Uk Convective General Discussion & Forecasts - 2012

[Stuart]

we getting some thunder here at the mo

[Robbie Garrett]

Both tuesday and more so wednesday looking good for storms. Interesting that on wednesday there is some suggestion of some deep convergence running up the east of the country from london, through east anglia and up the north east, Wednesday looks a fairly active day at the moment.

Looks like the risk could hang on into thursday especially for more southern parts. Looking good for here for all three days!

Edit: Just for fun - gfs modelling a little plume right out at the end of the range...

I have a bloody assessment at Acton Town this Wednesday with London Underground!! JUST MY LUCK!! LOL !!

I saw that, looks interesting... Might be a very good showery convective April!!

[Weather Wizard]

I was hoping for better on estofex only small chance of lightning.

[MP-R]

Anyone noticed a few squall lines appearing within this area of rain? One just went through here with gusty winds and driving rain but calmed down again now.

[Aaron]

Yes I noticed a squall line passing over Sheffield to Hull earlier

[Aaron]

Another squall has formed from mid Wales to the north Midlands

[Andy Bown]

I would expect tomorrow to have the most widepsread showers of the week and more than likely them occuring from the word go

on coastal regions exposed to the Westerly following today's/tonight's fronts. One particular focus for me would be along the Bristol

Channel and running inland throughout the night - where inland will depend on the exact wind direction but quite a lively streamer

is the regular occurence in such set ups with it easing off by late morning.

Through the day tomorrow showers will become more scattered but heavy/torrential with some hail/thunder with some stunning

convection likely across much of the country.

From then on it's a matter of where troughs and convergence lie as the LOW slowly drifts away and fills, with there being plenty of

sunshine and probably cold nights due to clear sky.

So for me a good few days (after tomorrow) of 'clean convection' where days start clear and clouds bubble up from around mid

morning leading to scattered showers by lunch time with these becoming heavier through the afternoons.

[Lewis]

A deep upper trough looks set to head South Eastwards throughout Tuesday and Wednesday, slack low pressure at the surface will make way for conditions favorable for convective instability.

The current data I have had a look through is taken from the GFS low res model, it gives a rough idea on conditions although the NMM model which is at a much higher resolution will confirm the percentages and certainity locally for convective action.

Showers will be widespread during tomorrow, thundery across NI, North Western England, and North Wales, during the day becoming more widespread across more central areas, at the moment N Wales & The West Midlands are more favorable later morning early afternoon for some heavy showers, with Hail, Torrentail rain, and Lightning.

A hundred to 200 ML CAPE with a negative Lifted Index of 0 to -2 across these areas along with favorable conditions for updrafts, will certainly increase the chances of the showers being thundery than not.

As we head into Wednesday the risk transfers to more Eastern and North/North Eastern areas.

Again with CAPE levels a little higher, and a more negative Lifted Index (LI), organized precipitation will bring an increasing chance of thunderstorms, a much higher chance for these areas with regards to the amount of energy out there, and certainly a greater chance of showers becoming more organized and forming a more general area of thunderstorms/thundery showers.

As we head into Wednesday afternoon, and then into Thursday, the risk extends southwards across central Southern England, East Midlands, and then London/Home counties.

North Wales/Chesire gap looks also to be a prime location throughout Thursday.

Although the chances of a MCS is relatively low, there is a possibility for a time during Wednesday where conditions may become favorable, and it's something to keep an eye on.

Will keep you guys updated.

Lewis

UK Storm Chasers/ UKSC

https://www.facebook.com/pages/UK-Storm-Chasers/320341941362083

Edited April 9, 2012 by ~SFL~

[Costa Del Fal]

Thursday has been upgraded on recent runs. One to watch out for and could be very similar to Wednesday. East Wales, the Midlands, SW Scotland, CS England and Ireland look best placed tomorrow. On Wednesday and Thursday the same applies but with the East joining in more so too though by Thursday you need to be about South of Manchester probably.

Edited April 9, 2012 by Blizzards

[Staffordshire]

Thursday could be similar to Thursday?

Thursday has been upgraded on recent runs. One to watch out for and could be very similar to Thursday. East Wales, the Midlands, SW Scotland, CS England and Ireland look best placed tomorrow. On Wednesday and Thursday the same applies but with the East joining in more so too though by Thursday you need to be about South of Manchester probably.

[Costa Del Fal]

Thursday could be similar to Thursday?

:lol: You can tell Its been a long day.

It should be similar to Wednesday!

[staplehurst]

Was going to say, if you're chasing on Wednesday you might want to stay local, Lewis. Recent GFS outputs indicating eastern and southeastern being favoured locations for a more concentrated risk of showers/storms, as surface winds become nice and light and converge near to coastal regions.

ML instability not too bad, though I'd take the GFS' CAPE/moisture projections with a grain of salt, for now. Might be potential for some funnel/spouts depending on the cloud base height during the period, so another risk aside from moderate-sized hail and gusty winds.

Should add, though, the risk of MCS development is 0%- lack of moisture and and non-existent vertical wind shear to support such storm mode.

