"Len Wood" wrote in message
...
On Thursday, 29 October 2015 11:25:16 UTC, wrote:
"Len Wood"



Hi Jim,
If you look at the record of annual rainfall for Plymouth 1874 to 2014
you
see how variable it is with no longterm trend, but clearly trends on
the
decadal timescale.

You can see an increasing trend after the drought of the mid seventies,
and then a decrease and now slight increase again.

I have also put in dropbox the link to the graph of summer and winter
rainfall.
There is a significant increasing trend in winter rainfall and a less
convincing decrease in summer rain. Hence no trend in annual rainfall
over
the longterm.

https://www.dropbox.com/s/u0s7p9kroj...02014.jpg?dl=0

https://www.dropbox.com/s/9lfjie7ko4...0rain.jpg?dl=0

If I was you Jim I would hold fire, but if the water usage has gone up
in
recent years and/or the surface morphology has changed then you are
stuck.



Hi Len, interesting stuff, but I have some questions about the graphs?

1. How consistent was the raingauge site over the years.

My experience of looking at Dartmoor gauges has revealed that just a
small
change in location (even a few hundred metres) can make a statistically
sig.
difference to rainfall. Cowsic is a case in question, due to changes in
aspect from one side of a valley to another.

2. In the 19th Century rainguage height was not consistent, in fact a lot
of
gauges were elevated. Scientifically this was proven to produce lower
rainfalls than rainguages on the ground due to turbulence effects.

In my Dartmoor study I have been very careful to only use data where the
raingauge location has been consistent over the decades and where the
height
of the gauge above ground has been consistent. I think that is important.

"Graham Easterling" wrote in message
...
On Friday, October 30, 2015 at 9:06:41 AM UTC,
wrote:
I've linked to this before, but it's still interesting. The lack of gales
over the last couple of decades has changed the fishing calendar. Here's the
coxswain of the Sennen lifeboat trying to get some answers from the MetO on
the subject - and not succeeeding I'd
say!https://www.youtube.com/watch?v=zzCQ...layer_embedded .
==================

Well at least he got a correct honest scientific answer which can be
summarised as "we don't know".

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------

On Friday, 30 October 2015 12:23:15 UTC, Graham Easterling wrote:
On Friday, October 30, 2015 at 9:06:41 AM UTC, wrote:
"Len Wood" wrote in message
...
On Thursday, 29 October 2015 11:25:16 UTC, wrote:
"Len Wood"



Hi Jim,
If you look at the record of annual rainfall for Plymouth 1874 to 2014
you
see how variable it is with no longterm trend, but clearly trends on
the
decadal timescale.

You can see an increasing trend after the drought of the mid seventies,
and then a decrease and now slight increase again.

I have also put in dropbox the link to the graph of summer and winter
rainfall.
There is a significant increasing trend in winter rainfall and a less
convincing decrease in summer rain. Hence no trend in annual rainfall
over
the longterm.

https://www.dropbox.com/s/u0s7p9kroj...02014.jpg?dl=0

https://www.dropbox.com/s/9lfjie7ko4...0rain.jpg?dl=0

If I was you Jim I would hold fire, but if the water usage has gone up
in
recent years and/or the surface morphology has changed then you are
stuck.



Hi Len, interesting stuff, but I have some questions about the graphs?

1. How consistent was the raingauge site over the years.

My experience of looking at Dartmoor gauges has revealed that just a
small
change in location (even a few hundred metres) can make a statistically
sig.
difference to rainfall. Cowsic is a case in question, due to changes in
aspect from one side of a valley to another.

2. In the 19th Century rainguage height was not consistent, in fact a lot
of
gauges were elevated. Scientifically this was proven to produce lower
rainfalls than rainguages on the ground due to turbulence effects.

In my Dartmoor study I have been very careful to only use data where the
raingauge location has been consistent over the decades and where the
height
of the gauge above ground has been consistent. I think that is important.

3. Have you done a statistical Student's T test to measure significance
of
the changes, I suspect that they are very sig (esp. winter). but with the
provisos of my points one and two above.

Jim, you need to look at your local area rainfall over the decades too,
if
you can of course?


You are of course right Will to question the homogeneity of the record.
1874 to 1979 is for Plymouth Hoe Observatory. 36 m asl
1980 to 2014 is for Plymouth Mount Batten. 45 m asl
Mount Batten is about 1.8 km to SE of the Hoe site.

In 1991 I was asked by the Association of British Climatologists (now
defunct) to give a talk at their meeting in Durham on the 'History of
Observatories' about Plymouth Hoe Observatory.
I did a fair amount of research for this, from local libraries, but also a
trip to the Met Archive in Bracknell.
There is an element of vagueness about the early record because there are
never any photos of the site in early times, although the location as a
name remains the same.

