Monthly Weather Data Report for Cruden Bay Weather Station,
Aberdeenshire - January 2005

Key Measurements and Anomolies Summary
Average Outside Temperature 5.65 °C ( 194.8% )
Minimum Outside Temperature -2.50 °C on the 14th and 18th.
Maximum Outside Temperauture 12.70 °C on the 10th.
Average Outside Humidity 80.42 % ( 99.3% )
Minimum Outside Humidity 57.00 %
Maximum Outside Humidity 94.00 %
Average Wind Speed 3.95 mph ( 32.9% )
Maximum Daily High Wind Speed 34.00 mph
Average Barometric Pressure 1008.20 mb ( 99.9% )
Minimum Barometric Pressure 966.20 mb
Maximum Barometric Pressure 1035.30 mb
Total Monthly Rainfall 45.37 mm ( 55.2% )
Average Bright Sunshine Hours 1.08 hrs/day ( 63.5% )
Total Bright Sunshine Hours 33.35 hrs

A familiar refrain - very dry and very mild. Sunshine hours is a
computed figure from irradiance values and will have suffered a bit
from high building shadow earlier in the month.

More info. on the website under Complete Weather History - Data Archive
if you're so minded.
Regards, John

--
....Cruden Bay, Aberdeenshire
http://www.crudenbayweather.org.uk

In article ,
John Mackenzie writes:
Key Measurements and Anomolies Summary
Average Outside Temperature 5.65 °C ( 194.8% )
snip

Thanks for the stats. What's the 194.8% a percentage of? If you're just
dividing one temperature in degrees Celsius by another (the long-term
mean), then I'd argue that it isn't very meaningful, as by making 0C the
baseline it gives it a spurious significance. It's not like rainfall or
sunshine, where zero really is the lowest value possible.
--
John Hall
"Banking was conceived in iniquity and born in sin"

Sir Josiah Stamp, a former president of the Bank of England

John Hall wrote:

In article ,
John Mackenzie writes:
Key Measurements and Anomolies Summary
Average Outside Temperature 5.65 °C ( 194.8% )
snip

Thanks for the stats. What's the 194.8% a percentage of? If you're
just dividing one temperature in degrees Celsius by another (the
long-term mean), then I'd argue that it isn't very meaningful, as by
making 0C the baseline it gives it a spurious significance. It's not
like rainfall or sunshine, where zero really is the lowest value
possible. --
John Hall
"Banking was conceived in iniquity and born in sin"

Sir Josiah Stamp, a former president of the Bank of
England

Thanks for the advice John. Yes it did look a bit strange and elicited
a sceptical comment from my wife too! The historic mean value for
January that it was based on is 2.9C. I think what you are saying is
that it only makes sense to show the anomoly as the difference, i.e.
2.75C higher?
Regards, John

--
....Cruden Bay, Aberdeenshire
http://www.crudenbayweather.org.uk

John Mackenzie wrote:

Monthly Weather Data Report for Cruden Bay Weather Station,
Aberdeenshire - January 2005

Key Measurements and Anomolies Summary
Average Outside Temperature 5.65 °C ( 194.8% )
Minimum Outside Temperature -2.50 °C on the 14th and 18th.
Maximum Outside Temperauture 12.70 °C on the 10th.
Average Outside Humidity 80.42 % ( 99.3% )
Monthly Weather Data Report for Cruden Bay Weather Station,
Aberdeenshire - January 2005

Key Measurements and Anomolies Summary
Average Outside Temperature 5.65 °C ( +2.75°C )
Minimum Outside Temperature -2.50 °C on the 14th and 18th.
Maximum Outside Temperauture 12.70 °C on the 10th.
Average Outside Humidity 80.42 % ( 99.3% )
Minimum Outside Humidity 57.00 %
Maximum Outside Humidity 94.00 %
Average Wind Speed 3.95 mph ( 32.9% )
Maximum Daily High Wind Speed 34.00 mph
Average Barometric Pressure 1008.20 mb ( 99.9% )
Minimum Barometric Pressure 966.20 mb
Maximum Barometric Pressure 1035.30 mb
Total Monthly Rainfall 45.37 mm ( 55.2% )
Average Bright Sunshine Hours 1.08 hrs/day ( 63.5% )
Total Bright Sunshine Hours 33.35 hrs

A familiar refrain - very dry and very mild. Sunshine hours is a
computed figure from irradiance values and will have suffered a bit
from high building shadow earlier in the month.

