Convective/Thunderstorm Discussion : Spring/Summer 2017

Oscar Bravo · 01-03-2017 4:41pm #1

Lightning just north of clonmel

JCX BXC · 01-03-2017 4:41pm

Strikes earlier east of Cork City,
A number of recent strikes near Cashel, and one recent strike between Lismore and Fermoy.

When thunder is not in the forecast we get it!

DOCARCH · 01-03-2017 4:43pm

A new thread for a new season.

Meteorite58 · 01-03-2017 6:40pm

Big convection going on all right, some nice Cb's moving inland, charts showing some potential for sferics going into the night.

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Pic : Taken here near Tralee short time ago.

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Clonmel1000 · 01-03-2017 6:46pm

Saw 2 flashes and heard one loud clap of thunder.

Meteorite58 · 03-03-2017 9:50am

Sferic showing up already this morning

Meteorite58 · 04-03-2017 7:33pm

Wonder will we see a squall line cross southern counties in the early morning during the frontal passage, plenty of wind with it and some instability and wind sheer. The SW has potential for thunderstorms tomorrow, mostly offshore if they happen I would think.

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Hal1 · 04-03-2017 10:24pm

VALID 06:00 UTC Sun 05 Mar 2017 - 05:59 UTC Mon 06 Mar 2017

An area of low pressure will cross central Britain through Sunday and unstable air to the south of low could help to trigger some heavy showers and a few thunderstorms, especially across southwest and south central England. There will be decreasing DLS in the wake of the low pressure passing by, however LLS along with coastal convergence could help generate a few funnels or weak tornadoes, especially along the south-central coast of England during the mid to late afternoon.

Source: http://www.convectiveweather.co.uk/forecast.php?date=2017-03-05

Meteorite58 · 18-03-2017 1:14pm

Forecast for wintry showers Mon evening, possibly thundery as well along Western coasts.

Meteorite58 · 20-03-2017 10:29am

Day 1 Convective Outlook
VALID 06:00 UTC Mon 20 Mar 2017 - 05:59 UTC Tue 21 Mar 2017

ISSUED 22:31 UTC Sun 19 Mar 2017

ISSUED BY: Dan

... ENGLAND ...

Strong DLS across the double-structured cold front will likely result in some notable line convection developing as it tracks gradually eastwards, especially from the Midlands / W Country across to E Anglia / SE England. There is a non-zero chance of some embedded lightning with this activity, although the main risks will be a brief spell of very heavy rain and strong gusts of winds. Slight chance of a tornado too.

... WALES, SCOTLAND, REPUBLIC OF IRELAND, NORTHERN IRELAND, N + SW ENGLAND ...
The post-frontal environment will be characterised by ever-steepening lapse rates as cold air aloft overspreads relatively warm SSTs. Showers will become frequent across Scotland, Northern Ireland and the Republic of Ireland on Monday, becoming more widespread into England and Wales on Monday night. A broad LOW has been issued to cater for rather sporadic lightning activity possible with these showers, accompanied by some small hail (and sleet/snow on high ground in particular, but not exclusively so).

Meteorite58 · 20-03-2017 1:08pm

Potential for lightning activity in some Northern areas this evening perhaps .

Oscar Bravo · 20-03-2017 8:43pm

Recent lightning near Achill island

Meteorite58 · 20-03-2017 8:50pm

Just off Wexford also, big showers across the country. Not much activity yet, maybe as the evening goes on.

Dew Points

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downwiththatsor · 20-03-2017 10:27pm

Saw some lightning near Farranfore ten mins ago.

missfarmer · 20-03-2017 10:31pm

Lightning here in North West Cork

Oscar Bravo · 21-03-2017 12:10pm

Plenty of lightning West of Achill now

Storm 10 · 21-03-2017 12:27pm

We had thunder and lightning in Galway in a very heavy hail shower.

Oscar Bravo · 21-03-2017 5:39pm

Plenty of strikes between Enniskillen and Cavan at the moment

Meteorite58 · 27-03-2017 8:20pm

Looks like a chance of lightning tomorrow afternoon / evening .

largethumb.php?date=2017-03-28

Day 2 Convective Outlook
VALID 06:00 UTC Tue 28 Mar 2017 - 05:59 UTC Wed 29 Mar 2017

ISSUED 18:09 UTC Mon 27 Mar 2017

ISSUED BY: Dan

A shortwave trough will migrate NE from Biscay and across the British Isles on Tuesday, accompanied by cool mid-levels and hence steeper lapse rates. Assuming this phases favourably with diurnal heating, several hundred Jkg-1 CAPE will allow scattered showers and a few thunderstorms to develop. However, there is a chance that the upper trough may move through slightly too early for peak heating.

Nonetheless, a SLGT has been introduced where there is some reasonable confidence for an overlap of instability and upper-level support for at least a few scattered thunderstorms to develop, especially during the afternoon/early evening. It is plausible another SLGT may be needed for portions of E Wales and the Midlands into southern parts of N England, but forecast profiles look drier farther east with hints of capping - so while a few showers and/or thunderstorms are also possible here, they are likely to be more isolated / well-scattered in nature, and hence coverage perhaps not high enough to upgrade to SLGT at this stage.