2)There was no elevated rain gauge at the Hoe as far as I know.

The dear old Met Office provide the record from 1874 and label it Plymouth
Mount Batten! Mount Batten opened in 1921 when measurements began. The Met
enclosure move up the Mount Batten peninsula in 1940 during WW2.

A comparison of measurements on the Hoe and at Mount Batten shows there is
not a big difference.

https://www.dropbox.com/s/z52svn3b63...red.j pg?dl=0

https://www.dropbox.com/s/2xovemf7r8...tions.doc?dl=0

Will, have you seen my 2004 paper in Weather on Regional trends?

https://www.dropbox.com/s/lx3lrc47c0...0NAOI.pdf?dl=0

I have quite a bit of info on the Plymouth record if you want it.

3)And finally, yes, the increasing trend in winter rainfall is
statistically significant.

Len
Wembury, SW Devon

------------------------------------------------------------------------------

Hi Len, no I haven't seen that paper. Unfortunately I cannot seem to
download from dropbox as it is asking for my account and I don't use
dropbox. Could you e-mail it to me, it looks interesting? Thanks.

One thing about Dartmoor, Graham has pointed out that gale frequency has
dropped right off and it is possible that the decrease in wind speed has
decreased the orographic enhancement (which is where we get a lot of our
rain). So it is perfectly possible for rainfall to decrease or stay the same
on high ground and increase on the coast, especially in winter!
Have winds speeds decreased in Plymouth like Penzance?

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------

I've linked to this before, but it's still interesting. The lack of gales over the last couple of decades has changed the fishing calendar. Here's the coxswain of the Sennen lifeboat trying to get some answers from the MetO on the subject - and not succeeeding I'd say!https://www.youtube.com/watch?v=zzCQ...layer_embedded .

The drop of gales has been significant right up the Atlantic seaboard, as far as Orkney & Shetland.

Of course, there's still the odd year.

Graham
Penzance

Graham,

It seemed to me that the question was "The media are saying we are going to have more extreme weather. Why have we not had more gales?"

The MetO guy avoided saying don't believe everything you hear from the media, especialy the Daily Express. I don't think the MetO have said there would be more gales, only that there would be more extreme events such as heat waves and extreme rainfall events like Boscastle a Cockermouth.

Moreover, we have not seen the full effects of AGW yet. The trend of less gales may suddenly reverse just as quickly as it occurred. We may even see more heat waves - its about time!

On Friday, October 30, 2015 at 11:52:04 AM UTC, Norman wrote:
Norman wrote:

Len Wood wrote:

On Friday, 30 October 2015 09:17:54 UTC,
One thing about Dartmoor, Graham has pointed out that gale frequency
has dropped right off and it is possible that the decrease in wind
speed has decreased the orographic enhancement (which is where we get a
lot of our rain). So it is perfectly possible for rainfall to decrease
or stay the same on high ground and increase on the coast, especially
in winter! Have winds speeds decreased in Plymouth like Penzance?


Hi Len, again!

Having just read Jim's excellent response and queries in this thread, I'm
getting interested now in my own hypothesis which I'd dearly like to
test. If I gave you a list of "orographic enhancement days" (moist
SW'ly winds), would you be able to extract the Plymouth rainfall (and
wind) data for me? If we do this well it could end up as a super paper?
What do you think? Could be a lot of work for me initially though to
find the days, but that's science - hard work.

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------
1)Regarding dropbox, I don't think you have to sign up to get the files.
I might be wrong.
You will get a window appearing inviting you to sign up, but if you wait a
few seconds the file should appear anyway.

I will email you the file nevertheless Will.

2) Sadly Will, I do not have any wind data for Plymouth.
Historical wind datasets are extremely difficult to get hold of for any
station. They are often not hourly measurements, and are of questionable use
if not hourly.

The DWRs of course have some wind information up to 1980.

Len
Wembury

--------------------------------------------------------------------------

Hourly obs from Mountbatten from Jan 1973 to the present day are available for
free from NCDC. A good starting point is


http://gis.ncdc.noaa.gov/map/viewer/...ourly&layers=1


Unfortunately, there is a bit of a glitch in the NCDC software. The winds in
their database are given in mph, converted from the original knots. From time
to time the software seems to think that the original report is in m/sec so
the mph conversion is spuriously high. Fortunately, the error is sufficiently
large for the spurious obs to be fairly easily identified.

If you need any assistance in getting to the data from the above link let me
know and I'll try to steer you through it.

I should have mentioned that the obs in the NCDC database are in a decoded
format suitable for import into a spreadsheet.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org
------------------------------------------------------------------------------
Norman,
I've had trouble with the NCDC database before as it is not quality controlled.
I've cross checked the UKMO Mount Batten precipitation data with NCDC data base and my own obs and found some alarming differences sometimes in the daily data.

