On The Recording of Official Weather Data

Sponge Bob

Once upon a time the first dedicated Weather Observatory in Ireland was built beside one of them newfangled Telegraph cables. It was Called Valentia Observatory. It still is even though it moved off Valentia a century or more back.

We have had quite a few chops and changes in recent years. Clones is no longer the coldest place in Ireland every winter because the main station is in Ballyhaise to the west. The Galway City Weather station has hopped around the place in the last 30 years and is now in NUIG. Many of these Climatological and Met stations in the past were at Manned Lighthouses and Coastguard stations too before that...but we had no permanent Coastguard after independence did we.?

Once Blacksod Lighthouse was automated Met Eireann has to build a station in Belmullet and observe themselves.

In Fact only Airports and Valentia are manned as in staffed now.

Anyway. The Main Temperature record used on Boards for competitions and squabbles, the IMT, is taken from a 5 station sample selected by the Boards Judging Panel and as per the Monthly Summary. Met Eireann finalises their own definitive IMT some time later once everything is checked and the Gospel is the Monthly Bulletin published some months later.

But records are often set from stations nobody heard of...the record cold in early 2010 was from Mount Juliet and the recor cold in December 2010 from Straidue/Foxford. The record wet in in late 2009 was set in a forestry near Oughterard called Cloosh.

In order to understand this people should know that there are 3 main classes of station.

1. Synoptic Stations. These get mentioned on the news every day and data comes in hourly.
2. Climatological Stations. These can set records but are only checked once a day in the morning.
3. Rainfall Stations. Hi Tech buckets, checked on some schedule I am unaware of, probably.

OH! and

4. Weather Bouys.

The trend in recent years has been to automate and move these synoptic stations to state owned land, Ag Colleges/Ag Research Institutes are a favourite. The Automated stations that report hourly are called a TUCSON...an Acronym invented by Met Eireann I think. The climatological stations are checked manually I believe as are the Rainfall Stations.

Rosslare went to Johnstown Castle. Clones to Ballyhaise, Kilkenny to Oak Park....dammit no more heatwaves Some old stations limped on as Rainfall or Climatological stations thereafter.

The January 2011 Montly Bulletin Has A Very Good Note on the network but leaves out Mace Head which is owned by NUIG even though it is a Synoptic station to all intents and purposes. Sherkin is included because it is no longer owned by UCC ...Met Eireann have a TUCSON there now.

From the 2011 Article. ( last page)

http://www.met.ie/climate/monthlyBulletins/jan11_lores.pdf

Map

Synoptic weather stations are operated by Met Éireann and record all the major meteorological elements on a 24-hour basis. Not all observed elements are available for the synoptic stations at Ballyhaise, Carlow (Oak Park), Gurteen, Mullingar, Johnstown Castle, Malin Head and Roche’s Point, where observations are automated. Climatological stations
are operated by private individuals and observations are made once a day at 0900UTC.


