Convective/Thunderstorm Discussion: Spring/Summer 15

Iancar29

For anyone having thunderstorm withdrawal symptoms , my video from last week in South Dakota may help

https://www.youtube.com/watch?v=xI629qTUAK8

maquiladora

Thunderstorm near the Channel Islands at the moment.

http://www.meteociel.fr/observations-meteo/foudre-direct.php?region=uk


Could see this activity continue to develop over southwest England/Wales/Irish Sea through the night and into early tomorrow morning. If that happens, there is a slim chance something makes it as far as the east coast here.

jimmynokia

Iancar29 wrote: »

For anyone having thunderstorm withdrawal symptoms , my video from last week in South Dakota may help

https://www.youtube.com/watch?v=xI629qTUAK8

Why cant we have stuff like that here :mad::mad:

Oneiric 3

Not sure where the EURO4 is coming from but showing prep totals over parts of the west up to and over 20 mm over the course of tomorrow? It must be seeing more 'oomph' in that Atlantic front than the other hi-res models.

jimmynokia

Weather report on RTE was pretty boring

Rikand

Could that "oomph" mean thunder for those of us in the whest?

Oneiric 3

Rikand wrote: »

Could that "oomph" mean thunder for those of us in the whest?

I would doubt it* Think thundery showers would more likely develop further east towards the midlands &east away from the main frontal band.



*but secretly hopes

maquiladora

Hot off the presses. The east coast catches the edge of a Level 1. :P Northern England looking like being the place to be though....

DISCUSSION

... England, Scotland ...

Potentially very severe situation with number of question marks will develop over parts of UK. As the plume of steep lapse rates overspreads the low level airmass characterised by dewpoints of 16 - 18 deg C, moderate degree of latent instability will develop over the region. CAPE values will stay mostly between 500 - 1500 J/kg, but some models allow up to 2000 J/kg of CAPE, especially over N England / S Scotland. Strong flow at low to mid-troposphere will result in 15 - 25 m/s of 0-3 and 0-6 km bulk wind shear, values well conducive for organised convection. Furthermore, veering of wind with height will favour curved hodographs and more than 200 m2/s2 of SREH in the 0-3 km layer. Such conditions would be very conducive for supercells, probably in the HP mode, or bow echoes, as much of the wind shear is confined to the surface to 700 hPa layer. Large (or even very large hail), damaging winds and even tornadoes (especially in the northern part of Lvl 2 with low LCLs) could accompany such well organised storms.

There are two factor that may limit the overall severity of the situation:
A/ Degree of initiation. With no strong synoptic-scale upward motion and in the capped airmass, it may be difficult to initiate storms. Initiation will be more likely in the evening hours as 850 and 700 hPa temperatures begin to drop from the west and cold front affects the area.
B/ Stable boundary layer. Due to the very hot airmass around 850 hPa, it will require a lot of heating to destabilise the boundary layer and allow storms to root in it. Thus, especially in the early period, most storms will stay elevated (with primarily hail threat), as they move from France towards England. Surface based development will be most likely in the late afternoon and early evening hours.

Level 2 is introduced for the area, where best CAPE/shear overlap is simulated, as well as with the best chances for the surface based storm initiation.

FWVT

Just flown home from Luton and there were some nice Cbs over SW England alright

maquiladora

Oneiric 3 wrote: »

Not sure where the EURO4 is coming from but showing prep totals over parts of the west up to and over 20 mm over the course of tomorrow? It must be seeing more 'oomph' in that Atlantic front than the other hi-res models.

Hooter23

They mentioned torrential rain in the west of ireland also on Sky News weather...

Iancar29

maquiladora wrote: »

Hooter23 wrote: »

They mentioned torrential rain in the west of ireland also on Sky News weather...

Non convective stuff ... aka messy

maquiladora

Iancar29 wrote: »

Non convective stuff ... aka messy

Yeah some of it is frontal but there could be some convective stuff mixed in too. Probably nothing significant though....

Danno

Looking south on the IR animation and there appears to be a band forming between the cell off W France and the cold front. This could develop and hit us tomorrow?

Iancar29

maquiladora wrote: »

Yeah some of it is frontal but there could be some convective stuff mixed in too. Probably nothing significant though....

Latest WRF has some hope for the east within some modest instability tomorrow evening. Also in line with estofex's thoughts for a late cap break for N.England and Scotland

maquiladora

WheatenBriar

Some showers heading towards wexford no sparks
I can see them from Arklow
Fair warm in the cloud 21c
Breeze coming from direction of showers

Wanderer78

maquiladora wrote: »

what app you using?

maquiladora

Wanderer78 wrote: »

what app you using?

http://www.sat24.com/en/gb

Some cells getting a bit closer to the southeast coast now.

WheatenBriar

Raining here near Arklow at the moment
Sky has that I've come a long way from France and I'm a bit jaded look about it
Wavy and disturbed but all the action dried out of it

Kermit.de.frog

WheatenBriar wrote: »

Raining here near Arklow at the moment
Sky has that I've come a long way from France and I'm a bit jaded look about it
Wavy and disturbed but all the action dried out of it

It may be a bit unlikely but don't rule out and interesting evening yet.