Interestingly, I kept a close eye on the GFS today - it seemed to do better than the NAE on it's dewpoint predictions (of which the NAE is going for much colder dewpoints tomorrow than the GFS or the ECM so I remain a little more optimistic!)

[Aaron]

Thursday has been upgraded on recent runs. One to watch out for and could be very similar to Wednesday. East Wales, the Midlands, SW Scotland, CS England and Ireland look best placed tomorrow. On Wednesday and Thursday the same applies but with the East joining in more so too though by Thursday you need to be about South of Manchester probably.

Wow, this sounds really interesting for my neck of the woods!

[Costa Del Fal]

Wow, this sounds really interesting for my neck of the woods!

On Wednesday especially you may see something and a low chance tomorrow however your probably just outside of the higher risk zone. Saying that you will probably get something now ive said that! :lol:

[legritter]

just gone wild outside , steady rain just gone very heavy .wind picking up ,the start of an active week folks ,lets hope most of us get in on the action ,a squall is passing through ,wind gusty ,rain v heavy its easing off a little now lasted about 7 mins cheers gang

[Staffordshire]

Where would you say the high risk zone is?

On Wednesday especially you may see something and a low chance tomorrow however your probably just outside of the higher risk zone. Saying that you will probably get something now ive said that! :lol:

[Supacell]

An interesting week coming up and possibly the first proper convective potential of the year. Unfortunately it coincides with when I am at work, although if any showers/storms can hold into the evenings then I have a probability of catching something. Next week is a typical April showers set up.

And well done Stuart on getting something, so early in the season too!

Edited April 9, 2012 by Supacell

[Lauren]

Excuse me storms,

Be a dear and happen after work and at the weekends so I get to appreciate you fully instead of being in work.

Ta.

[Stuart]

Slight

Affected: SLGT: Most of the United Kingdom, excluding the far N + NE Scotland, and Northern Isles.

Synopsis:

Upper trough continues to slowly migrate eastwards with cold mid-levels overspreading areas of interest. Numerous showers and a few thunderstorms will develop as a result.

Discussion:

Cold-mid levels associated with a sharp upper trough overspreading warm SSTs and rising LSTs will result in steepening lapse rates and several hundred J/kg CAPE (potentially >500J/kg in places). Consequently scattered showers will be present over many western open waters at dawn, quickly developing inland as temperatures rise. Give ELTs as low as -45C locally, several showers are likely to contain thunder and lightning, with the best potential of this occuring over the eastern half of Ireland and across the Irish Sea into SW Scotland, NW England and N Wales.

Lack of any noteworthy shear will result in poor organisation of such showers and thunderstorms, and thus sferic activity may be fairly sporadic. There are indications of >20kts LLS to develop over N England and SE Scotland during the afternoon, and so here perhaps there exists the best potential for showers/storms to maintain their activity.

A dry surface layer will inhbit the depth of convection somewhat, with many showers forming in the mid-levels rather than being surface-based. This, combined with the lack of shear, will also inhibit severe weather. Hail >1cm is possible locally in any stronger cells.

Generally, showers will decrease rapidly in coverage during the evening hours as LSTs fall rapidly, but the presence of the upper trough over eastern Britain may allow some showers to continue during the first part of the night. Either way, showers will continue over the North Sea with the continued likelihood of lightning activity at times through Tuesday night.

http://www.ukasf.co.uk/storm-forecasts/148

[Supacell]

Excuse me storms, Be a dear and happen after work and at the weekends so I get to appreciate you fully instead of being in work. Ta.

Ha ha, i second this. Do you think if we get a petition going then mother nature may listen?

BBC weather says don't be surprised to hear a few rumbles of thunder tonight, i will have one ear to the window.

[Liam J]

Some pretty intense rainfall in the last hour, I was expecting a rumble or a flash but it didn't happen..... Plenty of convective potential during the next few days

Edited April 9, 2012 by Liam J

[Nick F]

Have issued a storm forecast for Tuesday:

http://www.netweather.tv/index.cgi?action=convective;sess=

looking a pretty active week convective-wise, which makes a very pleasant change!

[Raidan]

Sunshine and showers here at the moment,hoping mother nature will throw in a bit more as the day goes on,good luck everyone

[Coast]

Here we go for today, ESTOFEX have the UK under a forecast area, albeit slight:

Storm Forecast

Valid: Tue 10 Apr 2012 06:00 to Wed 11 Apr 2012 06:00 UTC

Issued: Mon 09 Apr 2012 14:57

Forecaster: KOROSEC

A level 1 was issued for southern France mainly for excessive convective rainfall, large hail, severe winds and lesser extend for a tornado threat.

SYNOPSIS

A large long-wave trough establishing into west-central Europe on Tuesday, where a strong cold front is pushed across France during the forecast period. A secondary low forms over NW Mediterranean and translates towards Liguria by Wednesday morning. Another trough/low slowly ejects SE Europe into Turkey. There, some convective activity will continue along the upper low and will exit our forecast area towards east later on.

A little bit of a chance in the West to start this afternoon?

Moving East later on?

[vortex_liam]

I can see some isolated showers turning heavy later on today moving east!