A. General
1. Rainfall amounts are given in millimetres,
temperature in degrees Celsius, sunshine
duration in hours and wind speed in knots.
(1 knot=1.85 km/hour)
2. Climatological stations
make their daily observations at 0900UTC.
At these stations, therefore, a 'day' for the
purposes of this publication refers to the
period from 0900UTC on a particular day to
0900UTC on the following day. Values at
synoptic stations refer to the same period
except where specified.
3. Mean soil and earth temperatures at all
stations are based on readings taken at
0900UTC.
4. ‘Raindays’ and ‘wetdays’ are days during
which the total rainfall is not less than 0.2mm
and 1.0mm respectively. The term rainfall
includes all forms of precipitation, such as
snow and hail, and deposition from dew or
frost, measured as equivalent rain.
5. The mean daily air temperature over a
period is taken as the mean of the daily
maxima and daily minima (averaged separately
over the period).
6. Days with air frost are those during which
the minimum air temperature was below 0°C.
Similarly days with ground frost indicate days
when the grass minimum temperature was
below 0°C. (Grass minimum temperatures are
measured by a thermometer placed
horizontally on pegs just above the tips of short
grass.)
7. A gale is a mean wind over a 10 minute
period of 34 knots or more. A gale gust is a
gust of 34 knots or more. Wind speeds refer to
the wind at an effective height of 10 metres
above the ground, with the exception of Malin
Head, where the height is 18 metres.
8. 'e' denotes that the value is calculated using
one or more estimated readings.
9. Data from Northern Ireland is kindly
provided by the UK Met Office.
B. Agmet
10. Calculated Potential Evapotranspiration
(P.E.) values are based on values of
temperature, sunshine, wind speed and vapour
pressure using the FAO Penman_Monteith
equation. Because of formula limitations,
negative values can occur in winter; these are
replaced in the tables by zero. Measured P.E.
values are those measured by means of soilfilled
tanks sunk into the ground with their
upper grass-covered ends at surface level.
11. Daily Soil Moisture Deficits are based on
moderately drained soils. Soil moisture deficits
and surpluses are computed from the
differences between rainfall, actual
evapotranspiration and drainage. Soil moisture
surpluses are assumed to be removed by
drainage and surface run-off and are therefore
not carried forward from one period to the
next. Soil moisture deficits are regarded as
being cumulative. Where heavy rain occurs
near the end of the fixed period, the date of
cut-off may be adjusted to avoid error due to
insufficient run-off time.
12. Degree day totals are calculated using the
method set out by McVicker in the Journal of
the Institution of Heating and Ventilating
Engineers (Vol. 14 No. 38, Nov-Dec 1946).
13. Global solar radiation values are given in
MJ/sq.m. correct to two decimal places
(3.6MJ=1kWh).
C. Laboratory
14. Daily samples of air and precipitation are
taken at Valentia Observatory at 1000UTC.
15. Air sample data are given in
microgrammes per cubic metre, electrical
conductivity in micro-Siemens p

On the Met Eireann site there is a different map as well as a more detailed explanation of this article ....Here

http://www.met.ie/about/weatherobservingstations/climap.asp

Sponge Bob

Straide Climatological Station in Mayo as Operated by Martin Sweeney.

Here is a piece he wrote on his wettest ever year. 2008. He had operated the station for 46 years at that point. I'll wager he is still there. He certainly was for his record cold in December 2010.

http://www.mayonews.ie/index.php?option=com_content&view=article&id=5751:a-forecast-of-things-to-come&catid=3:news-features&Itemid=29

’08 was the wettest year on record at Straide Climate Station


Martin Sweeney

THE year 2008 was the wettest year on record at Straide Climate Station since I first started monitoring there in 1963. Rain fell on 264 days and the total fall was 1,505.5mm (59.27 inches), making it the wettest year in 45 years. The wettest day was on October 9 when a rainfall of 37.8mm (1.5in) was recorded at Straide.
A feature of the year’s rainfall was the intense falls over short periods. On May 31, a thunderstorm dumped one inch of rain in 30 minutes. This was a rare fall as an inch of rain represents a very wet day’s fall.
During the months of August, September, October and November, there were falls of three to four inches in a week which is more or less a month’s rainfall in seven days. On August 13, four inches of rain fell in 24 hours at the Met Éireann Climate Station in Belderrig on the north Mayo coast.
On July 31, four inches of rainfall was also recorded on the hills south of Newcastle West in County Limerick and a flash flood of six feet from the local river swept everything that was on the main street in Newcastle West. Fortunately, no lives were lost.
During the summer and autumn, there were a few brief high pressure interludes with some pleasant weather. May was a pleasant month with 207 hours of sunshine with the temperatures over 21C on eight days. By May 30, only 13mm of rain had fallen. However, on May 31, 25.5mm fell in a brief thunderstorm.
With ten days remaining in December and with the figure standing at 59.27 inches, it looked odds-on that the 60-inch mark would be surpassed for the first time since I started the station in Straide 45 years ago. However, high pressure became established over the entire region and across Britain with dry cold settled weather and no rain fell from the December 22 to the end of the year.
I have, courtesy of Met Éireann, annual rainfall data from two neighbouring stations within a ten-mile radius and spanning over 100 years. These are from The Rectory in Castlebar (1900 to 1942) and the Ballyvary Garda Station from 1943 to 1962, as well as Straide Climate Station from 1963 to 2008.
All three stations are in more or less flat open countryside with no adjacent mountains to increase the rainfall. However, Castlebar is only a few miles from the Nephin mountain range where there is a high annual rainfall and the annual rainfall for Castlebar is three to four inches higher than in the Straide-Ballyvary area.
Moving back in time in reverse order, I find that during the 45-year period from 2008-1963, Straide has not recorded a 60-inch annual rainfall, the nearest being 59.27 in the year just ended, and the driest over that same period was 34.98inches in 1971. From 1962 back to 1943, Ballyvary did not record a 60-inch rainfall either, the heaviest being 59.81 in 1954 and the driest at 40.31 in 1952.
However, in the timeframe from 1942 back to 1900, Castlebar did record four years in which the rainfall surpassed the 60-inch mark. Those were in 1938 (61.95), 1931 (62.54), 1928 (63.66) and 1903 (60.74). The driest year over the same period as in 1905 (38.19).
Before I close, I return to 2008. The air temperatures ranged from a low of -7.4C on January 6 to a high of 24.7c on July 24. The sunniest day of the year was on May 14 with 13.8 hours. There were three snowfalls in January, February and March with a total depth of 15cm. Thunder was heard on 14 days.