Still, it's all we've got as regards wind, so better than nothing.
Shame there is rarely any gust speeds given on NCDC.

Len
Wembury, SW Devon
-----------------------------------------------------------------------------

On Friday, October 30, 2015 at 2:29:08 PM UTC, Alastair wrote:
On Friday, 30 October 2015 12:23:15 UTC, Graham Easterling wrote:
On Friday, October 30, 2015 at 9:06:41 AM UTC, wrote:
"Len Wood" wrote in message
...
On Thursday, 29 October 2015 11:25:16 UTC, wrote:
"Len Wood"



Hi Jim,
If you look at the record of annual rainfall for Plymouth 1874 to 2014
you
see how variable it is with no longterm trend, but clearly trends on
the
decadal timescale.

You can see an increasing trend after the drought of the mid seventies,
and then a decrease and now slight increase again.

I have also put in dropbox the link to the graph of summer and winter
rainfall.
There is a significant increasing trend in winter rainfall and a less
convincing decrease in summer rain. Hence no trend in annual rainfall
over
the longterm.

https://www.dropbox.com/s/u0s7p9kroj...02014.jpg?dl=0

https://www.dropbox.com/s/9lfjie7ko4...0rain.jpg?dl=0

If I was you Jim I would hold fire, but if the water usage has gone up
in
recent years and/or the surface morphology has changed then you are
stuck.



Hi Len, interesting stuff, but I have some questions about the graphs?

1. How consistent was the raingauge site over the years.

My experience of looking at Dartmoor gauges has revealed that just a
small
change in location (even a few hundred metres) can make a statistically
sig.
difference to rainfall. Cowsic is a case in question, due to changes in
aspect from one side of a valley to another.

2. In the 19th Century rainguage height was not consistent, in fact a lot
of
gauges were elevated. Scientifically this was proven to produce lower
rainfalls than rainguages on the ground due to turbulence effects.

In my Dartmoor study I have been very careful to only use data where the
raingauge location has been consistent over the decades and where the
height
of the gauge above ground has been consistent. I think that is important.

3. Have you done a statistical Student's T test to measure significance
of
the changes, I suspect that they are very sig (esp. winter). but with the
provisos of my points one and two above.

Jim, you need to look at your local area rainfall over the decades too,
if
you can of course?


You are of course right Will to question the homogeneity of the record.
1874 to 1979 is for Plymouth Hoe Observatory. 36 m asl
1980 to 2014 is for Plymouth Mount Batten. 45 m asl
Mount Batten is about 1.8 km to SE of the Hoe site.

In 1991 I was asked by the Association of British Climatologists (now
defunct) to give a talk at their meeting in Durham on the 'History of
Observatories' about Plymouth Hoe Observatory.
I did a fair amount of research for this, from local libraries, but also a
trip to the Met Archive in Bracknell.
There is an element of vagueness about the early record because there are
never any photos of the site in early times, although the location as a
name remains the same.

2)There was no elevated rain gauge at the Hoe as far as I know.

The dear old Met Office provide the record from 1874 and label it Plymouth
Mount Batten! Mount Batten opened in 1921 when measurements began. The Met
enclosure move up the Mount Batten peninsula in 1940 during WW2.

A comparison of measurements on the Hoe and at Mount Batten shows there is
not a big difference.

https://www.dropbox.com/s/z52svn3b63...red.j pg?dl=0

https://www.dropbox.com/s/2xovemf7r8...tions.doc?dl=0

Will, have you seen my 2004 paper in Weather on Regional trends?

https://www.dropbox.com/s/lx3lrc47c0...0NAOI.pdf?dl=0

I have quite a bit of info on the Plymouth record if you want it.

3)And finally, yes, the increasing trend in winter rainfall is
statistically significant.

Len
Wembury, SW Devon

------------------------------------------------------------------------------

Hi Len, no I haven't seen that paper. Unfortunately I cannot seem to
download from dropbox as it is asking for my account and I don't use
dropbox. Could you e-mail it to me, it looks interesting? Thanks.

One thing about Dartmoor, Graham has pointed out that gale frequency has
dropped right off and it is possible that the decrease in wind speed has
decreased the orographic enhancement (which is where we get a lot of our
rain). So it is perfectly possible for rainfall to decrease or stay the same
on high ground and increase on the coast, especially in winter!
Have winds speeds decreased in Plymouth like Penzance?

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------

I've linked to this before, but it's still interesting. The lack of gales over the last couple of decades has changed the fishing calendar. Here's the coxswain of the Sennen lifeboat trying to get some answers from the MetO on the subject - and not succeeeding I'd say!https://www.youtube.com/watch?v=zzCQ...layer_embedded .

