UK Convective General Discussion & Forecasts - May Into June 2012

[Lauren]

In regards to there being less storms. I dont have official data or anything, but the storm diaries I kept as a child from 1993 to 2007 show a considerable drop in not only the number but intensity of storms. That decline seemed to happen quite obviously from aboit 1999.

[Lewis]

Morning guys.

Here's my take on things with storm chart.

My Summary for today's thunderstorm risk

After a bright start to the day for many areas, Eastern and South Eastern areas in particular, as we head through the day they will be an increasing risk of showers for many areas, we start off with Central Northern England, Pennine regions and Yorkshire and Northern Lincolnshire around 11 am this morning, showers will be heavy for these areas and organized for central parts of these regions although thundery activity will be limited, there is a small chance of these areas experiencing thunderstorms although energy is limited for these areas, with the majority of the energy running from the Wash across to North Wales southwards.

Around 11am across Wales showers will start to form, becoming organized as we head in to mid day-early afternoon, showers cropping up just about anywhere east of Wales pushing eastwards, showers will become more widespread and thundery, with some potent cells for these areas.

Areas greatest at risk is the West Midlands, with the risk extending eastwards across central southern parts, and later in to the East Midlands, EA and also the SE of England.

For EA and the SE thunderstorms will be rumbling until sun fall. There is a moderate risk for severe thunderstorms for these areas.

During these storms the risk of torrential rain and flash flooding is very likely, along with frequent lightning.

Regards

Lewis

Edited May 30, 2012 by UK Storm Chasers

[tara303]

well. i booked today off as holiday when things were looking juicy last week. Woke to grey cloud cover, sun now seems to be burning this off but very cool temp, 13c or so. off to do a few chores and see what happens... here's hoping!!

[syncmaster]

Morning guys.

Here's my take on things with storm chart.

My Summary for today's thunderstorm risk

After a bright start to the day for many areas, Eastern and South Eastern areas in particular, as we head through the day they will be an increasing risk of showers for many areas, we start off with Central Northern England, Pennine regions and Yorkshire and Northern Lincolnshire around 11 am this morning, showers will be heavy for these areas and organized for central parts of these regions although thundery activity will be limited, there is a small chance of these areas experiencing thunderstorms although energy is limited for these areas, with the majority of the energy running from the Wash across to North Wales southwards.

Around 11am across Wales showers will start to form, becoming organized as we head in to mid day-early afternoon, showers cropping up just about anywhere east of Wales pushing westwards, showers will become more widespread and thundery, with some potent cells for these areas.

Areas greatest at risk is the West Midlands, with the risk extending eastwards across central southern parts, and later in to the East Midlands, EA and also the SE of England.

For EA and the SE thunderstorms will be rumbling until sun fall. There is a moderate risk for severer thunderstorms for these areas.

Regards

Lewis

Edited May 30, 2012 by syncmaster

[Lewis]

Links not working Lewis :-((

Fixed it mate, could you delete your quote please as there was some small errors in the forecast that I made "typos" I have edited it now.

thanks mate

[Coast]

Morning stormies!!!

Don't look to ESTOFEX, TORRO or SkyWarn for signs of storms today!

UKASF so far the only dedicated site reporting as follows:

Forecaster: Chris

Last Updated: 2012-05-30 02:43:00

Valid: 2012-05-30 00:00:00 - 2012-05-30 23:59:00

Areas Affected:

S and E England

Synopsis:

Not dissimilar to previous days, slack flow will exist across Britain. The remnants of a front that has been across eastern England the last couple of days will move back northwards into Scotland as a warm front with a wave developing along it during the afternoon. An occluded front over Ireland will move into southwestern Britain during the afternoon and an upper trough will move west-to-east across central England.

Discussion:

A complicated synoptic setup which will be dominated by slack upper level flow ahead of a slow moving large-scale upper trough to the west of Britain, combined with and a slow moving smaller scale upper trough/short wave will be the trigger mechanism for potential showers and thunderstorms during the afternoon.

A warm front will move northwards during the morning allowing for warm surface temperatures to develop during the day, perhaps reaching 22-24C in places across southern England by the afternoon. This in combination with cooling conditions in the mid-levels with the approach of the upper trough (less capping than the last few days) will likely allow for more widespread convective activity than previous days. GFS CAPE values of up to 1000j/kg will develop during the afternoon, however higher resolution models are much more modest with the instability suggesting more likely 200-400j/kg (which seems more reasonable) across S/Cen England during the afternoon. This combined with surface heating and the transit of the short wave will likely develop showers towards late morning that will become more widespread in nature during the afternoon.

There is very little LLS/DLS in the SLIGHT risk area, therefore storms will remain unorganised and likely short-lived/pulse variety updrafts - with any stronger updrafts being trigged by various surface related boundary such as sea-breezes that may develop in East Anglia during the afternoon or surface convergence closer to the approaching occlusion in S England later in the afternoon.

Another inhibiting factor may be over-convection. Showers may become more widespread in the afternoon and limit surface insolation thus lowering the chance of more intense convection.

Overall there will likely be numerous showers, however thunderstorms could be fairly isolated in nature. Main risks: heavy downpours / occasional CGs.

21st OWS have something tantalizingly close to our shores, but is it close enough???

The lightning possibility ensembles look encouraging!

Aviation weather report for today also good with isolated storms possible in the South at 37,000ft :

HiRLAM has little CAPE around:

But GFS much more bullish!

