Thunderstorms

Snowbie

Continue to post here in the event of all things thunderstorm related,wheather it be radar,maps,charts,forecasts or just simple discussions.

Weather pics(clouds,lightning) in attachments only are allowed here otherwise use [thread=2055050139]Weather pics 2007[/thread] for your snaps.

Over the months you will find some variables or terms describing suitability of storms which are:
CAPE - This is the amount of potential energy in the atmosphere. High CAPE will indicate a high chance of thunderstorms.
LI - Lifted Index (LI) displays the 'trigger' potential at the surface to initiate unstable conditions. A low or negative LI will indicate conditions for thunderstorms are favourable.
Cb-Cumulonimbus or thundercloud.
Anvil-Where the top of the Cb reaches the stratosphere and spreads out like a flat top.
Cell or Supercell-An individual storm or a violent storm.
Squall line-Multi cellular organised storms forming in a line usually ahead or parallel to cold fronts.
Embedded Storms-Storms that are contained in overcast conditions
Convection-Warm air rising,cools,condenses forming cumuli clouds.
Orographic lift-Low level winds are forced to rise against rising terrain ie:mountains.Prevailing wind on a hot summers day,this lift can produce rapid convection.
Convergence zone-usually refers to a region in the atmosphere where two prevailing winds meet and interact, usually resulting in turbulent weather.
Lapse rate steepeing-is another fancy term for instability.
Sferics-Sound of low-frequency radio signals that derive from lightning strikes.Common terms would be strikes or strokes.

Some useful links

http://www.irlweather.com

http://www.gyweather.com/

http://www.isleofwightweather.co.uk/live_storm_data_sound.htm

http://www.wetterzentrale.de/pics/Rsfloc.html

Estofex

http://www.blitzortung.org/index.php?mode=0&map=5&lang=e

http://www.nowcast.co.uk/lightning/

http://meteocentre.com/lightning/map_sfuk.php?time=0&lang=en&map=Europe

http://www.estofex.org/guide/

If anyone has any more feel free to post them.

Snowbie

New shiny thread.
If anyone has anymore links(sferics,sats or other detectors etc),feel free to post them up here as i will keep them in OP.

Snowbie

Cape and LI favourable tomorrow for pulse type storms almost anywhere for thursday.At the mo forecast cape here for Dublin in mid 500s j/kg.Not great but a few sparks cant be ruled out.More favourable conditions late afternoon.

ninebeanrows

A number of hefty showers developing this afternoon with thunderstorms over Northwestern and Northern Ireland at the moment.

Some intense echoes on the radar, everything is headed in a west to east direction.;)

fatherdougalmag

God's skateboarding the skies in Citywest.

squonk

Looks like a thunderstorm out here in Clondalkin now. Thought I heard a rumble or two earlier about 5 minutes ago but their was quite a bang just now. It's gone quite dark too.

Weather BOFH

Just had a flash and rumble out here in Citywest!

PauloMN

Intense storm in Glasnevin right now. Crazy heavy rain, thunder and lightning. Never seen the likes.

Snowbie

Yep picking them up on the detector,a couple of flashes here atm.

squonk

Snowbie wrote:

Yep picking them up on the detector,a couple of flashes here atm.

Great detector Snowbie. Works really well and it's very accurate.

v-deniso

Repeated flashes and thunder here in Tallaght

darkman2

Thunder and lightening here atm. Not particularly heavy rain yet.

Mobhi1

Flashes and very loud thunder now near city centre (D8).

one loud rumble of thunder down here in the last few minutes at the tail end of a shower.

rc28

No thunder here yet but some very heavy downpours and then clear blue skies, like April showers...in July

Another couple of short booms.
Quite a distance away this time-possibly in mothmans direction.

sirpsycho

slightly off topic but i see the UK is getting battered sideways with rain and some thunderstorms. nasty looking radar (http://www.metoffice.com/weather/europe/uk/radar/) at the minute.

sirpsycho

Savage detector snowbie! didnt realise you were back up and running.

Pherekydes

A bright flash directly overhead (or so it seemed) at about 3 PM approaching the Kingswood flyover from the Lucan side on my bike, followed by a tremendous crash, followed by a distinct smell of ozone. It seemed bloody close (and bloody stupid) at the time.

rc28

Rumbles of thunder coming from a very impressive looking shower to my west/nw, gonzo in dunshaughlin would have a better view than me.

Snowbie

rc28 wrote:

Rumbles of thunder coming from a very impressive looking shower to my west/nw, gonzo in dunshaughlin would have a better view than me.

Picking them up rc,just exploded into life there with alot of intracloud strikes within a minute.Looks like a good storm.

Supercell

There's a huge CB cloud to the north of me here. Just light drizzle here, looks very dark further north with mamattus on its edges here, artictree, whats it like with you?

Snowbie

There is a massive one here to my west coming over me as i type.

Snowbie

Another rumble of thunder to my SE.

rc28

We had a prolonged downpour with a few more rumbles but not too near. Did anyone see on the news there the massive amount of hail that fell in donegal? The footage showed it built up on the sides of roads but most of it had melted by the time the camera crew arrived. It should be up on their website later so i'll post a link then.

fatherdougalmag

Slow coach wrote:

A bright flash directly overhead ... followed by a tremendous crash, followed by a distinct smell of ozone.

Ah right. Ozone. Yes, I must go for an ozone myself later.



