Dublin with a much higher avg rain fall that other areas in Ireland

ivanthehunter

Is there any reason why the rain fall is so high for the Dublin area?

This is a trend at this stage and its becoming an obvious pattern, IMO.

Supercell

ivanthehunter wrote: »

Is there any reason why the rain fall is so high for the Dublin area?

This is a trend at this stage and its becoming an obvious pattern, IMO.

Hope Roisin doesnt see this post!!

Sierra Oscar

What are the rainfall figures?

There is also a sense of . . . if it rains in Dublin and there is flooding the media gets into a frenzy.

There has been flooding outside of Dublin too, sometimes the media seems to forget that.;)

JanuarySnowstor

Sierra Oscar wrote: »

What are the rainfall figures?

There is also a sense of . . . if it rains in Dublin and there is flooding the media gets into a frenzy.

There has been flooding outside of Dublin too, sometimes the media seems to forget that.;)

Couldn't agree more. If Dublin sneezes the rest of the country catches a cold:D

Or is it that we are more hardy down South. Up the rebels

Mobhi1

Why do you say Dublin has much higher rainfall than other areas? Dublin is one of the driest parts of the country on average and if it wasn't for last Saturday's record rainfall it would probably be one of the driest places this summer too.

Deep Easterly

Mobhi1 wrote: »

Why do you say Dublin has much higher rainfall than other areas? Dublin is one of the driest parts of the country on average and if it wasn't for last Saturday's record rainfall it would probably be one of the driest places this summer too.

Have to agree. It was only really one shower that brought Dublin's rainfall figures way above normal. If that shower had missed the station in the airport, and hit somewhere further north with the same amount of rain, there would not be half the talk about it.

Showers of that intensity which hit Dublin Airport and Shannon Airport are quite a regular occurance throughout Ireland in an average summer. It is just that synoptic stations are so far apart around the country that it is rare that one shower like this would hit a station point. One stations figures does not represent the whole area around it in this type of set up.

Mothman

Stats
2008 rainfall to date.
Dublin AP 640mm
Casement 630mm

Rest of Country
Birr 630mm
Ashford Co. Wicklow 670mm
Mullngar 690
Malin Head 770
Claremorris 830
Shannon AP 830
Belmullet 860
Cork AP 880
Valentia 1060

Now if one were to change focus of thread to flooding, then its to do with tarmac and concrete and reducing floodplains, but this is a country wide issue

moe_sizlak

dublin is actually along with kildare the driest county , followed by louth
donegal is the wettest followed by kerry
there are differencing levels of rain in parts of each county , take meath for example , it rains alot more in the northern part of meath beside cavan that it does in hill of down which is beside kinegead

Mullaghteelin

To be fair to the poster, I assume he meant recent rainfall relative to normal. Tonights forecast on RTE showed the rainfall totals relative to normal for the month so far, and by far the highest figures were concentrated along the east coast roughly from Dublin to Dundalk, which of course is normally the driest region of the country.
The primary reason for this is that at this time of year, the heat of the land generates the heaviest convective downpours. Dublin is in one the most sheltered spots in the country when winds are blowing off the land, e.g. from the southwest or west, and hence can be one of the warmest spots. This heat provides extra energy for the type of convective downpours we've seen. The same pattern occured for much of July of last year. This means Dublin can see an unusual (relative to normal) amount of heavy downpours at this time of year in this type of weather pattern.
When this weather pattern occurs in the Autumn or Winter however, Dublin would be one of the driest spots, with the heavier downpours concentrated closer to the Atlantic coasts, beacause by that stage the land is colder and the ocean is the main source of heat.

Mullaghteelin

Just to add to my previous post, the weather pattern we are currently enjoying/enduring is something that is more typical of late autumn or winter. Why we have such weather pattern in August in the first place... well Im not going to attempt to answer that one.

Deep Easterly

moe_sizlak wrote: »

dublin is actually along with kildare the driest county , followed by louth
donegal is the wettest followed by kerry
there are differencing levels of rain in parts of each county , take meath for example , it rains alot more in the northern part of meath beside cavan that it does in hill of down which is beside kinegead

This map of the 61-90 mean rainfall distribution pulled from the Met Eireann website:

RoisinD

Supercell wrote: »

Hope Roisin doesnt see this post!!

I think that what this topic shows is how inadequate the recording system is in Ireland. Anyone who looks daily (or many times a day as I do sometimes) at the rainfall radar on Met Eireann would be well aware of what areas get the most rainfall.

As has been pointed out, the recent weather has highlighted the foolishness of local authorities who have allowed developers to build on the natural flood plains. The amount of rain we have had here over the past few weeks is testament to that. Very little flooding on property as there hasn't been mass development (except for all those holiday home complexes). Rivers have burst their banks but there has been somewhere for the water to go. Some roads have flooded but that is to be expected.
Incidentally while out yesterday we noticed that land around here which is prone to flooding is as bad as we have ever seen it at any time of the year.