SB CAPE looking better:

If we can just get some heat into things!!!

Overall, some may be lucky today, perhaps on the South coast in the afternoon, then moving further inland:

I think it's going to be touch and go though today, so keep the eyes on the radar and detectors!

[dallas]

Cheers Lewis and coast, see how it goes

[Lewis]

Some nice showers in the channel south of cornwall, steadily pushing ENE.

Could be some action soon for the South Coast

Edited May 30, 2012 by UK Storm Chasers

[Kain]

Another day to watch the east get the goods Can't decide to go see the flame go through much wenlock?

Anyway last night was probably the most humid night we have had all through this warm period, hardly any sleep at all. Not alot of interest up there this morning either yet, but the sun is peaking through.

[BrickFielder]

Looks complicated enough for forecasts to be very difficult, but it looks like quite a few people expecting storms may be disappointed. Forecast SkewT's suggest cloud height may be limited and I guess we would need to see the midday soundings before we really get an idea. The forecast SkewT for southampton suggest storm development would be difficult, however I suspect the forecast SkewTs are likely to be slightly wrong.

The first factor coming into play today is low level moisture advection with the lightning wizard charts suggest two distinct bands crossing the UK. The first of these two bands I think is likely to trigger convection particularly just inland from the south coast and might well benefit from insolation ahead of it. As to whether clouds will reach thunderstorm level then I am not sure.

The second factor then may come into play which is areas of wind divergence aloft which will lift air potentially above the convective top. The south coast from midday to mid afternoon seem likely areas for this to occur along with perhaps an area in the north midlands.

The third factor is low level wind convergence areas which again given insolation should create convection, although this may be complicated by another factor - orographic lifting especially across wales and the south west. Notice how winds converge over the south west, parts of wales and the north midlands.

The forth Factor is the potential development of a surface low late on over the north midlands which shows up on the 850 wind charts.

The fifth factor is downstream cloud cover from orographic and convergence zone lifting.

Any predictions for today should come with a large caveat as a result. Key areas for me would be along the south coast early afternoon and potentially the north midlands later, South Wales and the south west. It is entirely possible that there will be no storms at all today, but with so many factors coming into play my hunch is we will.

Cloud top temperature charts by lightning wizard suggest some areas may still see storms.

[Robbie Garrett]

Another day to watch the east get the goods Can't decide to go see the flame go through much wenlock?

Anyway last night was probably the most humid night we have had all through this warm period, hardly any sleep at all. Not alot of interest up there this morning either yet, but the sun is peaking through.

I am quite skeptical that we will get anything, MetOffice was pretty confident the storms wont actually happen. The above post also highlights this fact....

Edited May 30, 2012 by Robbie Garrett

[syed2878]

Seen the bbc forecast and the met offices on their websites they don't mension thundery showers or t-storms for brum today.

[Neilsouth]

Morning guys.

Here's my take on things with storm chart.

Wrong already...

Take all storm risks with a large pinch of salt today, it's lovely with blue sky so far wish it lasted

[dallas]

Cheers Brick for the detailed forecast, it seems to be following the rest of the week i.e wait until the afternoon to see if anything builds. It felt cooler this morning so hope there is some rapid heating.

[Kain]

I am quite skeptical that we will get anything, MetOffice was pretty confident the storms wont actually happen. The above post also highlights this fact....

Yup, but been reading Brick's post, it really is a mess out there today. I guess we can all be clutching at straws today. Still days like these and always spring some nice surprises!

[Lynxus]

Some minor convection round here, nothing special.

[Lewis]

Wrong already...

Take all storm risks with a large pinch of salt today, it's lovely with blue sky so far wish it lasted

Blimey give it chance to kick off, you quoted my forecast at 9:30 an hour and half before I expected convection to take place, i bet your one of those that sits in front of the TV yelling at the national forecast lol.

[Robbie Garrett]

PROB30 TEMPO 3014/3018 4000 +TSRA for London City and Southend... so keep your hopes up but at a 30% Chance!! If you live in the South East.

I think there's not much interest as the occluded front looks to break up, and is a rather weak affair. Keep your eyes pealed on the imports to the south west from the Channel Islands/France, that is probably what may give us some activity. It seems to be growing.

[Liam Ellis]

These clouds looks quite unstable in Cardiff. Looking West.

.

Edited May 30, 2012 by Liam Ellis

[Robbie Garrett]

An area of interest for some imports from the Channel.

[Eskimo]

Well the Metoffice thought we'd get storms yesterday and guess what happened, not even a single shower in most places. Anything therefore can happen.

[Cloudwatcher]

Well, I can be pretty confident that nothing thundery will kick off here today, or this week for that matter. Just not hot enough and too much low cloud. Five years and counting since we had a storm.

[A.J]

These clouds looks quite unstable in Cardiff. Looking West.

.

similar skies here in my part of the west midlands...convection has initiated and interestingly, it's mid-level convection as opposed to surface convection, quite a lot of AcCas which is already showing signs of towering

[NUT]

Unlikely anything is going to happen here too as we still stuck with low cloud. Wasn't really sure if it was going to happen as far north as here today anyway

[Arnie Pie]

A couple of towers have just sprung up on my Western horizon were i`m presuming, the occluded front is situated and heading this way

High level convection seems to have started around Birmingham ATM

22c

fingers crossed

Edit; Yes Aj........ and more elegantly put

Edited May 30, 2012 by Arnie Pie