Thunderstorms and Convective Potential (Dublin Floods 9/8/08)

Snowbie

MCS still going in the UK more to the East coast but look at that head of canyfloss moving up through France, this has Supercellular characteristic surely, its huge.

http://www.sat24.com/frame.php?html=view&country=eu

TheGreenGiant

indeed its massive and look at the red marks on the rain fall radar.looking very severe indeed over there.there has been loads of them storms brewing up though the past 2 weeks from the south of france moving north.its amazing how fast those types of cells grow!

Snowbie

Estimated at 150' per second.

TheGreenGiant

thats....well, MASSIVE! i noticed there that a storm merged with the main cell on sat24 which certainly increased its severity!

Snowbie

The upper cirrus is already over the channel some distance from the base though.

Deep Easterly

Sierra Oscar wrote: »

Err . . . Met Éireann duty manager had this to say about todays weather:

It is funny, considering a record for most rain to fall in an hour was broken in Shannon.

Source: Irish Times

I think that yer mano was probably mis-quoted by the Irish Times, which is a notoriously Dubcentric spread. Because if it wasn't a mis-quote, it really is a huge "**** you" to the rest of the country.

Storm 10

Deep Easterly wrote: »

I think that yer mano was probably mis-quoted by the Irish Times, which is a notoriously Dubcentric spread. Because if it wasn't a mis-quote, it really is a huge "**** you" to the rest of the country.

Agree with the above quote about Met Eireann, during the 9.30pm forecast he mentioned the heavy rain in the Shannon area and the midlands, there on the radar screen on front of him was torrential rain over Galway, we had Thunder and LIghtning but not a mention.

With respect to our Eastern cousins if this had happened in Dublin we would never hear the end of it, I drove around Galway and there were huge floods.

squonk

Storm 10 wrote: »

Agree with the above quote about Met Eireann, during the 9.30pm forecast he mentioned the heavy rain in the Shannon area and the midlands, there on the radar screen on front of him was torrential rain over Galway, we had Thunder and LIghtning but not a mention.

With respect to our Eastern cousins if this had happened in Dublin we would never hear the end of it, I drove around Galway and there were huge floods.

yeah, but all Gerry said was that there was a record broken in Shannon but the genral gist was that there was pretty heavy rain everywhere. The flooding is more a news item than a weather item per se given that it's already happened.

Looks like Saturday could be a day for a bottle of wine and a DVD!

nacho libre

I think Eagleton would have mentioned both. He is able relate to us lay people and enjoys giving his own anecdotes about the weather. Some of the other forecasters are too robotic.

Damomanye

is Satarday mornings rainfall anything for the flood prone areas around me to be worried about i wonder?

it looks pretty intense on the charts, this far out at least.

TheGreenGiant

yeah I also enjoy Eagleton's weather reports and Evelyn's.

squonk

So do I. Cant' beat the Eagle. He manages to be incredibly informative and I love his style of delivering technical info that he just threw in for background. Excellent!

Managed to get around to looking at some of that Failte Towers last night. Such dross but Evelyn's little segment where she gave her reason for being on the show and why she should stay there was great. After so many shouty, over the top people (I wouldn't call a lot of them celebs), it was really nice to hear someone down to earth and actually almost shy. Met Office 1, Z-Listers: 0.

Mind you I'd leave John Creedon out of the Z category. At least you'd know him, and he was as natural as Evelyn too.

Deep Easterly

Damomanye wrote: »

is Satarday mornings rainfall anything for the flood prone areas around me to be worried about i wonder?

it looks pretty intense on the charts, this far out at least.

It is best to keep an eye on the forecasts up til then Damo. Models at present showing pretty widespread rain alright for Ireland Saturday morning. From what I can see, the Northwest seems to be most at risk for the heaviest stuff, but that could change in the next runs.

Sqounk wrote:

So do I. Cant' beat the Eagle. He manages to be incredibly informative and I love his style of delivering technical info that he just threw in for background. Excellent!

Managed to get around to looking at some of that Failte Towers last night. Such dross but Evelyn's little segment where she gave her reason for being on the show and why she should stay there was great. After so many shouty, over the top people (I wouldn't call a lot of them celebs), it was really nice to hear someone down to earth and actually almost shy. Met Office 1, Z-Listers: 0.

