Thunderstorm/Convective Watch: Summer 2010

the dinner

Arklows weather forecast for Saturday
http://www.weatheronline.ie/Ireland/Arklow.htm

M.T. Cranium

Have updated forecasts to reflect this excellent discussion and would suggest various other indicators of thunderstorm potential especially with the second of the two cloud masses approaching, timing looks to be about 10 pm to midnight for the first area to arrive west coast, 0100-0300 for the second one, then by 0700 they would be across central Ireland and this gives plenty of time for maximum development later in the day Saturday for the Dublin region and other eastern counties.

Will keep us all busy, I think. If I had to speculate on intensity I would go with 2720G35 and small hail, 15-30 mm rain locally, and frequent lightning being the risks (borderline severe by my standards, but will be quite noteworthy for Dublin if they happen to get that).

By the way, astronomy note for tonight with any clearing to west just after sunset tonight and tomorrow night, would be able to see moon near Venus and should form a very pretty sight. Venus will be occulted by the moon after they both set in my time zone eight hours later, this visible in parts of Asia at about 1300 GMT Saturday.

maquiladora

Looks like an interesting one for the West tonight. D.E. should be in a great position to report on what happens.

Hopefully some good fireworks after dark over there.

Su Campu

Great - Dublin radar's on the blink! :rolleyes: Ah well, as long as Shannon doesn't go too!!!

Deep Easterly

Su Campu wrote: »

Is this that reverse pscychology at work again?? There is upper support with these showers, so we're not relying on surface heating to keep them going inland.

But they are depending on a continuous moist feed from the sea? Upper support, while remaining sufficiently strong as it heads inland, will most likely weaken little at least overnight. But who knows. stranger things have happened.

maquiladora

km79

what direction will that big purple blob be heading hopefully north!!!

Lumi

Deep Easterly wrote: »

But they are depending on a continuous moist feed from the sea? Upper support, while remaining sufficiently strong as it heads inland, will most likely weaken little at least overnight. But who knows. stranger things have happened.

Such pessimism :eek:
I'll take great delight in reporting thunder and lightning from Galway again later:P

Su Campu

Deep Easterly wrote: »

But they are depending on a continuous moist feed from the sea? Upper support, while remaining sufficiently strong as it heads inland, will most likely weaken little at least overnight. But who knows. stranger things have happened.

There's plenty of moisture present to sustain convection given the right upper conditions. The map below shows the average mixing ratio (ie. grams of water vapour per kg of atmosphere) in the lower 1km of the atmosphere, and you can just make out the red streamlines in the west, indication positive moisure advection.



A few hundred J/kg of MLCAPE with equilibrium temperatures around -40°C should give at least some lightning.

Su Campu

Forget tonight - things could be very interesting in the eastern half of the country tomorrow, with everything pointing to frequent thunderstorms, and even a good chance of tornadoes! Surface heating under the deepening upper trough leads to CAPE in the 500-1000J/kg range, with low eq. temperatures and strong windshear meaning frequent heavy thundery showers. The chart below shows the "Significant Tornado Parameter", which takes a lot of these parameters into account and spits out where conditions are conducive for tornadoes to develop.

I'd say ESTOFEX may give a Level 1 in their forecast later.

redsteveireland

That patch over the midlands looks pretty intense.

TheMilkyPirate

Tornados?

I'm only after rebuilding the bird stand in the back and now the bloody things gonna get blown down by a tornado. :pac:

Looking interesting though.

Deep Easterly

So Su , I am to get thunder tonight after all?

Fantastic!

Su Campu

The Met Éireann 00UTC Aviation Chart shows a trough lying SW-NE along the extreme northwest coast, moving eastwards at 15 knots, and another further south, just off the Kerry coast. They give frequent moderate showers and occasional heavy showers and thunderstorms with these troughs, and some isolated areas of 200m visibility in fog over land.

To the southeast the frontal wave is just south of Wexford, giving light to moderate rain and drizzle, and some isolated embedded thunderstorms, though that forecast area covers England and down towards Biscay too.

the dinner

Su Campu wrote: »

The Met Éireann 00UTC Aviation Chart shows a trough lying SW-NE along the extreme northwest coast, moving eastwards at 15 knots, and another further south, just off the Kerry coast. They give frequent moderate showers and occasional heavy showers and thunderstorms with these troughs, and some isolated areas of 200m visibility in fog over land.

To the southeast the frontal wave is just south of Wexford, giving light to moderate rain and drizzle, and some isolated embedded thunderstorms, though that forecast area covers England and down towards Biscay too.

Im starting to feel a little worried.