More info. on the website under Complete Weather History - Data Archive
if you're so minded.
Regards, John



--
....Cruden Bay, Aberdeenshire
http://www.crudenbayweather.org.uk

John Mackenzie wrote:

Average Outside Humidity 80.42 % ( 99.3% )

John, could you clarify this one too? Does this mean that the 80.42% is
99.3% of the LTA? So the LTA is 80.99%? Is this the usual way of
representing RH anomalies? I find it confusing, and (-0.57) would make
more sense to me. But maybe that's just me.
--
Steve Loft, Wanlockhead, Dumfriesshire. 1417ft ASL
http://www.wanlockhead.org.uk/weather/
Free weather softwa http://cumulus.nybbles.co.uk/
Experimental webcam: http://www.wanlockhead.org.uk/webcam.php

In article ,
John Mackenzie writes:
snip
I think what you are saying is
that it only makes sense to show the anomoly as the difference, i.e.
2.75C higher?

Yes, that's right.
--
John Hall
"If a man will begin with certainties, he shall end in doubts;
but if he will be content to begin with doubts,
he shall end in certainties." Francis Bacon (1561-1626)

Steve Loft wrote:

John Mackenzie wrote:

Average Outside Humidity 80.42 % ( 99.3% )

John, could you clarify this one too? Does this mean that the 80.42%
is 99.3% of the LTA? So the LTA is 80.99%? Is this the usual way of
representing RH anomalies? I find it confusing, and (-0.57) would
make more sense to me. But maybe that's just me. -- Steve Loft,
Wanlockhead, Dumfriesshire. 1417ft ASL
http://www.wanlockhead.org.uk/weather/ Free weather softwa
http://cumulus.nybbles.co.uk/ Experimental webcam:
http://www.wanlockhead.org.uk/webcam.php

Hello Steve. Yes - the historic mean relative humidity figure I am
working from is 81%. I recorded a monthly mean for January of 80.42%.
The relevant summary page on my website does indeed show this as an
anomoly of -0.58 as well as 99.3% (of the LTA). I suppose what you're
saying is that having 2 % figures side by side representing different
things is confusing - and I can see what you mean. I 'll check into
what conventions there are in this area. A quick Google search throws
up an Australian government envoronmental website where anomolies are
represented as % differences from the historic figure, i.e my -0.58
would be represented as -0.72% (from the LTA). I suppose that approach
is less confusing as anomoly % expressed in that way would always be
much lower than relative humidity % figures.

Sorry for the confusion and as a newcomer to these matters happy to
consider any advice. I'll think through the presentation again before
next month!

Regards, John

--
....Cruden Bay, Aberdeenshire
http://www.crudenbayweather.org.uk

John Mackenzie wrote:
Monthly Weather Data Report for Cruden Bay Weather Station,
Aberdeenshire - January 2005

[snip]

.... and a 'hi' to you from just up the road a way.


--
Gianna Stefani

www.buchan-meteo.org.uk

Gianna Stefani wrote:

John Mackenzie wrote:
Monthly Weather Data Report for Cruden Bay Weather Station,
Aberdeenshire - January 2005

[snip]

... and a 'hi' to you from just up the road a way.

Hello to you too Gianni. Like your website - looks very tidy and
accessible - and your data recording looks very rigorous, too.
Regards, John

--
....Cruden Bay, Aberdeenshire
http://www.crudenbayweather.org.uk

"John Mackenzie" wrote in message
...

snip
... the historic mean relative humidity figure I am
working from is 81%. I recorded a monthly mean for January of 80.42%.
The relevant summary page on my website does indeed show this as an
anomoly of -0.58 as well as 99.3% (of the LTA). I suppose what you're
saying is that having 2 % figures side by side representing different
things is confusing - and I can see what you mean. I 'll check into
what conventions there are in this area.

John ... the convention is that for an element which is aggregated
(i.e. has a monthly total) like rainfall or sunshine you express the
variation from normal as a percentage (either an absolute
percentage or difference from normal percentage ... I prefer
the former), while for an element which is meaned (i.e. as a
monthly average) like temperature or RH you express the
variation from normal as the difference between the mean for the
month in question and the long-term mean.

e.g. Mean temperature for Jan 2005: 6.1ºC (+1.9 degC)
Total rainfall for Jan 2005: 60mm (65%)
Total sunshine for Jan 2005: 65hr (118%)

My preference is also to use different units to express an
actual temperature (ºC) and a temperature difference (degC).
This is the Royal Met Soc house-style.

HTH .... Philip Eden