Mind you I'd leave John Creedon out of the Z category. At least you'd know him, and he was as natural as Evelyn too.

Couldn't agree more. I only seen that program once, and once is enough. It is beneath me to watch such pointless rubbish.:D. But come on Evelyn! I hope she wins. A true star of Ireland.

Snowbie wrote:

Originally Posted by Dub Meteorologist
5.3.2: The Mount Merrion Thunderstorm of 11 June 1963 (a 'home-brew' thunderstorm in a south-easterly continental air mass): Reading an old copy of the Irish Times for 11 June 1963 is quite interesting. The main headline refers to the forthcoming visit of President J.F. Kennedy to Ireland, and the possibility that phone lines may be jammed during his visit (due to the FBI taking over the GPO, I presume). This is also some comment on the recent 'Profumo' affair in London. In a small corner on the front page is the day's weather forecast, reading "Another warm and sunny day, but isolated thunderstorms will break out in Munster later" or words to that effect. Not too bad a forecast for 1963....

Of course, later that day many Dubliners experienced their worst storm in living memory, when a violent thunderstorm over the Mount Merrion district deposited 184mm (7.5 inches) of rain in just a few hours, with 3.5 inches of this falling in one hour. It is quite possible that well over 200mm fell in an area where there were no rain gauges, indeed estimates of up to 235mm (9 inches) have been quoted. There was also violent thunder and lightning

Done some research, the highest total from that storm was recorded on high ground South Dublin. 83mm in I hour and 5 mins.

The most recent heaviest fall that I can see occured in Boyle, Co Roscommon, which again recorded 83mm during a severe thunderstorm on the 28th of July 1996. That 83mm fell in 1 hour and 15 minutes.

Just wondering why Shannon's total yesterday is now considered the highest hourly total in Ireland to date?

nacho libre

Deep Easterly wrote: »

It is best to keep an eye on the forecasts up til then Damo. Models at present showing pretty widespread rain alright for Ireland Saturday morning. From what I can see, the Northwest seems to be most at risk for the heaviest stuff, but that could change in the next runs.



Couldn't agree more. I only seen that program once, and once is enough. It is beneath me to watch such pointless rubbish.:D. But come on Evelyn! I hope she wins. A true star of Ireland.

[/I]

Done some research, the highest total from that storm was recorded on high ground South Dublin. 83mm in I hour and 5 mins.

The most recent heaviest fall that I can see occured in Boyle, Co Roscommon, which again recorded 83mm during a severe thunderstorm on the 28th of July 1996. That 83mm fell in 1 hour and 15 minutes.

Just wondering why Shannon's total yesterday is now considered the highest hourly total in Ireland to date?

surely it's just considered the highest recorded at any of Ireland's weather stations

DOCARCH

I believe yesterday's total was being quoted by Met E as the highest hourly total ever recorded at just Shannon (not anywhere else).

squonk

DOCARCH wrote: »

I believe yesterday's total was being quoted by Met E as the highest hourly total ever recorded at just Shannon (not anywhere else).

I'd doubt that. I'd go for the highest recorded total at a ME weather station. He certainly didn't put it across that it was just Shannon, he mentioned anywhere in Ireland.

Deep Easterly

DOCARCH wrote: »

I believe yesterday's total was being quoted by Met E as the highest hourly total ever recorded at just Shannon (not anywhere else).

Met Eireann said that it was the highest hourly total recorded at any of the stations.

Mayo man, you are probably right, the highest recorded at weather stations rather than just rainfall stations (which are still ran by Met Eireann), but they could have mentioned that, as that is just relative, rather than absolute, information.

Mothman

Deep Easterly wrote: »

Met Eireann said that it was the highest hourly total recorded at any of the stations.

Meaning synoptic station, being the only stations until the onset of AWS to take hourly readings.

Rainfall and climatological stations (rainfall and temperature) are read once daily and a timed fall such as at Boyle in 1996 would come about if the observor happened to take note of storm and empty the gauge straight after the event.

I do the same in my station to get data on individual events.

darkman2

Monday looking pretty interesting atm. Subject to change of course but the midlands and east could see thunderstorms on current forcasts.

