Upcoming Convective / Storm Risk Discussion - w/c 12th May

[Supacell]

Currently just west of Ashbourne and feels warm with strong sunshine. Already little cauliflower tcu's starting to build here too.

[Stuart]

Good luck to all today

[BrickFielder]

  Not much to add from yesterday really. NMM is suggesting some low level convergence and an area of vorticity advection across the UK.

 

Mid level lapse rates look OK (You dont get much better than this in the UK - 32 Max typicaly)

 

Instability looks on the low side though, with surface temperatures tending to limit updraft strengths.

 

There is a little turning of the winds in the lower levels in some areas, but its not concentrated in the lowest layer , with very little speed shear in the lowest level and temperatures might limit updraft strengths. However it could mean that moist air feeds into storms are unlikely to be shut off by any downdraft or clouding out.Just wanted to pick up on a few good points made in the comments. So potential for the upper region of the more vigorous updrafts to be pushed forward in relation to storm motion, increasing longevity and perhaps enhancing strength. Steering mid-level winds, however, will be light, so storm motion rather slow.Steep low to mid-level lapse rates supports generation of moderate-sized hail and gusty winds.  (Weather09).Fairly weak CAPE will preclude severe weather developing, although slow storm motion could give rise to localised flooding as they are likely to last a while.Around 30-60knts of deep layer shear will allow separation of updrafts and downdrafts which brings the probability of more organised storm activity (Supacell)I know the TT index should't be taken as an indicator on it's own, but putting the Netweather Extra NMM ones in amongst the other GFS charts this morning, makes it pretty interesting this afternoon: (Coast)

 

 

Key risks I think are from slower moving storms producing hail and significant downpours. So a good chance of some localised flooding if storms materialise (Triggers are a bit weak). Beyond that it is a wait and watch the radar.

 

[Coast]

The Cu's building up seem to fit in with the general consensus in the RASP charts:

 

 

 

[Liam Ellis]

Nice bubbly clouds around Cardiff, but plenty of sunshine on offer as well. Hopefully we'll get some action later on! 

[DAVID SNOW]

Looks like we have a convergence zone over old London town?

 

Maybe not just solar heating,and a couple of extra degrees from the city.

Edited May 16, 2013 by DAVID SNOW

[Boro Snow]

from were i live i can see the dales which are about 10/15 miles away and the cloud is defo bubbling up

[Marcus_surfer]

Towering clouds here some big showers already brewing a few miles north of here

[Supacell]

Thanks guys for the updates on here.

I am currently in Stoke and clouds really building here. I am planning on heading into Shropshire where i feel some action may occur later.

[Cheshire Freeze]

Thanks guys for the updates on here.I am currently in Stoke and clouds really building here. I am planning on heading into Shropshire where i feel some action may occur later.

 

15 miles WNW of you in Crewe and it's the same here.

[Wilxy]

Cu starting to build all around now just renewed my NW radar as i feel i may need to use it today good luck to all already looking intresting across wales.

[Cloudwatcher]

Starting to get a build up of cloud here but it's the usual boring stuff, and the temperatures dropped from this morning. Nothing doing here today I'm afraid (again,lol)

[Cheshire Freeze]

13.11 and nowt spectacular on the radar yet.

[Coast]

13.11 and nowt spectacular on the radar yet.

 

The charts aren't indicating anything until later this afternoon, after the sun has performed a bit of magic on the land!

[Kain]

CAPE has vanished?

[samadamsuk]

I'd say more of a slight inversion going on - cumulus here is flattening out, or filling in - haven't seen any soundings, but if so that may well let cape build until the cap is broken later -

[Supacell]

Currently sat just outside Whitchurch and not going to move far until things start kicking off a bit more. Its really from about 4-5pm onwards that the charts show things kicking off but I have got here early to avoid having to cross Stoke etc during rush hour. I am hoping I am now more or less in position and can just sit and wait

[Cheshire Freeze]

Currently sat just outside Whitchurch and not going to move far until things start kicking off a bit more. Its really from about 4-5pm onwards that the charts show things kicking off but I have got here early to avoid having to cross Stoke etc during rush hour. I am hoping I am now more or less in position and can just sit and wait

 

That's if owt kicks off. Brickfielder did say there'd be a lack of a trigger.

 

Let's hope you haven't wasted your petrol eh.

Edited May 16, 2013 by CreweCold

[Supacell]

That's if owt kicks off. Brickfielder did say there'd be a lack of a trigger.

 

Let's hope you haven't wasted your petrol eh.

 

Yes lets hope so. Although often storm chasing is a gamble and you win some you lose some, nature of the game I suppose. 

 

Nothing much happening here yet (near Whitchurch) but I will wait until around tea time before giving it up as a bust. Very heavy returns from a cell over north Devon but other than that the heaviest cells are across Lincolnshire.

Edited May 16, 2013 by Supacell

[Boro Snow]

looking at the radar something seems to be happening lincs area

[Cheshire Freeze]

It was looking promising about 11am but then everything seemed to fall flat

[AWD]

the heaviest cells are across Lincolnshire.

Oh God, here we go again!! lol. ;) Edited May 16, 2013 by AWD

[Karl83]

I think between now and 7/8PM is our chance.

[nitro_deluxe]

I think more windows of opportunity should arise around 5ish on pretty much coinciding with the evening rush.

E W border, Herefordshire perhaps M42 corridor running up the M5 Worcester area and quite poss Bridgnorth Shropshire too.

Certainly not widespread stuff by any means - many will see hardly a drop.Very hit and miss affairs today folks.

[Panayiotis]

There are a few cells over Northern France which have produced lightning, what would be the chance of them reaching us as they are moving northwards?