11th Aug 2011 - Storm/convective Forecast Discussion And Reports

[Stuart]

Last Updated: 18:04 Wednesday, 10th August 2011

Valid: 00:00 Thursday, 11th August 2011 - 23:59 Thursday, 11th August 2011

Areas Affected:

SLGT: England, Wales, S Scotland, Northern Ireland

Synopsis:

A very elongated area of low pressure underneath a very zonal upper flow will dominate the weather across the United Kingdom on Thursday. The main focus of interest will be along the eastward-moving cold front which crosses the forecast area between 0z-13z BST. Discussion:

Convection and lightning has been occuring along the cold front over the Atlantic throughout Wednesday. Whilst upper support will gradually weaken as it moves further eastwards, there are continued suggestions of further isolated lightning along the front as a result of embedded convection. A couple of hundred J/kg of MLCAPE is expected, and ELT's as low as -20C locally are possible. Any activity should have cleared into the North Sea by early afternoon.

Given high values of PWAT, any convection that does develop along the front has the potential to be quite heavy and give locally high rainfall rates, but given the speed of the front such downpours are not expected to last for any prolonged period of time.

Up to 30kts DLS is likely, although this rapidly weakening during the morning, and this combined with up to 30kts LLS does increase the risk of a tornado along the front, but this risk significantly decreases during the morning hours.

During the afternoon hours, given some diurnal heating, there is a chance of an isolated thunderstorm developing across NE/E England. If this does occur, such activity will slowly migrate SEwards across into the North Sea.

http://ukasf.co.uk/storm-forecasts/68

[Jane Louise]

http://www.estofex.org/

Hmmm, a 15% chance but will we see anything? :huh:

[Carl46Wrexham]

http://www.estofex.org/

Hmmm, a 15% chance but will we see anything? :huh:

As the Churchill Dog would say.....Errrrrrr No!

[Coast]

http://ukasf.co.uk/storm-forecasts/68

http://www.estofex.org/

A bit of consistency form the two forecast sites today, but does that mean convective activity?

21st OWS say not:

The MetO version says extreme SE corner:

WAFC Washington Aviation weather says not:

There's a smidgen of interest around some coasts for the KO index:

Some convective clouds showing in the soaring index across a band in Northern England:

CAPE not special, peaks around mid afternoon:

Shear is minimal:

Convective rain:

Some lift over East Anglia:

Lower level lapse rates through the middle band of the country:

But a better tornado chance chart for Avon and Somerset:

All in all not wonderful. A very slim chance of a rumble of thunder and the same for an odd funnel or tornado later on. Not a totally inspiring set of charts though.

[sunny scunny]

A heavy shower has just passed through here, with another one about to arrive shortly after according to the radar

[Harry]

Today looks largely uninteresting IMO.

Imagine if those charts for 7 days from now (Thursday 18th Aug) came off...... Alas much to change I fear. Nevertheless such synoptic charts IMO are the GOLD NUGGETS we hope for - ripe for widespread thunderstorms whether you're in Kent, Cornwall, Aberdeen or Belfast!

[Raidan]

Heavy rain here this morning but has stayed dry since,Not expecting anything today.

[Jane Louise]

No, not a lot happening here either. Not enough potential it seems for today! :unsure:

[IanR]

just the usual drizzle today, no thunder in july here and , and the clock is ticking now for the so called storm season(what a joke)

where did it all go wrong,

right, thats it, I am inventing a time machine to go back to the eighties and nineties

or I could just move to the east

[Dom W]

Drizzly and fog all day. Raining more heavily now.