There's a scary cloud to the west of Co. Dublin traveling north. Gas thing is, there isn't a breeze down here at ground level but the lower cloud decks are whizzing along.

Hal1

The sun was shining when I got home and I could see dark clouds in the distance but getting closer they where. 20 minutes or so later the black clouds opened up a really heavy downpour, some rumbles could be heard too. Just as it passed an unmercyfull crack of thunder could be heard and lasted 15 - 20 seconds.

Pherekydes

fatherdougalmag wrote:

Ah right. Ozone. Yes, I must go for an ozone myself later.

Ok, it wasn't the ozone:

The odor from a lightning strike is from ions produced during the rapid chemical changes, not the ozone itself

ninebeanrows

Either theres an earthquake here or the storm to my north is huge

The ground shaking, presume its thunder.. but man that must of been an intense ground strike.

lucernarian

Thunder and some flashes here at about 2.45 pm. I was speaking to someone who was in DCU on the mobile and there was also thunder down there at the time.

Lots of dark walls and cb's around since noon.
There have been a few quick sharp downpours nearby.
In fact theres great structure/artistry to the clouds today.

(I feel so nerdy with this post)

Trogdor

Tristrame wrote:

Lots of dark walls and cb's around since noon.
There have been a few quick sharp downpours nearby.
In fact theres great structure/artistry to the clouds today.

(I feel so nerdy with this post)

Get the camrea out then;)
Not been much around here today

I've actually loads of them in it at this stage and from florida too,if I could find the damn usb cable.
One of the showers came near a few minutes ago and gave a short burst that didnt register.
Another one around 3pm gave a lot of pools just a half mile away but nothing here.

Trogdor

Monday's looking interesting, negative Li values, 400-600 j/kg CAPE and some decent lift. If anything did form there could be localised floods given that the winds are so slack, making the showers very slow moving
http://www.wetterzentrale.de/pics/Rtavn486.png
http://www.wetterzentrale.de/pics/Rtavn4811.png

Tristrame wrote:

If I could find the damn usb cable.

That's not much of an excuse:D

Snowbie

Cape maxing out around the 400j/kg mark which is low enough for storms.Cant rule out the odd rumble today in the heavier showers but cant see anything too significant.

I thought the cape had to be high for storms(500 or higher and preferably above 600) and the LI low ie negative ?

[EDIT] Re reading what you said,your wording is ambigious snowbie-when you are saying "low enough for storms,you mean too low don't you? and not that Cape has to be low for storms which is what I got the first time I read it...and heres me thinking I was going funny in the head:D[/edit]

There might well be thunder in heavy showers today but the conditions going on the usually reliable 6-12 hour GFS more or less rules it out as being a smaller chance.
It's more likely than in Britain though.
It wouldn't be a day for chasing.

Snowbie

To be certain for storms a cape over 600+ desirable and negative 3 LI.
Even with cape at 400,the energy is there albeit low, lift is just negative so there is a small chance.Hilly areas aiding in lift with just enough surface warming could give a local pulse type storm(a few of rumbles) but as i said nothing too significant storm wise.

Cb's are around today though.
Theres one overhead here and it's growing as you look at it-so heavy downpors are imminent.

Snowbie

Tristrame wrote:

Cb's are around today though.
Theres one overhead here and it's growing as you look at it-so heavy downpors are imminent.

With the Nw wind and mountains your in a good location for them showers.Just have to wait and see if they become thundery.Only small cumulus here atm.

Dublin airport is reporting cb's in the last 30 minutes I see.

The wind here is southwest now which aids the progress in my direction of a convection train in the convergence zone from mount leinster northwards-but theres no convergence today (yet),though a southerly might cause it locally.
SW is a good direction for showers in a fast flow though-if it veers south(like it's tending to do at times) It should remain dry here which would be no bad thing to be honest but the associated colder sea air interacting with those cbs inland might cause an sferic or three inland at the interaction points.
The cb's are in the peppering of showers though so there may be a bang or two somewhere later

ninebeanrows

We just had a tremendous downpour here from a seemingly pleasent morning, a speckling of sharp showers countrywise at the moment.

Snowbie

Just back from Howth summit and is a perfect view of land convection and mountain convection going on.I didnt see the sky was blotted with CBs yet but they are building and towering from the NW.

First shower of the day here now.

Trogdor

No rain yet here, but cb's out to sea.
EDIT: just looked out the other window, the one's over the mountains are massive!

Trogdor

Sferics in the North for an hour now, pushing South into Louth
http://meteocentre.com/lightning/map_sfuk.php?time=0&lang=en

Wertz

T-storm out in dundalk bay right now...no flashes but some rumbles, Just after 10 minute heavy downpour....looking good for a hectic afternoon...

SpitfireIV

Very dark, heavy looking clouds to me W, just after having a drawn out rumble of thunder from that direction.

rc28

Two massive downpours here and it's still raining, no thunder yet.

Gonzo

2 big claps of thunder in past 5 minutes:)

Neamhshuntasach

I'm hearing some loud rumbles of thunder outside now up in st. margarets

LoL

I always knew where there are cb's and showers combined,there's likely to be thunder regardless of what GFS says

I can see showers nerby with some belting rainfall out of them.
They are very narrow showers.
I'm expecting rumbles from one or two of them now given what the rest of ye are reporting.

Snowbie

A whole rake of Cbs to my north.Some excellent formations.

Edit:now with a few flashes