Irish Weather Statistics

sryanbruen

Artane2002 wrote: »

Nevermind, found it on the MÉ website.

I was planning on giving you a document of all the 2018 data to date on the sunshine hours this weekend. Although, that would take a lot of time going through individual daily data!

Unfortunately, I do not know of any data on snowfall outside of the Snowfall in Ireland PDF they made.

As for the maximum wind gusts, you use the historical database but keep in mind, they're in knots and you would need to convert online to km/h or mph if you wanted to use those measurements instead.

sryanbruen

sryanbruen wrote: »

Daily mean temperatures for Dublin Airport during selected Winters (November to March). Could not include 1955-56 and 1995-96 due to them being leap years.

Look at November/December 2010 standing out against all the rest.....

Wonder how the Summers would look in terms of daily mean temperatures. Any particular stations you guys would like me to take a look at and compare?

Not many stand out in comparison to the Winter periods but mid-July 1983 certainly stands out for Dublin Airport.



Data comes from Met Éireann.

Artane2002

Sryan, have you done a full post on February 1969? I've seen you mentioning it a couple of times but I can't remember if you made a post about it. The northerly back then seemed very potent, bringing -10c uppers right down to Southern England with -15c uppers touching Scotland.

sryanbruen

In November 1988 (30 years ago), cold weather set in due to high pressure bringing dry weather. Huge numbers of people in Dublin were lighting up fires using fossil fuels to heat their homes. This led to pollution and heavy smog was an all-time high for the area. At this time, Dublin was thought to be the most smoke-polluted city (or at least one of the most smoke-polluted cities) as Ireland did not adapt to changes which other countries set including Britain which released the Clean Air Act in 1956 to reduce air pollution in response to the Great Smog of December 1952. This smog was most persistent from the 23rd-26th in localised parts of Dublin although there was several instances of it during the month. The image below was Ballyfermot, Co. Dublin on 24th November 1988.



From an article in 2013 that this was posted in:

This dense mixture of smoke and fog – by its very nature thick, polluting and bad for the lungs – had grown to become a huge issue in Dublin by the late 1980s.

Thanks to bituminous (smoky) coal fires burning in the fair city, the resulting smoke and ashes had added up to become an inescapable problem, particularly on cold and windless nights when the smog became trapped under a blanket of warm air (known as a ‘thermal inversion’).

The problem was so bad that in 1989, Deputy Ruairi Quinn spoke of his frustration at the situation, saying that “We have had promises for the future, we have heard all sorts of promises,” about what the Government would do about smog. He questioned who was benefitting from the sale of the coal, and accused the Minister of State with responsibility for environmental protection, Mary Harney, as being “totally negligent in the execution of her duties”, due to political and personal differences with the Minister for the Environment.

She informed him that they were working towards a 1993 deadline, and that the Government was considering a number of options – and urged people who could afford low-smoke fuels to use them.

This high pressure over top of the country produced severe frosts and freezing fog. Under fog, Clones, Co. Monaghan recorded a maximum of only 1.4c on 25th November 1988 which was well below the average for November at around 9c. Birr, Co. Offaly and Mullingar, Co. Westmeath recorded the lowest minimum temperature of the month of -6.9c on the 21st and 24th respectively. Even Valentia Observatory, Co. Kerry had a minimum of -4.0c on 22nd November, its lowest for November since 1919.

Besides the smog and stubborn fog, November 1988 was a very nice month with well below average rainfall (including only 25% of average November rainfall at Casement Aerodrome, Co. Dublin and 57% of average November rainfall at Valentia Observatory) and sunny conditions (including 144% of average November sunshine at Casement Aerodrome) with the exception of Cork. Maximum temperatures weren't far from average but minimum temperatures were more than 1c below average for stations including Casement Aerodrome and Birr.



RTÉ Archives has a news report on the smog of November 1988.

https://www.rte.ie/archives/2018/1022/1005890-smog-in-dublin/

Data comes from Met Éireann.

sryanbruen

Artane2002 wrote: »

Sryan, have you done a full post on February 1969? I've seen you mentioning it a couple of times but I can't remember if you made a post about it. The northerly back then seemed very potent, bringing -10c uppers right down to Southern England with -15c uppers touching Scotland.

I have not done a post on February 1969 because I was saving it for its 50th anniversary in February 2019.

sryanbruen

Even after all my years of studying weather history or stats, I only realise now that Winter 2009-10 was the joint coldest on record at Dublin Airport with 1962-63. Shocking to say the least as I didn't regard 2009-10 too highly in comparison to previous Winters of the past.



