Storm & Convective Discussion - SPANISH PLUME - 30/06/15 onwards

[Chris K]

Havent seen it posted yet - UKASF updated forecast for today/tonight. It was issued late morning I only saw the precious version.

Day 1 Convective Outlook

VALID 06:00 UTC Tue 30 Jun 2015 - 05:59 UTC Wed 01 Jul 2015

ISSUED 10:16 UTC Tue 30 Jun 2015

ISSUED BY: Chris/Dan

As is fairly typical in destabilisation of hot air masses over the British Isles, there is a large amount of uncertainty surrounding the detail in any thunderstorm development during this forecast period.

... SCOTLAND / NORTHERN IRELAND ...

Within the warm sector, strong diurnal heating will yield 500-1000Jkg-1 CAPE. This is likely to remain capped, with most recent NWP products keeping most areas largely dry; however, the passage of a shortwave trough may just coincide with near-peak heating to develop a couple of showers/thunderstorms late afternoon, more especially into the evening. Placement also remains quite uncertain, hence a rather broad ISOL, with UKMO Unified Model products favouring NW Scotland/Great Glen area, while NOAA products are more keen on eastern Scotland. Have kept a SLGT over both areas to highlight risk for now, but may need to be downgraded to ISOL if conditions remain to look isolated/unlikely.

... EAST ANGLIA / HOME COUNTIES ...

AcCas will spread northwards this evening associated with an area of mid-level instability, drifting north from northern France to S/SE England. Some destabilisation of this layer may result in a few high-based showers or thunderstorms over the ISOL area as this zone continues to drift northwards during the overnight hours.

... SW/CS ENGLAND / S + E WALES / S + W MIDLANDS ...

Destabilisation of a warm and increasingly moist airmass will occur overnight, with scattered thunderstorms erupting over the Brest peninsula, and then migrating/expanding northwards towards SW/CS England overnight (and then moving to the W Midlands/S Wales thereafter). Greatest uncertainty surrounds timing, with the GFS consistently the quickest (arriving late evening into early hours), EURO4 consistently in the middle (ie late tonight) and ECMWF slowest (mainly beyond 6z Wednesday). In either case, 900-1400 Jkg-1 MLCAPE coupled with 30-40kts DLS, backed low-level winds and curved hodographs favour the potential for organised storms, perhaps with rotating mesocyclones/high-based supercells capable of producing significant hail and very heavy rainfall given PWAT >30mm. This may perhaps need an upgrade to SVR depending on developments later today.

[Mapantz]

I see some AcCas making inroads from the Southwest.

[William Grimsley]

Sky has turned remarkably unstable now, streams of Ac Cas to my east, overhead and also to my west, lots of virga around from light showers to my SE and S and turning warmer now as wind is slowly decreasing, it's a start!

[Bolt from the Blue]

Just took a pic looking to my SW, could this be the one in the Channel?



I have heavily edited the pic to bring out the clouds

 

[Darren Bown]

Here's ukasf for tomorrow.

As the result of southerly flow from Iberia, southern Europe and northern Africa a hot and humid airmass will be in place across Britain. A surface low will cross Ireland in association with an upper trough to the west of Britain. The interaction of this forcing and the hot, humid airmass could produce some significant thunderstorms, especially across western parts of Britain. CAPE values of 1000-1500 J kg-1 are possible across NW England and S Scotland by the afternoon and this location will be the focus for the most intense thunderstorms. More isolated thunderstorms are possible in SW England during the morning hours, and further east later in the afternoon.

Edited June 30, 2015 by Darren Bown

[Generalelectrix]

Got some of those UFO clouds forming

those are Lenticularis or "Foehn" clouds, you happen to be near the base of some mountains?

 

regards

 

Ralph

 

Edit:.. and that means that nothing will happen (yet)

Edited June 30, 2015 by Generalelectrix

[Mark Parsons]

Just took a pic looking to my SW, could this be the one in the Channel?

I have heavily edited the pic to bring out the clouds

 

Not coming to much and the storm to the west of the channel islands seems to be moving NE to hit the IOW as usual!!

Edited June 30, 2015 by Mark Parsons

[Ben Sainsbury]

Here's ukasf for tomorrow.

As the result of southerly flow from Iberia, southern Europe and northern Africa a hot and humid airmass will be in place across Britain. A surface low will cross Ireland in association with an upper trough to the west of Britain. The interaction of this forcing and the hot, humid airmass could produce some significant thunderstorms, especially across western parts of Britain. CAPE values of 1000-1500 J kg-1 are possible across NW England and S Scotland by the afternoon and this location will be the focus for the most intense thunderstorms. More isolated thunderstorms are possible in SW England during the morning hours, and further east later in the afternoon.

Awh bless lucky Bristol hopefully? Obviously not, nevertheless in terms of Friday I believe will be a considerably easterly affair in terms of home grown storms and imports. For tonight I have a feeling tonights forecast will be spot on, not a cloud in the sky here yet.

Edited June 30, 2015 by Ben Sainsbury

[Mapantz]

There's some lovely clouds arriving now.

[ztam]

Not coming to much and the storm to the west of the channel islands seems to be moving NE to hit the IOW as usual!!

I am on the isle of wight  

[William Grimsley]

There's some lovely clouds arriving now.

20150630_181428_HDR.jpg

You want to see what it's like here, that's nothing, the whole sky is covered!

[Gordon Webb]

really don't want anything here overnight tonight even if the risk is low as am travelling to skegness for a day out of course that should be relatively fine tomorrow it's walking to my bus tomorrow I have concerns about , just how much of the midlands are we talking about Met office suggested far W portions

 

edit - just saw latest BBC forecast doesn't look too bad for me , just pleased I'm going to skeggy rather than blackpool

Edited June 30, 2015 by Gordon Webb

[Wet'n'Dry]

You want to see what it's like here

 I want to see it 

[Mesoscale]

Lets see how this plays out, the last couple of times its been a bust lets see if the north can muster anything tomorrow, its a shame we cant get them in my location. 

[Mapantz]

I can't do much about the power cables lol

[StormChaseUK]

I can't do much about the power cables lol

20150630_182208.jpg

Very nice I had similar cloud to that in August 1994, later in the night the lightning was amazing.

[Tempest]

Wish I had something nice or exciting to report...this is makin' me

[Flash bang flash bang etc]

This forecast is becoming awesome!

[East_England_Stormchaser91]

Nothing here but sizzling hot temperatures and unbroken sunshine. Reminding me of 2006 so much today.

Hunstanton beach today

[Gordon Webb]

Awh bless lucky Bristol hopefully? Obviously not, nevertheless in terms of Friday I believe will be a considerably easterly affair in terms of home grown storms and imports. For tonight I have a feeling tonights forecast will be spot on, not a cloud in the sky here yet.

 

ties in with met office warning

[davehsug]

Just thought I'd mention, following some recent discussions, not a contrail in sight today and still no storms!

[Generalelectrix]

I can't do much about the power cables lol

20150630_182208.jpg

..Loaded Gun Sky..

 

Ralph

[jamesbhx]

Updated forecast for Shoreham Airport and Gatwick says a 30% of storms between 9pm tonight and 5am tomorrow morning which is encouraging as previously there was nothing forecast. Its based around the area of convection currently around the Channel Islands which has a N/E drift to it.

[JonGill]

This is sky just now in Norton Fitzwarren near Taunton.

looking east:

looking SSE:

[Pat Butcher]

Hi folks,

Just to check - UKMO have downgraded my part of the world to zero precipitation tomorrow. Assuming that the model gets it spot on (big assumption I know), does that mean guaranteed no storms?