Convective/storm Discussion 5Th August >>

[Lewis]

The metoffice have issued severe weather warnings (watch) for the following areas;

East of England

Yorkshire & Humber

London & South East England

East Midlands

North East England

They expect heavy thundery rain to push N/NE tonight/early hours, and then some into friday. What do you guys think to this? I can't see anything happening, going by the radars and the way today has panned out.

Regards

Lerwis

[Coast]

Not sure myself about tomorrow evening.

Or into Friday....

Classic case of a look at the 00z and 12Z Skew T's and then the radars and detectors as this one is going to be too close to call again (even then many will be disappointed).

[SnowJoke]

Looking at the various charts and atmospheric conditions. The rain indeed looks convective with embedded thundery outbreaks. This looks like a classic example of elevated convection taking place as the front is envigorated by the warm humid airmass being advected from the SE and interacting with the stalled front. In these situations heavy thundery rain and possibly stronger isolated cells don't require huge ammounts of cape for iniation.

Edited August 5, 2009 by SnowJoke

[saint]

This thread is for tonight...... But some in this thread are more concentrating on tomorrow evening....... why? More chance of something tomorrow evening?

[Harry]

This thread is for tonight...... But some in this thread are more concentrating on tomorrow evening....... why? More chance of something tomorrow evening?

Possibly, it does appear tomorrow evening is the more promising! But to be honest, tonight could produce something also - the signs are there.

Appears to be something starting over NW France - either that or it's just insignificant, or anaprop.

[xerxes]

Looking at the various charts and atmospheric conditions. The rain indeed looks convective with embedded thundery outbreaks. This looks like a classic example of elevated convection taking place as the front is envigorated by the warm humid airmass being advected from the SE and interacting with the stalled front. In these situations heavy thundery rain and possibly stronger isolated cells don't require huge ammounts of cape for iniation.

Agree with that. The frontal boundary itself will likely provide an element of forcing. It will again be close to a nowcast event, as in often the way with potential thundery activity

Possibly, it does appear tomorrow evening is the more promising! But to be honest, tonight could produce something also - the signs are there.

Appears to be something starting over NW France - either that or it's just insignificant, or anaprop.

Not sure about the "precipitation" in NW France. Could well be anaprop. However some good storms brewing in NE Spain now. They'll be too far east for us I guess but it highlights the instability on the eastern side of the front

http://www.sat24.nl/sp

[chrisbell-nottheweatherman]

OK, I suspect this would, were it not for the "current affairs" aspect of this, be better in the learner's area, but here goes:

Compared to the guide in the NW guides for storm setups - Spanish Plume, how much different is the forecast situaton for tomorrow evening/Friday morning?

[A.J]

A few things to note on the sat imagery and radar....1) a nice cell has popped up north of london along the frontal boundary, thunderstorm in the making?.Its showing up quite nicely on visible satellite and on radar...see images below.....2) An area of rain developing in the channel, south of the devon/dorset coast, tonights thundery rain developing I guess.....and 3) an interesting area of mid/high level cloud streaming up from biscay, over cornwall, wales in to the west midlands...Is this a trough developing?, as it seems, looking at the FAX charts, that its not associated with the cold front over C/S England....4) Altocumulus Floccus, with a hint of Castellanus here in the West Midlands....Do the clouds know something the charts dont?

[PB22]

The trough is back for tomorrow night:

http://www.meteociel.fr/ukmo/fax/fax36s.gif

[maidstone weather]

The trough is back for tomorrow night:

http://www.meteociel.../fax/fax36s.gif

and the cold front is MUCH further west!