The drop of gales has been significant right up the Atlantic seaboard, as far as Orkney & Shetland.

Of course, there's still the odd year.

Graham
Penzance

Graham,

It seemed to me that the question was "The media are saying we are going to have more extreme weather. Why have we not had more gales?"

The MetO guy avoided saying don't believe everything you hear from the media, especialy the Daily Express. I don't think the MetO have said there would be more gales, only that there would be more extreme events such as heat waves and extreme rainfall events like Boscastle a Cockermouth.

Moreover, we have not seen the full effects of AGW yet. The trend of less gales may suddenly reverse just as quickly as it occurred. We may even see more heat waves - its about time!

I basically agree with both you & Will. I think we don't yet know what the effects of warming will be on our climate. It's easy to jump to the conclusion that the warming of the poles = reduced temperature gradient (most years) = less gales, but that's only looking at the surface layer.

It's the unknown end result of all the various changes we are making to the worlds ecosystem, from CO2 to land use changes, to water extraction (remember the Aral Sea? http://www.columbia.edu/~tmt2120/introduction.htm ) etc. which is the main reason which should try to minimise our impact on the environment. (End of my Greenpeace bit) I don't share Dawlish's apparent view that the science is settled - anything but.

One thing I would say, is Boscastle has had repeated serious floods ever since the village existed, long before AGW set in. The last flood was nothing particularly special, the water level was just as high twice in the 1950s (I've seen the photos). Far less damage as no big NT car park on the flood plain full of cars to smash into bridges and buildings. Nothing has really changed of course, the all poweful NT won the day, after all exorbitant car park charges largely fund it.

North Cornwall is particularly prone to large rainfall events, due mainly to the sea breeze front, which the geography tends to focus just east of headlands, and the geomorphology.

Graham
Penzance

Len Wood wrote:

On Friday, October 30, 2015 at 11:52:04 AM UTC, Norman wrote:
Norman wrote:

Len Wood wrote:

On Friday, 30 October 2015 09:17:54 UTC,
One thing about Dartmoor, Graham has pointed out that gale frequency
has dropped right off and it is possible that the decrease in wind
speed has decreased the orographic enhancement (which is where we
get a lot of our rain). So it is perfectly possible for rainfall to
decrease or stay the same on high ground and increase on the coast,
especially in winter! Have winds speeds decreased in Plymouth like
Penzance?


Hi Len, again!

Having just read Jim's excellent response and queries in this thread,
I'm getting interested now in my own hypothesis which I'd dearly like
to test. If I gave you a list of "orographic enhancement days"
(moist SW'ly winds), would you be able to extract the Plymouth
rainfall (and wind) data for me? If we do this well it could end up
as a super paper? What do you think? Could be a lot of work for me
initially though to find the days, but that's science - hard work.

Will
--

http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
---------------------------------------------
1)Regarding dropbox, I don't think you have to sign up to get the files.
I might be wrong.
You will get a window appearing inviting you to sign up, but if you
wait a few seconds the file should appear anyway.

I will email you the file nevertheless Will.

2) Sadly Will, I do not have any wind data for Plymouth.
Historical wind datasets are extremely difficult to get hold of for
any station. They are often not hourly measurements, and are of
questionable use if not hourly.

The DWRs of course have some wind information up to 1980.

Len
Wembury

------------------------------------------------------------------------
--

Hourly obs from Mountbatten from Jan 1973 to the present day are
available for free from NCDC. A good starting point is



http://gis.ncdc.noaa.gov/map/viewer/...ourly&layers=1


Unfortunately, there is a bit of a glitch in the NCDC software. The winds
in their database are given in mph, converted from the original knots.
From time to time the software seems to think that the original report is
in m/sec so the mph conversion is spuriously high. Fortunately, the error
is sufficiently large for the spurious obs to be fairly easily identified.

If you need any assistance in getting to the data from the above link let
me know and I'll try to steer you through it.

I should have mentioned that the obs in the NCDC database are in a decoded
format suitable for import into a spreadsheet.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org
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Norman,
I've had trouble with the NCDC database before as it is not quality
controlled. I've cross checked the UKMO Mount Batten precipitation data with
NCDC data base and my own obs and found some alarming differences sometimes
in the daily data.

Still, it's all we've got as regards wind, so better than nothing.
Shame there is rarely any gust speeds given on NCDC.

Len
Wembury, SW Devon
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The original coded observations are available from OGIMET back to 1999.

It's a great pity that NCDC process the data before putting it onto their
database. An archive of the original coded observations would be much better,
even in the old SYNOP code for the older ones. I suppose modern day researchers
would bitch about not being able to understand the code.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org