Data comes from Met Éireann.

sryanbruen

Makes sense given the above data!

https://twitter.com/kilkennyweather/status/1067218094643388416

sryanbruen

Just some fun stats for St. Andrew's Day (30 November) in Scotland.

https://twitter.com/metoffice/status/1068522023972827140

Artane2002

Sryan I got a good question for you that you might like to answer when you get back from your holidays (hope you are enjoying it!)

How unusual is it for October/early November to have the coldest weather of the autumn? This year should be one of those years.

mickmackey1

sryanbruen wrote: »

Just some fun stats for St. Andrew's Day (30 November) in Scotland.

https://twitter.com/metoffice/status/1068522023972827140

All quite recent. Seems like Scottish weather is getting more extreme or else their records don't go back very far

sryanbruen

mickmackey1 wrote: »

All quite recent. Seems like Scottish weather is getting more extreme or else their records don't go back very far

The records probably go back to the late 19th century. That 30th November air minimum in 1985 is an all-time record back to the mid-19th century for sure, I know that much.

Artane2002 wrote: »

Sryan I got a good question for you that you might like to answer when you get back from your holidays (hope you are enjoying it!)

How unusual is it for October/early November to have the coldest weather of the autumn? This year should be one of those years.

Thanks, not quite there yet though as I am off to the airport in the morning. Will answer that when I can after I get back too.

Cork Boy 53

Hi sryanbruen, hope you enjoyed your holiday break across the big pond. If you get a chance would you be able to put up some weather stats for December 1989?

Thanks.

sryanbruen

Artane2002 wrote: »

Sryan I got a good question for you that you might like to answer when you get back from your holidays (hope you are enjoying it!)

How unusual is it for October/early November to have the coldest weather of the autumn? This year should be one of those years.

Meant to ask, are you enquiring for an in-depth answer with lots and lots of years of the past as examples, just more recent back to like the 1990s or generally speaking? If it's the former, that will take a lot of time as I'm sure you are aware.

Cork Boy 53 wrote: »

Hi sryanbruen, hope you enjoyed your holiday break across the big pond. If you get a chance would you be able to put up some weather stats for December 1989?

Thanks.

That will be no problem. December 1989 never gets a mention - I can't pretend like I mention it as I don't.

Will be posting some November/December 2010 stats very very shortly as whilst working on my paper on said cold spells behind the scenes for the past month, I have come across some interesting stats that I've calculated.

Artane2002

sryanbruen wrote: »

Meant to ask, are you enquiring for an in-depth answer with lots and lots of years of the past as examples, just more recent back to like the 1990s or generally speaking? If it's the former, that will take a lot of time as I'm sure you are aware.



That will be no problem. December 1989 never gets a mention - I can't pretend like I mention it as I don't.

Will be posting some November/December 2010 stats very very shortly as whilst working on my paper on said cold spells behind the scenes for the past month, I have come across some interesting stats that I've calculated.

If you do have the time to do the former, then that would be interesting but I understand you have other things to do so no pressure

sryanbruen

On the late 2010 stats,

The synoptic station, Mt. Dillon in Co. Roscommon, recorded a total of 208 consecutive hours (which equals to 8.7 days) below freezing from 1400 GMT on the 17th December to 0500 GMT on 26th December. Think about that for a second, 8.7 days (including 8 full days) without touching or going above 0c. In a temperate climate like Ireland's, I think that's incredible. If I had to guesstimate, I would think the only month that could come close to such a stat like this is January 1881. Too bad there weren't many stations then.

This remarkable Mt. Dillon stat is evident on the graph below which shows the hourly temperature observations for selected Irish stations (inc. Mt. Dillon) from 0000 GMT on 23 November to 2300 GMT on 26 December 2010.



Data comes from Met Éireann.

Mount Vesuvius

26/11/10 To 9/12/10
Oak park and Mt.Dillon, 13 consecutive days not above 0°C looking at your graph?

sryanbruen

Well it's the one year anniversary of a memorable day in many enthusiasts' (memorable to me for the wrong reasons!) lives and it would only be appropriate of course for me to do a post on not only the day but the cold spell which began on Thursday, December 7th.

As Storm Caroline pushed eastwards across Scotland on December 7th 2017, the winds became a northwesterly and then a northerly on the western flank of the low. It was a relatively mild day for most as the cold air was sinking southwards from the north with a lot of cloud around at first and some rain. This cleared to sunny spells later with showers turning wintry over Scotland.



These northwesterly to northerly winds became ever more evident on the 8th with widespread wintry showers occurring over the UK and Ireland, most notably over Northern Ireland and the north of Scotland where they were very frequent and as a result, there were accumulations. Nowhere reached 10c with the maximum temperature out of both countries being 9.0c at Mullagh_Carrowlagan, Co. Clare. Over high ground in Scotland and northern England, temperatures failed to get above freezing all day including an observation of -2.0c at South Stainmore, Cumbria. Gale force winds made it feel much colder at times than what the actual temperature suggested. Otherwise, it was a nice bright day with plenty of sunshine.