[dogs32]

here's a bit more ramp

Louise from the BBC said that they are keeping there eye's on the development for Friday because there is a potentail for some very heavy rain with embedded TS

She wouldnt say where

but it certaintly isn't Glos

Edited August 5, 2009 by dogs32

[Neilsouth]

Cells firing now , in the channel towards the south

[maidstone weather]

Cells firing now , in the channel towards the south

not sure where you got that from Neil?

anything expected for Friday night? the UKMO 12z is showing some very heavy and widespread rain on Friday night:

Edited August 5, 2009 by maidstone weather

[SnowJoke]

Thing to note on why the trough has re-appeared on the MET fax charts is a new surface low which has developed over northern france, which wasn't there earlier. This bodes very well in my opinion for seeing more in the way of thundery activity as the low pressure redevelops the trough over the SE and keeps the front stationary, or pushes it back further westrwards. This will allow a longer peroid for the sytems to interact and feed off the warm humid airmass. Dare I say it, but it could turn out to be alot more electrified than first thought

[PB22]

Cold front is still over the southeast on Friday now:

http://www.meteociel.fr/ukmo/fax/fax48s.gif

I suspect that UKMO T+60 chart may be faulty MW, if you look at the larger picture, there seems to be an explosion of precipitiation everywhere atT+60 when compared to the T+48 and T+72 charts...

T+48:

T+60:

T+72:

But there may be another pulse run northwards given that the T+48 FAX still has the cold front over the southeast....awaiting the T+60 FAX chart with interest.

[dogs32]

Liam Dutton now saying Central and Eastern areas could see some heavy Thundery shower's developing at any point through Thursday and Friday

Edited August 5, 2009 by dogs32

[maidstone weather]

Cold front is still over the southeast on Friday now:

http://www.meteociel.../fax/fax48s.gif

I suspect that UKMO T+60 chart may be faulty MW, if you look at the larger picture, there seems to be an explosion of precipitiation everywhere atT+60 when compared to the T+48 and T+72 charts...

T+48: http://www.meteociel...8-594.GIF?05-19

T+60: http://www.meteociel...0-594.GIF?05-19

T+72: http://www.meteociel...2-594.GIF?05-19

But there may be another pulse run northwards given that the T+48 FAX still has the cold front over the southeast....awaiting the T+60 FAX chart with interest.

i did wonder that - however new trough on the T60 now! http://212.100.247.145/fax/PPVJ89.png

This could be better than any of us are expecting

Will have to wait and see what the updated BBC charts from 9pm onwards show to see if the rain is true or not

Edited August 5, 2009 by maidstone weather

[PB22]

Yes, although the cold front has cleared through by then. All subject to change however given the changes we have seen on the output this evening!

[Neilsouth]

not sure where you got that from Neil?

South of the uk , not south of us in kent

Just following in from nw france , i can see them on the sat and euro radar. However they don't seem all that active yet

[maidstone weather]

comparing the charts, the UKMO 12z is about 6 hours faster than the GFS 12z in pushing the precip into CS Eng?

[PB22]

Some activity over Cambridgeshire, the Fens, Lincolnshire by the looks of things...

[chrisbell-nottheweatherman]

Some activity over Cambridgeshire, the Fens, Lincolnshire by the looks of things...

Indeed. Do you watch Look East and the forecast therein, Paul? I think I'm right in saying that the forecast comes from Weathercast; certainly, Julie Reinger was talking about some hefty rain for the western half of the region this evening.

Indeed. Do you watch Look East and the forecast therein, Paul? I think I'm right in saying that the forecast comes from Weathercast; certainly, Julie Reinger was talking about some hefty rain for the western half of the region this evening.

Sorry, make that Weatherquest.

[PB22]

Indeed. Do you watch Look East and the forecast therein, Paul? I think I'm right in saying that the forecast comes from Weathercast; certainly, Julie Reinger was talking about some hefty rain for the western half of the region this evening.

I do often catch it, but I missed it this evening! They seem to use the same data as the BBC national forecasts? Maybe they have changed though?

[chrisbell-nottheweatherman]

I do often catch it, but I missed it this evening! They seem to use the same data as the BBC national forecasts? Maybe they have changed though?

They use the same graphics, but, gven that Jim Bacon and (I think) Phil Garner are Weatherquest guys, I doubt they'd use MetO data, or at least, I'd expect them to put their own spin on it. In fact, thinking about it, Jools sometimes says "the computer's showing X, but actually, I think Y", which suggests that Jim and the WQ folks (including a namesake of myself) interpret it given their own data.

[Neilsouth]

Storm gone off nw parts of EA