How much more rain anywhere can take? We will just have to wait and see:)

ivanthehunter

Mullaghteelin wrote: »

To be fair to the poster, I assume he meant recent rainfall relative to normal. Tonights forecast on RTE showed the rainfall totals relative to normal for the month so far, and by far the highest figures were concentrated along the east coast roughly from Dublin to Dundalk, which of course is normally the driest region of the country.
The primary reason for this is that at this time of year, the heat of the land generates the heaviest convective downpours. Dublin is in one the most sheltered spots in the country when winds are blowing off the land, e.g. from the southwest or west, and hence can be one of the warmest spots. This heat provides extra energy for the type of convective downpours we've seen. The same pattern occured for much of July of last year. This means Dublin can see an unusual (relative to normal) amount of heavy downpours at this time of year in this type of weather pattern.
When this weather pattern occurs in the Autumn or Winter however, Dublin would be one of the driest spots, with the heavier downpours concentrated closer to the Atlantic coasts, beacause by that stage the land is colder and the ocean is the main source of heat.

Thanks Mullaghteelin, that the explanation i was looking for.
Just a note

ivanthehunter wrote:

Is there any reason why the rain fall is so high for the Dublin area?

This is a trend at this stage and its becoming an obvious pattern, IMO.

There is no point showing me charts for avg's to date or for the last year.
The weather is as Mr Mullaghteelin has stated," Dublin can see an unusual (relative to normal) amount of heavy downpours at this time of year in this type of weather pattern"

Also Note
Run off from concrete pavements and asphalt roads is designed in conjunction with main line drainage.
In days gone by all drainage was designed with the understanding that all surface water would be in the pipes with in four minutes, this was know as time of entry in civil engineering terms
Nowadays all modern sites from offices and large housing schemes to small builds of 20 units have to be built with attenuation tanks which retain the rain water which still enters the pipe system with the standard time of entry but the tank only allows the rain water to escape at a certain rate of anything between 5 lt/sec and 15/lt/sec typically. This is to stop main line drainage from exploding under the pressure.
regards Ivan

ivanthehunter

Just to add to the above:
Attenuation tanks mimic the ability of green field lands to retain water and release it slowly.
With the weather that we have being having as of late, all green field would be 100% saturated and in theory they would act similar to concrete or any other impermeable surfaced area.

irish_bob

Deep Easterly wrote: »

This map of the 61-90 mean rainfall distribution pulled from the Met Eireann website:

ok so galway is the wettest , sorry , always thought it was donegal , i would say that east galway is drier than most of donegal though

Deep Easterly

irish_bob wrote: »

ok so galway is the wettest , sorry , always thought it was donegal , i would say that east galway is drier than most of donegal though

I would say that map shows that Donegal and Kerry are wetter counties as a whole. It also gives the impression that the highest rainfall occurs on highground and to the west of highground.

I wonder though how this map like this was put together. How can a mean rainfall distribution map of the entire country be drawn up when rainfall measurements are only taken from just a few stations dotted around, (and even fewer during the 61-90 period). I do have a few figures from around the county of Galway, but many off then were taken only between a 2 and 5 year period in the late 70's. I sure the story is the same around the country. While I think the map above is a good guide, I don't think it tells the full story away from the main synoptic reading areas.

Mothman

Deep Easterly wrote: »

I wonder though how this map like this was put together. How can a mean rainfall distribution map of the entire country be drawn up when rainfall measurements are only taken from just a few stations dotted around, (and even fewer during the 61-90 period).

A few??
More than 700 stations operated during the 61-90 period, many are mountain gauges read monthly.

The 6 wettest are Kerry, then a site in Donegal, all above 300m, one of them 808m! and all above 2800mm/annum

BTW, Dublin Ringsend driest 666mm/annum

Deep Easterly

Mothman wrote: »

A few??
More than 700 stations operated during the 61-90 period.

Mothman wrote:

Dublin Ringsend driest, 666mm per annum

Should that place be renamed "Devil's Ring" or something..? :pac:

Mothman

Mothman wrote: »

A few??
More than 700 stations operated during the 61-90 period,

In case this is misunderstood, they didn't all operate throughtout the full 61-90 period. Many of the Garda Station gauges ceased during the 80s.

Of the c700 gauges, c565 were in operation at beginning of 1961,
Of these 33 closed during 70s, and nearly 200 closed during the 80s, most Garda Stations. Another 154 closed during 90-95 period, again, most of them Garda Stations.
c350 gauges operated for the whole of 61-90 period.

Danno

Is there anywhere online to view this data from individual Garda stations?