Given instability and dry air aloft, hail up to 1.5cm in diameter is possible in the strongest cells.

27-109UK.GIF?27-12

JCX BXC · 27-03-2017 11:44pm

ME have it mentioned in their forecast also.

Oscar Bravo · 28-03-2017 3:43pm

Recent lightning near Castlerea

Mars Bar · 28-03-2017 4:43pm

Oscar Bravo wrote: »

Recent lightning near Castlerea

The skies were pure black when I left Fairymount so that's not a surprise!

Oscar Bravo · 29-03-2017 3:33pm

Plenty of lightning just east of Enniskillen now. Intense showers also near athlone

Storm 10 · 29-03-2017 3:48pm

Torrential shower in Galway huge raindrops

JCX BXC · 29-03-2017 3:59pm

Lots of convection going on around me here in West Clare

Meteorite58 · 29-03-2017 9:20pm

A few sferics the last couple of days and marginal possibility for a few tomorrow as well but I wonder will Fri see a lot more activity post frontal rain in the afternoon / early evening ?

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sparrowcar · 30-03-2017 11:09am

Any upgrade IYO for today/tomorrow Meteorite58?

Iancar29 · 30-03-2017 1:12pm

06z shows a risk for the NW this evening. Initiating over land then quickly moving out over water. Could still put on a light show for people near the coast.

Decent shear for storms to organise. Could be some nice hail in places before it moves over water.

One worry though would be the cloud moving up from the south which may limit initiation. http://en.sat24.com/HD/en/eu/visual

Oscar Bravo · 30-03-2017 3:43pm

Lightning just north of Sligo town just now

DOCARCH · 30-03-2017 7:03pm

Sferics running up the Irish Sea atm: http://brunnur.vedur.is/athuganir/eldingar/i_dag_na.html?

Meteorite58 · 30-03-2017 8:31pm

Well called Iancar29 , can see the thunderstorm starting over land on the coast of Donegal and moving off shore.

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Meteorite58 · 30-03-2017 8:47pm

sparrowcar wrote: »

Any upgrade IYO for today/tomorrow Meteorite58?

Well plenty of instability tomorrow, but as Convective Weather says will there be too much cloud cover to get convection going. To me showing the most potential for thunderstorms in quite awhile if there is enough break in the clouds.

Convective Outlook
VALID 06:00 UTC Fri 31 Mar 2017 - 05:59 UTC Sat 01 Apr 2017

ISSUED 18:42 UTC Thu 30 Mar 2017

ISSUED BY: Dan

Upper trough approaching from the Atlantic on Friday will serve to steepen lapse rates as cool air aloft overspreads relatively warm SSTs (and diurnally-heated land). The net result is a few hundred Jkg-1 CAPE, with bands of showery precipitation, perhaps isolated thunderstorms, moving N-wards and E-wards across Ireland into western Britain. Some small hail will be possible in the most intense cells.

Better instability will be found over portions of Ireland, but with the proviso that excessive cloudiness may inhibit convective depth somewhat - hence for now have refrained from upgrading to SLGT. A few heavy showers are possible in E England during Friday afternoon, but convective depth looking marginal for lightning. Also, French exports may get close to SE England during the first half of Friday morning and again late afternoon / early evening.

Meteorite58 · 30-03-2017 8:51pm

Met Eireann going for widespread thundery showers in the afternoon after the initall band of rain clears.

Tomorrow

The last of the rain will finally clear northwards early on Friday. Then the day will brighten with good sunny spells in many places for the morning time. However heavy thundery showers will also break out, these becoming widespread through the afternoon and evening. Highest temperatures of 12 to 15 degrees moderate southwest breezes.

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Iancar29 · 31-03-2017 11:07am

Pulse type storms today. Few sferics possible with the better diurnal heating.
Lack of nearby jet streak however given little to no shear so minimal chance for cells to last/organise.

Comhrá · 31-03-2017 12:11pm

Interesting how the streamers are forming over the mountains in W.Cork and moving NE in the airflow. Hopefully a few nice thunderstorms in the Southwest and Midlands in the afternoon.

DOCARCH · 31-03-2017 3:18pm

A couple of sparks now in the Galway and Athlone area: http://brunnur.vedur.is/athuganir/eldingar/i_dag_na.html?

Rikand · 31-03-2017 5:34pm

3 more rumbles over Athlone just now

Rikand · 31-03-2017 5:38pm

The dogs are out in the garden and they're hearing the rumbles of thunder a second or two before we are. They're barking at it before it seems to reach

highdef · 31-03-2017 6:08pm

Rikand wrote: »

The dogs are out in the garden and they're hearing the rumbles of thunder a second or two before we are. They're barking at it before it seems to reach

It must be something else they are barking at. Sound can't arrive at a given location quicker depending on the species of animal hearing it. Maybe some sort of shockwave we can't hear but definitely not the thunder itself

Meteorite58 · 31-03-2017 7:45pm

Lightning activity today, seems to have quietened down now.

