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

Snowbie

highdef wrote: »

The anvil above Meath as seen from my balcony in Santry can be seen in the photo section

Yeah have a few shots of it from here with more building right behind it.

squonk

Some decent cumulus to my NW atm but heading NW/N as far as I can see. Nothing sounding or falling anyway!

highdef

Looks like convection is dying down now. I'll pop up the timelapse of the Meath storm tomorrow. Have to head to bed soon as working tonight

CIDK

GFS 12Z run shows good probability for a late night storm in the Munster region. I try not to get my hopes up about these as I'm normally let down.

chris2007

Clouds starting to build up here in North Dublin.

chris2007

Lashing rain here im in the coolock area.

Storm 10

Very wet here tonight but sadly no Thunder all we can do is hope something kicks off.

squonk

Not too hopeful of anything kicking off myself. I had a glimmer earlier in the evening but that went to nothing very quickly. I had a light shower here about 8pm and that's all really. tomorrow looks decidedly wet and, in general crappy

shamwari

Rain & drizzle has started here. It feels cool and a lot less humid than recently. I reckon the shows over now for a while..

Snowbie

The slightest of chances of an embedded rumble or two in the east tomorrow within the rain band.

Some energy in the mix.
Deep wind shear very favourable
Vertical vorticity 700mb with pressure decrease rapidly as air is drawn up quick
500mb RH% indicating some cooler dryer air at altitude. Enough for the odd CB to creep up to a favourable height.

Risk is low but there is one there under all the cloudcover on Wednesday.

TheGreenGiant

thats good news snowbie! thanks for the update

Snowbie

GFS has picked up on a short wave trough following Thursdays heavy rain to swing up through the south and east of the country tomorrow evening and overnight (Thurs/Fri).

As the Jetstream exits the area, lapse rates(instability)will steepen with the air drying out somewhat at height and vorticity advection. This forced advection will trigger the development of CB, and possible storms with the SE highest at risk. However low level shear is minimal but deep directional wind shear is moderate across the SE making any storm moderate to strong.

Will update during Thursday if needed.

Snowbie

The TT (Total Totals) is an index used to assess storm strength. This sometimes does not pick up on some parameters but any index over 51 is classed as severe.

IRISH RAIL

STORMVUE at the moment has a lot of strikes over the east coast anyone awake to verify

Snowbie

00Z has the risk there still and moving more slightly into the south midlands too. Lapse rates are not as high as the attach above but still decent.

maquiladora

Snowbie wrote: »

00Z has the risk there still and moving more slightly into the south midlands too. Lapse rates are not as high as the attach above but still decent.

How would you rate the TS risk for the Waterford area since the 00Z?

Snowbie

maquiladora wrote: »

How would you rate the TS risk for the Waterford area since the 00Z?

Well like the 00z the 06z keeps the risk going. But shear has all but gone so storms shall not be severe. Instability is back on too. So if any sparks are to occur you be first to see them as the unstable conditions are pushing in from the SSW. It's looks to be around 2200-0300 for these. 12Z today should confirm better today the potential as 06z output is still too far away from the event (which is what i based the above on atm)

Snowbie

Last 3 runs maintain the threat of storms for later this evening and overnight. Initially, the threat is for southern areas later moving into the east in the wee hours of Friday morning. Cape values are not impressively high but looking at the satellite the arc at the back of the LP system seems to be developing.

Also to more SE areas, the trough has pepped up the precip and some towers are visible.
The IR sat does not show cloud tops reaching too high atm.

Watch the IR Sat's later to see if CBs build.

http://www.sat24.com/frame.php?html=view&country=gb&sat=vis

darkman2

Snowbie wrote: »

Last 3 runs maintain the threat of storms for later this evening and overnight. Initially, the threat is for southern areas later moving into the east in the wee hours of Friday morning. Cape values are not impressively high but looking at the satellite the arc at the back of the LP system seems to be developing.

Also to more SE areas, the trough has pepped up the precip and some towers are visible.
The IR sat does not show cloud tops reaching too high atm.

Watch the IR Sat's later to see if CBs build.

http://www.sat24.com/frame.php?html=view&country=gb&sat=vis

Im not all that hopeful but would love to see a storm tonight. GFS seems ok but the UKMO is having none of it with just the mid west at slight risk and the rest of the country dry. Will keep an eye on the radar and satellite though.

Snowbie

Compare both GFS model at the same time. The Nw resolution is far more detailed than the US GFS version.
Though the UKMO model does not show the trough.
GFS indicates that a shortwave will develop later this evening to the south steepening lapse rates.

It's a case of which one is right.

maquiladora

Well, all is quiet here in the southeast...it doesn't feel like anything is about to kick off and the loop on Sat24 doesn't look impressive.

Danno

Looks like some cloud development is kicking off high up over Clare on the SAT24. There seems to be quite conflicting wind in Mayo with Knock reporting E Winds, and Claremorris reporting NW. Dew points are between 14 and 15 for most of the country except the SE.

maquiladora

Danno were you adjusting your detector again? :P Looks like a bit of interference on it there now.

Snowbie

Bit of a downgrade on the 18Z alright from some parameters but unfortunately we need most for storms.
Although the Radar shows some moderate echoes over the Celtic sea, recently started to arc NNE and might just clip the SE coast later. Nothing electric in it though.

Danno the centre of the LP is over there or close to atm is why the winds are blowing in different directions.

Snowbie

Dan, in nexstorm go into hardware and raise the noise sensitivity to high to eliminate artificial noise.

Danno

Not doing anything and it is not the bathroom fan. Interesting that it is happening at the same time as the other night?

Pokes

Is your home heating set to operate this time every night.If you have oil heating the the igniters in them can produce up to 10kv ,maybe the detector is picking this up. just a suggestion ?

Snowbie

Dimmer switch and electric fences are known problems. Anything that changes in frequency/resonates slightly in nanoseconds plays havoc with it. The two above are the main cause.

Other sources are TV monitors and games consoles.
Electric cooker and microwave ovens but the antenna would need to be beside these two for interference.

Snowbie

Can see two individual cells over Meath from here with anvils. Must be giving a dump of rain under them. Might get a spark or two out of these.
Showing up nicely on Sat and radar.

http://www.sat24.com/frame.php?html=view&country=gb&sat=vis

Weather BOFH

Snowbie wrote: »

Can see two individual cells over Meath from here with anvils.

I was playing around with the camera earlier and captured these two two the north and north east, I'm guessing it's the storms over Meath.