WheatenBriar

Kermit.de.frog wrote: »

It may be a bit unlikely but don't rule out and interesting evening yet.

Aye there's very very little on the northern tip of that shower train but it looks like that activity west of Cornwall is traveling up that line and if it continues to do so it will reach Wexford and Wicklow ?
Trouble is ,an encroaching front from the west will be moving that line East

Is it the activity that was previously modelled to miss the East and head into Cumbria?
I forget

maquiladora

Tony Gilbert on UKWW going for surface base thunderstorms today over Ireland from the eastward moving cold front. We'll see I guess.

V_Moth

Isle of Skye and NW Scotland getting a pasting atm. Best cam I can find so far:

http://www.whiteheatherhotel.co.uk/isle_of_skye_webcam.html

Iancar29

V_Moth wrote: »

Isle of Skye and NW Scotland getting a pasting atm. Best cam I can find so far:

http://www.whiteheatherhotel.co.uk/isle_of_skye_webcam.html

Very well could be a supercell, "hook " visible on radar

Iancar29

Liking the WRF's take on this evening breaking out convection within an area of strong instability compared the the NMM which has it further west in more stable air.






Hmmm might have to try chase this :cool:

V_Moth

Iancar29 wrote: »

Very well could be a supercell, "hook " visible on radar

Nice. Moving through very quickly - pity it is in an area with hardly any places likely to have a webcam!

maquiladora

Nice line of cells over Cornwall too.

http://www.sat24.com/en/gb?ir=false

Storm 10

Hi Maq are we likely to see anything out of this rain in the South West moving North, the only mention of rain in the 1pm forecast was rain in the South West and West moving North no mention of thunder anywhere.

maquiladora

Storm 10 wrote: »

Hi Maq are we likely to see anything out of this rain in the South West moving North, the only mention of rain in the 1pm forecast was rain in the South West and West moving North no mention of thunder anywhere.

Maybe but I doubt it. I think if anything does kick off here it will probably be further north and east of that. But there's no guarantee there will be any storms here at all.

Storm 10

maquiladora wrote: »

Maybe but I doubt it. I think if anything does kick off here it will probably be further north and east of that. But there's no guarantee there will be any storms here at all.

Thanks Maq, very sticky here and flat calm maybe a breeding ground for something later , looking at the radar its getting larger as it moves up.

Danno

Potent rainfall radar returns over west Cork and the N Cork/S Limerick border in the last radar return (raintoday.co.uk)

Still no Irish sparks yet... http://www.lightningmaps.org/realtime

Iancar29

Danno wrote: »

Potent rainfall radar returns over west Cork and the N Cork/S Limerick border in the last radar return (raintoday.co.uk)

Still no Irish sparks yet... http://www.lightningmaps.org/realtime

Elevated messy stuff... the slight clearance moving up is when the potential will be

pad199207

Cumulus Clouds visible now from Naas over the Wicklow direction

Storm 10

Gone very dark and muggy in Galway now from the South, nothing showing but we live in hope

WheatenBriar

pad199207 wrote: »

Cumulus Clouds visible now from Naas over the Wicklow direction

Aye,I see altocumulus here too all to the south camouflaged by a general bank of cloud like an approaching dry front if you get me?
Not optimistic for activity here but sparks are possible over the Wicklow mtns with that Aughrim temp of 27c (25.4 here last I looked)

jimmynokia

The UK is having a good show , not looking good for us is it...

Storm 10

Bucketing down in Galway now but no sparks

Danno

Sunshine here now and temps are shooting up 23.3c now.

Iancar29

jimmynokia wrote: »

The UK is having a good show , not looking good for us is it...

The cold front isn't even here yet... don't lose all hope until the 7 at least...

jimmynokia

Iancar29 wrote: »

The cold front isn't even here yet... don't lose all hope until the 7 at least...

Haahah.. I've camera's at the ready and I'm impatient.

Iancar29

Looks like clouds trying to go up in the midlands ...

Danno

As posted over on the other thread...

Just shy of 24c here now (23.9c) and prolonged sunshine for the past hour or so. Plenty of surface heating going on which bodes well for later if other factors come in to play.

pad199207

Cell developed over The Silvermines if I'm not mistaken

Danno

pad199207 wrote: »

Cell developed over The Silvermines if I'm not mistaken

Not quite, developed over the Galtees and pushing north just west of Thurles.

Moneygall the firing line... watch out Barack O'Bama plaza!

highdef

Just, we seem to have lift off in Tipp!!! Fantastic returns on radar. No sparks yet but would expect some any moment now

Danno

highdef wrote: »

Just, we seem to have lift off in Tipp!!! Fantastic returns on radar. No sparks yet but would expect some any moment now

Sparks on my detector here the last few minutes - incidentally there is another detector in Thurles also but I think it needs a few other stations confirming on the lightningmaps.org to report a strike.

cyclops999

Starting to bubble up nicely over Athlone

Rougies

highdef wrote: »

Just, we seem to have lift off in Tipp!!! Fantastic returns on radar. No sparks yet but would expect some any moment now

Yep, strike just detected from that cell.

pad199207

Lightning just North of Nenagh.