Su Campu

Deep Easterly wrote: »

So Su , I am to get thunder tonight after all?

Fantastic!

Ssssh, not yet, it's too early for that, keep the reverse psychology going just a little bit longer!!!

Deep Easterly

Fionagus wrote: »

Such pessimism :eek:
I'll take great delight in reporting thunder and lightning from Galway again later:P

Great stuff! Report as soon as possible, so I can hop down there! Want to see if I can capture some night time lightning on cam.

the dinner

24hour precipitation for saturday


This may be wrong and rte has signalled with a few heavy or even perhaps thundery downpours tomarrow but with the showers dying out later in the day.

Lumi

Deep Easterly wrote: »

Great stuff! Report as soon as possible, so I can hop down there! Want to see if I can capture some night time lightning on cam.

No prob! Will make sure the pub has WiFi!!
Later

Su Campu

The area outlined below was that one giving the lightning strikes around 7pm this evening, but since then it has dissipated steadily. We're now relying on something from the comma area ahead of it.....:(

maquiladora

Tomorrow afternoon/evening looks very interesting. Thunderstorms, heavy downpours with a risk of local flash flooding and as Su said even a tornado or two might show up. Maybe worthy of a thread?

the dinner

maquiladora wrote: »

Tomorrow afternoon/evening looks very interesting. Thunderstorms, heavy downpours with a risk of local flash flooding and as Su said even a tornado or two might show up. Maybe worthy of a thread?

Only a few heavy downpours according to rte
and afternoon and evening?

Deep Easterly

Su Campu wrote: »

.:(

That's the spirit Su! :pac:

Edit: I think the best chance of lightning being triggered off from those showers will be as they hit the high ground down along the west coast. Worth keeping an eye out for anyway.

Su Campu

maquiladora wrote: »

Tomorrow afternoon/evening looks very interesting. Thunderstorms, heavy downpours with a risk of local flash flooding and as Su said even a tornado or two might show up. Maybe worthy of a thread?

I've started a thread on it.

Iancar29

NOT FAIR!

IM IN WORK 12-9 2moro!! :mad::mad::mad:

IF ANYTHING STARTS TO HAPPEN IM GOIN OUTSIDE ON A "EXTRA LUNCH BREAK! " :D:D

Su Campu

One strike registered at 22:02 in the Killarney area.

Nearby Kerry Airport reported scattered Cb at 2,500ft at 21:50

Su Campu

Met Éireann's Local Area Forecast for Sligo Airport is giving a slight chance of moderate thunderstorms from 1am - 4am

Deep Easterly

Su Campu wrote: »

Met Éireann's Local Area Forecast for Sligo Airport is giving a slight chance of moderate thunderstorms from 1am - 4am

Any update for Carnmore or Knock?

Oscar Bravo

TAF for Knock
EIKN 101700Z 1018/1118 23008KT 9999 SCT015 BKN035
BECMG 1021/1023 VRB03KT
PROB40
TEMPO 1022/1101 4000 BR BKN005
TEMPO 1101/1109 3000 SHRA BKN005 BKN014CB
PROB30
TEMPO 1101/1108 0400 FG BKN001
BECMG 1106/1109 29012KT
TEMPO 1109/1112 30017KT 4000 SHRA BKN008 BKN017CB

Su Campu

Deep Easterly wrote: »

Any update for Carnmore or Knock?

I'm waiting on their Carnmore and Donegal forecasts. The Knock TAF issued at 17Z below gives only moderate showers, though the next one will be out at midnight, so we'll see what that gives.

EIKN 101700Z 1018/1118 23008KT 9999 SCT015 BKN035 BECMG 1021/1023 VRB03KT PROB40 TEMPO 1022/1101 4000 BR BKN005 TEMPO 1101/1109 3000 SHRA BKN005 BKN014CB PROB30 TEMPO 1101/1108 0400 FG BKN001 BECMG 1106/1109 29012KT TEMPO 1109/1112 30017KT 4000 SHRA BKN008 BKN017CB


Shannon's does give a slight chance of thunderstorms between 2am and 9am

EINN 101700Z 1018/1118 23010KT 9999 SCT015 BKN040 BECMG 1021/1023 16007KT PROB30 TEMPO 1021/1101 BKN012 BECMG 1101/1103 24010KT TEMPO 1101/1109 4000 SHRA BKN008 BKN015CB PROB30 TEMPO 1101/1108 3000 BR TSRA BKN005 BECMG 1107/1109 29014KT TEMPO 1109/1118 30015G25KT SHRA BKN018CB PROB30 TEMPO 1109/1118 5000 BKN012