Martin Sweeney has operated the Straide Climate Station for Met Eireann since 1943. Now a retired postman, Martin faithfully chronicles all matters relating to the weather on a daily basis.

Wild Bill

What does this say in relation to any comparisons regarding "climate change" (aka global warming)??

For instance I've noticed that Dublin Airport is consistently colder relative to long term average than Casement (or any of the other main stations).

I've been told this is because the "30-year average" for Dublin Airport refers to a different time period than the 30-year average for Casement!

If the Met Eireann station history in Ireland is reflected across the globe it's no wonder we still have "Global Warming" (sorry..."climate change") skeptics in abundance

Lumi

Unfortunately the Climatological Stations based at NUIG, Straide & Ballygar have either closed recently or are expected to close in the very near future

- just can't get the help anymore

Sponge Bob

Lumi wrote: »

Unfortunately the Climatological Stations based at NUIG, Straide & Ballygar have either closed recently or are expected to close in the very near future

- just can't get the help anymore

Well they could if they settled on a combined automatic / manual system...maybe one that required manual checking to double confirm extremes and appealed to some of the wonks in here or on Irelands Weather to host them.

Mothman

Sponge Bob wrote: »

We have had quite a few chops and changes in recent years. Clones is no longer the coldest place in Ireland every winter because the main station is in Ballyhaise to the west.

Unfortunately the changes at the likes of Clones, Rosslare, Birr and Kilkenny were enforced because of encroachment from development on neighbouring sites. This compromised the environment within the station grounds and meant the exposure was not consistent from earlier in the station's history. I do blame the local planners in not providing a green buffer zone around each station.

In Fact only Airports and Valentia are manned as in staffed now.

And Belmullet though I think it will go the way of Malin Head etc.

In order to understand this people should know that there are 3 main classes of station.

1. Synoptic Stations. These get mentioned on the news every day and data comes in hourly.
2. Climatological Stations. These can set records but are only checked once a day in the morning.
3. Rainfall Stations. Hi Tech buckets, checked on some schedule I am unaware of, probably.

I don't think classes is an appropriate term. The synoptic stations and climatological stations have the same standards with regard to temperature recording. Just how they go about it is different. The standards being the accuracy of the equipment and the exposure of the sites

All synoptic and climate stations measure rainfall as well. In addition there are 100s of rain gauges. These are standard 5" copper gauges, most of which are read once a day. In the mountains or perhaps other remote areas, gauges are emptied once a month. Climates stations use the same rain gauges.

The trend in recent years has been to automate and move these synoptic stations to state owned land, Ag Colleges/Ag Research Institutes are a favourite. The Automated stations that report hourly are called a TUCSON...an Acronym invented by Met Eireann I think. The climatological stations are checked manually I believe as are the Rainfall Stations.

TUCSON = The Unified Climate and Synoptic Observation Network
I run a climate station. See Ashford in the map above. The readings are done at 0900gmt every day, 365/6 days of year. (I change suncard between dusk and dawn) The instruments are all manual instruments, mercury or alcohol thermometers, copper rain gauges (although the newest ones are swanky stainless steel ) and Campbell Stokes sun recorder. The air max/min thermometers are housed in a Stevenson screen. (white louvered box on legs)

Rosslare went to Johnstown Castle. Clones to Ballyhaise, Kilkenny to Oak Park....dammit no more heatwaves Some old stations limped on as Rainfall or Climatological stations thereafter.