The northerly flow got cut off on the 9th as the low pressure pushed further eastwards into Scandinavia. As a result, a more flat westerly airstream reached Ireland and the south of the UK which made it a milder day overall though the north was still cold with further wintry showers and icy conditions including a maximum of -0.9c at Malham Tarn, North Yorkshire and an air minimum of -7.3c at Bewcastle, Cumbria in the morning whilst Mullingar, Co. Westmeath had an air minimum of -2.6c. It was another dry, sunny day for the most part but much of Ireland and the southwest of England clouded over during the afternoon. This was as a result of an approaching slider low from the Atlantic which would bring rain at first to the west of Ireland and the southwest of England through the evening.

As the low slid further down Ireland and the UK into the 10th and pushed a bit northeastwards, the rain turned to snow in the cold air. The snow became heavy with significant accumulations recorded over the Midlands of England and some parts of Ireland including an observation of 30cm at Sennybridge, Brecknockshire. Close to coasts, this was mainly cold rain. Scotland recorded further wintry showers and Dalwhinnie in the Highlands had an air minimum of -12.4c early on the 10th, the lowest December temperature in the UK since 2010. Keep in mind, December minimum temperatures haven't been low for a good number of years as the Decembers have tended to be very mild since 2010 for the most part - some have been rather average like 2012 and 2014. Mullingar recorded an air minimum of -3.9c meanwhile. Another ice day over parts of Scotland. More snow occurred over the Midlands of England during the evening.



The slider low cleared on the 11th leaving a bright but cold day across the UK and Ireland although there was some rain in the southeast of England which had pushed up from France during the morning. This would have brought some snow accumulations over the hills. Some wintry showers to the north once again. Dalwhinnie recorded an air minimum of -13.0c whilst Horseleap, Co. Offaly and Casement Aerodrome, Co. Dublin recorded an air minimum of -6.6c. Sennybridge's snow depth was still 31cm at 9am on the 11th. Another very cold morning on the 12th with an air minimum of -13.0c at Shawbury, Shropshire and -3.7c at Horseleap but this cold spell ended there as low pressure approached from the west during the morning.



Data comes from Met Éireann and the UK Met Office.

Here's some pictures.

Choulton, Shropshire. Credit: Jeremy Bolwell:



Wolverhampton on 11 December:



Sally Gap, Co. Wicklow on 10 December. Credit: Skycam Ireland:



Threads on the event.

9/10 December snow-ice warning & slider low ~ https://www.boards.ie/vbulletin/showthread.php?t=2057817783
9/10 December slider low (Technical discussion) ~
https://www.boards.ie/vbulletin/showthread.php?t=2057818137
7/8 December snow-ice warning ~
https://www.boards.ie/vbulletin/showthread.php?t=2057815705
6-7 December Storm Caroline ~
https://www.boards.ie/vbulletin/showthread.php?t=2057816982

sryanbruen

Mount Vesuvius wrote: »

26/11/10 To 9/12/10
Oak park and Mt.Dillon, 13 consecutive days not above 0°C looking at your graph?

Oak Park was above freezing on the 27th and 30th November. It had a run of 66 consecutive hours in between from 1600 GMT on the 27th to 0900 GMT on the 30th below freezing. It had another run of 68 consecutive hours below freezing from 1800 GMT on the 30th to 1300 GMT on the 3rd. It had yet again another run of below freezing temps of 67 consecutive hours from 1800 GMT on the 4th to 1200 GMT on the 7th. Whilst not a very long run of consecutive below freezing temperatures compared to the Mt. Dillon figure during the second cold spell, still remarkable stats nonetheless considering this is Ireland.

Mt. Dillon had similar results.

sryanbruen

https://twitter.com/SnowbieWx/status/1073331111793750016

Cork Boy 53

Hi sryanbruen. Any news on the Dec 1989 stats I requested last weekend? Apologies if you have done this already and I have missed it.

sryanbruen

Cork Boy 53 wrote: »

Hi sryanbruen. Any news on the Dec 1989 stats I requested last weekend? Apologies if you have done this already and I have missed it.

Sorry, I was primarily focusing on Artane2002's request first since it was the more in-depth one of the two but I guess it's no problem that I complete yours before continuing on with that.

sryanbruen

December 2018 has been a wet month for some parts of Ireland particularly the southeast where up to the 13th have recorded more than 80% of their full December monthly average rainfall already. However, even in these places (bar Johnstown Castle), 1st-13th December 2015 was wetter.



