Severe thunderstorms over parts of Ireland August 31 2005, a modified spanish plume setup?

Stundon93

Hello all. So I was curious if anyone on here remembers, all be it a long time ago now, the severe thunderstorms that moved through Ireland on August 31 2005? Given the fact that severe thunderstorms are relatively rare events in Ireland, I am a little surprised that not many people seem to remember this one. I am not a meteorologist, but I have read about the july 25-26 1985 thunderstorms, which appears to have been a mesoscale convective system that crossed Ireland, and the August 11 1997 mcs that moved through Dublin, but I could find very little on August 31 2005. It is easily one of the most memorable thunderstorms I have ever experienced in Limerick. I remember the day very well, it was a very hot and sultry day, and I later found out one of the hottest days of that summer!! The convective setup was very interesting, and , I might add, I have rarely seen a setup like this for Ireland, especially so late into August!! According to the few reports of this event I have been able to find , a low pressure system moved north from Bay of Biscay to southeast Ireland. The Low was still in it’s deepening stage as it was moving up from Biscay. A strong cold front moved across Ireland and western scotland, with strong qg forcing ahead of it and strong windshear. The convective forecast called for a risk of mesoscale convective systems, bow echos and even supercell thunderstorms! The storms in Limerick that day were quite long-lived, and easily lasted most of the afternoon, some of the loudest thunder I ever heard in Limerick, and I was a young child when that happened. It appears that the atmosphere was too capped over England for much of the day tu support much in the way of convection. It seems that many severe thunderstorm setups in Ireland are an extension of the Spanish plume setups that sometimes effect the UK. I am new to the furm and am unable to post links for the moment but estofex issued a very interesting convective forecast for that day.

highdef

I would've been living in Dublin at that time. There were some fantastic plume type thunderstorms right through the weekend of mid August last year in parts of the Midlands. Would the storms you're talking about have been similar in intensity to what you're talking about?

https://youtu.be/Mpz7oCXh1Vo

Stundon93

So sorry for my late reply, I never got the notifications through my email about the comments. Yes they would have been somewhat similar, but the storms of August 31 were much louder, the windows were ratteling, something which I had rarely experienced here. Not sure if Dublin got in on the action that day but it was very bad in Limerick on that day. Not sure if any archived forecasts exist of those storms. Estofex forecast was the most interesting. They had forecast mesoscale convective systems, bow echos and even supercells. I think they were more similar to the June 28 2012 setup.

Gaoth Laidir

Here's the ESTOFEX forecast for that day. Focus was more on Eastern Ireland.

https://www.estofex.org/forecasts/outlook/html/200508311030cf.html

CONVECTIVE FORECAST

VALID Wed 31 Aug 10:00 - Thu 01 Aug 06:00 2005 (UTC)

ISSUED: 31 Aug 10:30 (UTC)

FORECASTER: GATZEN

There is a slight risk of severe thunderstorms forecast across Great Britain and eastern Ireland

There is a slight risk of severe thunderstorms forecast across western France, northern Iberian Peninsula, western North Sea region

SYNOPSIS

Intense long-wave trough present over northeastern Altantic Ocean slowly propagates eastward. At its base ... well-developed short-wave trough/vort-max travels northeastward crossing most of western Europe during the forecast period. Associated strong jet streak travels from western Portugal to Scotland on Tuesday. To the east ... high pressure system over central Europe ridges into Scandinavia. Over central Mediterranean ... upper cut-off low propagates eastward.

DISCUSSION

...Great Britain and eastern Ireland ...

Focus of severe convective activity is expected over Great Britain. Plume of high THETA-E originating from Iberian Peninsula now located over Bay of Biscay region is forecast to spread northward into British Isles during the next hours. Latest soundings show rich low-level moisture and quite warm/stable airmass aloft ... and strong instability was not measured. Thunderstorms have developed from northern Bay of Biscay to western channel region, though ... indicating that CAPE is already present. During the day ... strong upper jet streak travels northward over western Great Britain/eastern Ireland ... and quite strong QG forcing is expected underneath the right entry region of this jet streak. At the surface ... models show deepening low pressure system moving from northern Bay of Biscay to southeastern Ireland. A surface cold front is expected from western France to western Great Britain on Tuesday, 15 UTC. Thunderstorms are forecast to develop along this cold front/convergence during the next hours and should spread NNEward over Great Britain. Strong deep layer wind shear is forecast in the range of the upper jet streak ... and thunderstorms should likely organize into multicells, bow echoes, and supercells ... capable of producing severe wind gusts, large hail, and intense precipitation. Increasing low-level vertical wind shear due to falling surface pressure over northern France/The Channel region and low-level bouyancy due to insolation ... seems to be also favorable for tornadoes. Amount of low-level instability is unclear ATTM ... given quite strong inversion indicated by latest soundings over western France. Especially over southern Great Britain ... low-level airmass is expected to be capped during the day ... and chance for organized thunderstorms is limited. However ... allover threat seems to be quite high today ... and an upgrade to MDT may be warrant. Later in the period ... persisting QG forcing/WAA advection is forecast ... and thunderstorms are expected to merge into a sqall-line/MCS moving northeastward into western North Sea. Severe wind gusts and flash flooding should be the most significant threat. Isolated large hail and tornadoes are not ruled out, though.

...Bay of Biscay, France, northern Iberian Peninsula, Benelux ...

East of a cold front that propagates eastward over France and Iberian Peninsula ... WAA is expected from northern Iberian Peninsula to western North Sea region during the period. Associated warm aimass is characterized by quite rich low level moisture ... and models show instability due to insolation during the day. Along the cold front ... thunderstorms are expected as upper vort-max/short-wave trough travels northeastward. Vertical wind shear is forecast to be in the range of 15-20 m/s ... and mesocyclones and multicells may form ... capable of producing large hail, severe wind gusts and intense precipitation. Allover threat seems to be quite low.

bancoder

Thanks for your sharing, I will visit more often

stooge

August 31st 2005 Thunderstorms — boards.ie - Now Ye're Talkin'

good few pots on the thread above. as you say, Limerick seems to have had some loud thunder.

highdef

https://www.boards.ie/discussion/comment/120611526#Comment_120611526

It was fascinating to read back on that old thread. Fascinating because everybody spelled "lightning" correctly! Not one mention of "lightening" 😊

Stundon93

So this was a Spanish Plume event by the sound of things then. I wonder which part of the country got the worst storms that day? Certainly Limerick had very loud thunder and torrential rain. I wonder if this was a similar setup synoptically to the july 1985 event. Now, the storms on August 31 were nowhere near on the scale of the July 25 1985 setup, but the synoptic setup was interesting for me. I vividly recall that the forecast from rte and met eireann that day was for only thundery showers, but it turned out to be much more than that.