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Meteorite58 · 31-03-2017 8:15pm

Again showery conditions developing tomorrow, heaviest in the afternoon, this time coming from the NW. Possibility of some lightning. Perhaps Central, East or South East . Shear low again, doesn't strengthen until early evening and by that time most of the showers should have cleared.

EDIT : Update Only 1 sferic showing up. Just off Rosslare in the afternoon.

pedigree 6 · 31-03-2017 10:10pm

highdef wrote: »

It must be something else they are barking at. Sound can't arrive at a given location quicker depending on the species of animal hearing it. Maybe some sort of shockwave we can't hear but definitely not the thunder itself

It could be the thunder that the dogs are hearing? (I'm definitely leaving the question mark there).
It just could be a higher pitch of sound that travels before the lower pitch that humans can hear.

Dogs can hear a frequency of 67 to 45,000 Hz.
Humans can hear 64 to 23,000 Hz.

As an example say the thunder clap starts off at 40,000 Hz and goes down to 10,000 Hz during the rumble.
Humans wouldn't be able to hear the start of the clap (tune) but dogs would? (Again ?)

Gaoth Laidir · 31-03-2017 10:18pm

pedigree 6 wrote: »

It could be the thunder that the dogs are hearing? (I'm definitely leaving the question mark there).
It just could be a higher pitch of sound that travels before the lower pitch that humans can hear.

Dogs can hear a frequency of 67 to 45,000 Hz.
Humans can hear 64 to 23,000 Hz.

As an example say the thunder clap starts off at 40,000 Hz and goes down to 10,000 Hz during the rumble.
Humans wouldn't be able to hear the start of the clap (tune) but dogs would? (Again ?)

The speed of sound is independent of the frequency so the dogs could not hear it first.

pedigree 6 · 31-03-2017 10:32pm

Gaoth Laidir wrote: »

The speed of sound is independent of the frequency so the dogs could not hear it first.

Maybe I'm not explaining myself properly.
Say someone playing a brass instrument and they start off in a high pitched note and go to a lower pitched note.
What do you hear?
You hear the first note played first.

Actually when you think of it high pitched sound bounces off things while low pitched is absorbed.

Listen I'm not going to argue.
Just offering a hypothesis.

pad199207 · 02-04-2017 11:04pm

Anyone know where you can access the lighting strike count for the US for today? There's have been an incredible amount of lightning activity across the gulf states today!

vicwatson · 02-04-2017 11:08pm

pad199207 wrote: »

Anyone know where you can access the lighting strike count for the US for today? There's have been an incredible amount of lightning activity across the gulf states today!

This any good ?

http://en.blitzortung.org/live_lightning_maps.php?map=30

Iancar29 · 03-04-2017 6:27pm

http://en.sat24.com/HD/en/eu/visual

Some convection taking place in the midlands at present moving NE. The odd sferic is possible id say.

Bsal · 03-04-2017 7:14pm

Looks nice from space

Meteorite58 · 22-04-2017 7:22pm

Monday night / Tuesday chance of Thunder and hail . Met Eireann saying especially in the E on Tues.

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Meteorite58 · 23-04-2017 6:47pm

Day 2 Convective Outlook
VALID 06:00 UTC Mon 24 Apr 2017 - 05:59 UTC Tue 25 Apr 2017

ISSUED 17:37 UTC Sun 23 Apr 2017

ISSUED BY: Dan

On Monday, a sharpening upper trough will slide slowly SE-wards across the British Isles, driving a cold front southwards and eventually introducing an Arctic airmass overnight into Tuesday. Given strong flow aloft along the cold front, some elements of line convection will be possible, albeit in a rather messy fashion and generally lacking in any sufficient depth to be concerned over lightning potential.

However, ahead of the cold front, hints of surface troughing will likely help the development of some low-level convergence on Monday afternoon / early evening, sufficient to generate a few moderately-heavy showers over S/SE England. Overall convective depth is likely to be too shallow for lightning activity, but have issued a low-end LOW threat level to highlight the area with some very marginal potential for isolated lightning activity.

Farther north, more significant instability will develop through the evening and overnight as the upper trough and associated cold airmass drives southwards. During the night hours, the most intense convection will be found over seas and hence affecting windward coasts, and here the lightning potential will be greatest (albeit still considered a LOW threat level in any given location). Small hail and gusty winds will be possible with some of these wintry showers (along with the associated risk of snow accumulations, especially on high ground). A few cold air funnels (or brief tornado/waterspout) will also be possible.

Meteorite58 · 24-04-2017 7:45pm

I wonder will there be a bit of activity along the N and NW coasts later tonight ?

Convective/Thunderstorm Discussion : Spring/Summer 2017

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