Data comes from Met Éireann.

sryanbruen

December 1989 was one of three colder than average Decembers in Ireland during the 1980s for most places although localised parts of the east and southeast had a fairly mild to close to average (but on the mild side) December - the 80s was known for mild Decembers. Compared to December 1981 which had been the coldest December of the 20th century, December 1989 was far less remarkable.

For the CET, it was actually a relatively mild month with a mean temperature of 4.9c. So a bit of a strange month.

December 1989 fell nearly in the middle of an infamous period of mild to very mild Winters following a period of cold/snowy Winters through the mid 1980s (from 1984-85 to 1986-87). It was the only "coldish" month in the period if that makes any sense. It could have been quite a cold month if the pattern wasn't so messy. The 500mb height anomaly reanalysis of the month below shows that the Azores High is displaced with the jet stream attempting to be on a southerly track. However, it gets stopped by high pressure over the med and central Europe which is not good for a cold pattern. The high pressure that was there over Greenland and Iceland tended to be very weak.



In terms of 1951-80 averages, Belmullet had a temperature anomaly of -1.7c below average in December 1989 whilst Dublin Airport and Rosslare had temperature anomalies of +0.5c above average. The mean wind direction during the month was westerly in the south of the country due to the positioning of the jet stream whilst the north tended to have easterly winds which explained the temperature distribution.

The first 10 days of December 1989 were very anticyclonic with plentiful high pressure but this led to frost and persistent fog for some. In urban areas like Dublin similar to November 1988, there was instances of smog. The monthly weather bulletin of December 1989 gives a good account on this smog incident (whilst I did a post on the November 1988 one). Birr got down to -7.0c on 1st December.



The weather turned more unsettled after the first 10 days with low pressure setting up shop to the south and east of Ireland whilst at the same time, an easterly flow developed to the north. These low pressure systems brought a lot of rain to the south of the country including to counties Kerry, Cork and Waterford. Cork Airport recorded 163.0mm (its entire monthly total for December 1989 was 239.0mm) alone between 11th-16th December 1989 including 34.4mm on the 11th, 48.4mm on the 13th and 51.3mm on the 16th. Such large totals in a short period of time of course resulted in severe flooding.

The low that brought the heavy rain on the 16th December was very deep indeed, see the synoptic below for 0000 GMT on 17th December 1989. This storm bottomed out at a pressure of 941mb. Cork Airport bottomed out at 942.5mb, its record low pressure observation since its records began in 1962 and still is to this day.



Another storm on 21st December brought 20-30m waves in the Bay of Biscay and these waves crashed against the La Jument lighthouse in France. The waves smashed through the lower windows of the lighthouse, ripped the front door, flooded the tower and washed away the furniture.



Christmas Eve brought in another deep storm from the Atlantic though thankfully its centre was a distance away from making landfall on Ireland so was not a 16th/17th December scenario. Nevertheless, the winds still blew very hard with the windiest conditions of the month experienced including a 78 knot (144 km/h) gust at Belmullet. It became the mildest day of the month with long fetched southwesterly winds. Dublin Airport had a maximum temperature of 13.7c on the day.



It gradually quietened down for the end of 1989 as a southeasterly airflow developed with the year concluding on a benign note.



December 1989 got crazy wild very fast.

Cork Boy 53

Thanks for that sryanbruen. Yes that is how I remember that month way back then.

Billcarson

Great post on Dec 89. I had forgotten about the frosty spell at the start of the month which was probably the coldest part of that winter. Living in Dublin at the time i remember the smog of early dec 89.

SleetAndSnow

Brilliant post sryan! Since I wasn't born when most of these events happened, I just find them so amazing to read and see what it was like before I actually existed

sryanbruen

The pictures were actually taken in Ottawa, Canada. Unsure as to why the UK Met Office included them in a January 1996 freezing rain case study.

https://twitter.com/snowwatchGB/status/1073928349158912000

sryanbruen

I remember on this day 7 years ago, my school yard was like an ice rink during the morning hours. We did a bit of skating and it was gorgeously cold/sunny. It didn't last long but it was just one of those memorable mornings you can't forget.

Ground temperatures were as low as -8.2c at Casement Aerodrome whilst the air minimum recorded on the day was -4.9c at Mullingar.

Here's the chart for the 16 December 2011.



Don't forget 16 December 2010 was the start of the second cold spell of late 2010 which would become one of the most severe cold spells ever recorded in the history of Ireland.

nacho libre

What a great night it was this time eight years ago. Hopefully we will see something like it in the new year. I hope some records will broken too, so you will have new stats to post about in here Sryan.

sryanbruen

nacho libre wrote: »

What a great night it was this time eight years ago. Hopefully we will see something like it in the new year. I hope some records will broken too, so you will have new stats to post about in here Sryan.

That period was certainly a treat for record breaking.