See earlier about why Rosslare, Clones, Birr and Kilkenny closed. Recording has continued by a volunteer in Kilkenny on a different site, i think about 1km from the previous site. Recording at Johnstown Castle commenced in 1966 (rainfall 1914), Oak Park also the 60s but I think there was a break in the 70s, so not a continuous record. Ballyhaise is more recent and I don't think Gurteen (to which synoptic station moved to from Birr) had any climatological record before 2008.

The January 2011 Montly Bulletin Has A Very Good Note on the network

This is in every January Bulletin.

Sherkin is included because it is no longer owned by UCC ...Met Eireann have a TUCSON there now.

Sherkin has been in the bulletin for 30 years

Wild Bill wrote: »

What does this say in relation to any comparisons regarding "climate change" (aka global warming)??

For instance I've noticed that Dublin Airport is consistently colder relative to long term average than Casement (or any of the other main stations).

I've been told this is because the "30-year average" for Dublin Airport refers to a different time period than the 30-year average for Casement!

If the Met Eireann station history in Ireland is reflected across the globe it's no wonder we still have "Global Warming" (sorry..."climate change") skeptics in abundance

The weather station site at Dublin AP has been moved twice. Once in 1994 and more recently in the latter of the 2000s. Read this thread for more detail

Sponge Bob wrote: »

Well they could if they settled on a combined automatic / manual system...maybe one that required manual checking to double confirm extremes and appealed to some of the wonks in here or on Irelands Weather to host them.

Met Eireann are always on the look out for sites and observers. But it is a very tall order to find a site that has a good exposure, that will remain consistent, is secure (vandalism is a huge issue) and has observers to do readings at 0900gmt every day without fail.
I contacted Met E in the 90s about being an observer but i could not commit to the 10am readings in the summer. Eventually I was able to and a rain gauge was installed in 2001. Once they saw that was reliable they installed a Stevenson screen in 2002. My main motivation for doing this was to have ongoing means to calibrate my own AWS. For example I recently had to adjust my AWS by O.6C It suddenly shifted. How would I know this without the backup. I could blissfully be recording 0.6C too high for years....

Sponge Bob

Mothman wrote: »

.
I contacted Met E in the 90s about being an observer but i could not commit to the 10am readings in the summer. Eventually I was able to and a rain gauge was installed in 2001. Once they saw that was reliable they installed a Stevenson screen in 2002.

I was pointing out that a regime that requires one to be onsite every single day may no longer be feasible and that attendance onsite should be occasional/periodic rather than mandatory.

Mothman

Sponge Bob wrote: »

I was pointing out that a regime that requires one to be onsite every single day may no longer be feasible and that attendance onsite should be occasional/periodic rather than mandatory.

The infrastructure required for this, which is an automatic station is huge. At least with a current climatological station, should the land owners/observers circumstances change the equipment can be removed in an hour or 2. Not so with an automatic station.

TUCSON station cost c.100k

But yes, technology now does make it feasible do as you suggest. Suitability and security of site remains coupled with the requirement of long term lease of say 30 years

Sponge Bob

Mothman wrote: »

TUCSON station cost c.100k But yes, technology now does make it feasible do as you suggest. Suitability and security of site remains coupled with the requirement of long term lease of say 30 years

I am not proposing a Tucson but a much less sophisticated, cheaper and limited variant and with periodic manual intervention and double checking.

If the number of visits changed rom once daily at precisely 9 (or 10 in summer) to say 2 or 3 visits and at more convenient times it may help. Not for me to decide though.

Time was when a man was stuck on a rock for weeks on end and needed the distraction but the only permamanned complex on the entire coast is now the Valentia Coastguard and maybe a Navy Ops room in Haulbowline...but more likely in Dublin.

Funny how Valentia has 2 x 24 hour assets when the rest of the country has none!

Sponge Bob

The climatological stations are not part of any 'Global' record. Only Synoptics qualify. Fairly Much a Non Issue. Climatologicals change quie a bit over time as people retire or find other things to do.

None of the Synoptic time series in Ireland are in question bar maybe some squabbling we did in a thread over the Phoenix Park station which was a synoptic once I think but which is long replaced by the 2 Dublin airport stations. Arguably this is counterbalanced by another thread which asserts with some foundation that there is a cold bias at Dublin Airport. The only other synoptic station that change substantially may have been Rosslare or was that Carnsore to Johnstown Castle. Net result is negligible.

Both of those squabbles are inconclusive rather than impure.