Danno

wrote:

[url] http://en.wikipedia.org/wiki/Climate_of_Ireland#Rainfall_records [/url]

The greatest hourly total was 97 millimetres; recorded at Orra Beg, County Antrim, August 1980.

So, it's settled, Yesterday's Shannon record is for Shannon only.

Mothman

and that 97mm was in 45 minutes
http://www.torro.org.uk/TORRO/britwxextremes/rainfall.php
http://www.personal.dundee.ac.uk/~taharley/1980_weather.htm
Also http://www.met.ie/climate/rainfall.asp

Mr Benevolent

Monday looking pretty interesting atm. Subject to change of course but the midlands and east could see thunderstorms on current forcasts.

How in hell can the weather be predicted that far in advance? I ask out of curiosity - I'm interested in weather but haven't much of a clue about forecasting.

TheGreenGiant

or more importantly where did you get the forecast? lol

Danno

Looking at the models. Basically, supercomputers churn out a forecast every six hours. These forecasts collectively are known as The Model Outputs!

There are various models that cover our part of the world...
GFS - American
UKMO - British Met Office
ECM - European
JMA - Japanese

A german weather enthusiast website puts the model outputs online about four hours after they are compiled on this site: http://www.wetterzentrale.de/topkarten/fsenseur.html

Each forecast released is regarded as a run. The time of each run is referred in Greenwich Mean Time regardless of the time of year. So, the following terms - 00z, 06z, 12z and 18z refers to Midnight, 6am, Midday and 6pm respectively.

Many characteristics of the weather are covered...
Pressure: http://www.wetterzentrale.de/pics/Rtavn061.png
Mid Level Heat (about 1 mile up in the air) http://www.wetterzentrale.de/pics/Rtavn062.png
Rainfall: http://www.wetterzentrale.de/pics/Rtavn064.png
Ground level temperature: http://www.wetterzentrale.de/pics/Rtavn0617.png (what we feel)
Dew Points: http://www.wetterzentrale.de/pics/Rtavn0610.png
Wind: http://www.wetterzentrale.de/pics/Rtavn068.png

Just a few to get you in to it! Visit the http://www.wetterzentrale.de/topkarten/fsavneur.html website and click around.

TheGreenGiant

great stuff there Danno.thanks a mill! i'm studying weather now this year in college so these sites will come in handy especially in my final year:)

Snowbie

darkman2 wrote: »

Monday looking pretty interesting atm. Subject to change of course but the midlands and east could see thunderstorms on current forcasts.

Confab wrote: »

How in hell can the weather be predicted that far in advance? I ask out of curiosity - I'm interested in weather but haven't much of a clue about forecasting.

TheGreenGiant wrote: »

or more importantly where did you get the forecast? lol

What darkman is saying is that there is a chance of storms on Monday from his interpretation of the models. I checked and he is not far from the truth in posting that but like most of us on here, the general weather enthusiast (nut) community know that the models can chop and change over the next runs.

When i get time i usually post up attach's of a possible event and explain as best i can within 12hrs of it occurring as airmass storms are very hard to pinpoint their location. Thunderstorms are much harder to forecast than snow tbh. There are usually 10 parameters for a Thunderstorm to develop, one or two not there then a TS won't develop.

Any questions which are on topic just post away in relevant threads.:)

Deep Easterly

Danno wrote: »

So, it's settled, Yesterday's Shannon record is for Shannon only.

And so were sown the seeds of doubt...

97mm in 45 mins, not bad. 38mm in one hour, tsk!

As mentioned above, early next week is not without interest:

http://www.wetterzentrale.de/wz/pics/Recm961.gif

Potential for a low to move across Ireland sometime tuesday, preceded by an unstable wsw flow on monday, increasing our chances again of thundery showers breaking out in a slack, variable airflow. Early day's yet though, as positioning of the low seems to be very uncertain once again, with the danger of frontal activity lessening chances. One to watch. (If you're mad):pac:

Takeshi_Kovacs

A few claps of thunder outside just now

M.T. Cranium

Dublin area -- just noticed on meteox radar the possible signature of a severe thunderstorm appearing as of 10 mins ago ... heading ENE

Snowbie

Seems to be some across the midlands too and just west of Dublin.