Uk Convective General Discussion & Forecasts, 15th June 2012>

[Eskimo]

Clouds also bubbling up here in North Herts.

[Evening thunder]

Hmm the latest BBC forecast's don't even mention anything to do with thunder, and the graphics just seem like more general rain rather than intense downpours... bl***dy typical!! If mid-level cloud can completely cloud over today (which was forecast to be sunny until yesterday afternoon) so I can't even get an average/above average max temp on supposedly 'the warmest day' of this diabolical month for warm weather, I'd like to get some of the thundery benefits from it that were suggested!

Just felt like I needed a little rant there..

Edited June 20, 2012 by Stormmad26

[Mapantz]

Sunny here, but some mid-level cloud, and even some cumulus popping up towards the north east of me. I should be in the thick of some action later, and i have no work tomorrow, so i will be up until at least 5am.

[Mesoscale]

Not gonna happen... we have seen this all to many times it looks good but nothing happens or if it does happen it will be very isolated making everyone but a few dissapointed! Good luck to those who do get something though but for the vast majority don't get too excited.

Edited June 20, 2012 by Mesoscale

[Supacell]

How about tomorrow, its looking good for something tomorrow even if tonight doesnt come off.

[Sprites]

I cant quote the exact post from page 18, as my phone cant handle the pics, coast said here are some pics to trace around and hang in the greenhouse or toilet, i put some in the fridge and loft , they look great!! , wet and cool tmrw outside chance of a rumble too.

[richep]

I'm prepared to sit up all night as long as theres a chance, no work tomorrow.. But will definately have to stay off the Thatchers if I stand any chance of staying awake.

[Mapantz]

Thunder or no thunder, i like torrential rains in this setup. Warm air pushing ahead of the low can really create some intense rainfall, and with PVA at vort-max, should be quite interesting.

[Mark Neal.]

Will be interesting to see, ahead of tonight's weather front, which will bring heavy & Torrential rain will there be some thunderstorms as temperatures are widely 18-22c and dew-points are reasonably high.

Edited June 20, 2012 by Mark 'Ox' Neal

[simonbiggs]

Seems alot of quick cloud development from Midlands, and South Eastwards.

Anything of interest?

http://www.sat24.com/en/gb

[Coast]

I cant quote the exact post from page 18, as my phone cant handle the pics, coast said here are some pics to trace around and hang in the greenhouse or toilet, i put some in the fridge and loft , they look great!!

Lets hope you have an opportunity to revisit them on occasions, to being back the thoughts of a memorable TStorm then!!!!

SkyWarn have a provisional forecast out and subject to it being approved by them and formally released, looks quite interesting:

SKYWARN UK SEVERE THUNDERSTORM WATCH #031

ISSUED: 1300UTC WEDNESDAY 20TH JUNE 2012 (GJ/GS)

SKYWARN UK HAS ISSUED A SEVERE THUNDERSTORM WATCH FOR THE FOLLOWING REGIONS:

WALES SOUTHWEST ENGLAND SOUTHERN ENGLAND SOUTHEAST ENGLAND MIDLANDS EAST ANGLIA NORTHERN ENGLAND

IN EFFECT FROM 1700UTC WEDNESDAY 20TH UNTIL 2100UTC THURSDAY 21ST JUNE 2012

SHALLOW LOW DEVELOPMENT TO THE WEST AND SOUTHWEST ENCOURAGING A WARM AND SATURATED PLUME FROM FRANCE, WITH EMBEDDED AND POST-FRONTAL INSTABILITY.

THERE IS A POSSIBILITY OF SEVERE WEATHER AFFECTING THE INDICATED REGIONS IN THE TIME PERIOD SPECIFIED. THREATS WITHIN THIS WATCH INCLUDE, BUT ARE NOT LIMITED TO: HEAVY RAIN... FLASH FLOODING... HAIL... LIGHTNING... FUNNELS/WEAK TORNADOES

DISCUSSION:

THERE IS GOOD MODEL AGREEMENT ON THE POTENTIAL FOR A SEVERE WEATHER RISK OVERNIGHT WEDNESDAY AND THROUGH THURSDAY. A CYCLONIC JET LIMB ROUNDING THE BASE OF THE PERSISTENT UPPER TROUGH WITH STRONG VORTICITY FOLLOWING ON WILL DEVELOP AN INITIALLY COMPLEX SURFACE LOW AREA OVER THE WEST AND SOUTHWEST OF THE UK. A PLUME OF HIGH THETA-E VALUES FROM NEARBY FRANCE WILL RESULT IN A DEVELOPING FRONT WITH EMBEDDED ELEVATED INSTABILITY PUSHING INTO THE SOUTH FROM THIS EVENING. PRECIPITABLE WATER VALUES OF AROUND 3CM ALONG WITH WELL-SHEARED CONVECTIVE ELEMENTS MAY RESULT IN HIGH RAIN RATES ACROSS THE SOUTHWEST OF ENGLAND AND WALES, AND ALSO THE SOUTHEAST OF ENGLAND INTO LATE THURSDAY MORNING THOUGH THE ENTIRE FRONTAL ZONE WILL HAVE THE POTENTIAL TO PRODUCE STRONG CONVECTION. ACCUMULATIONS OF OVER 20MM IN SHORT PERIODS MAY OCCUR, PROVIDING A RISK OF FLASH FLOODING AND EXCESS SURFACE WATER.

INTO THURSDAY AFTERNOON, THE FOLLOWING UPPER COLD POOL AND VORTICITY WILL ALSO GENERATE AN AREA OF STRONG CONVECTIVE DEVELOPMENT IN THE POST-FRONTAL ENVIRONMENT ACROSS THE MIDLANDS, WALES AND THE SOUTHWEST OF ENGLAND. THE COMPLEX SURFACE LOW PATTERN WILL CREATE ZONES OF SUPPORTIVE SHEAR AS WELL AS WITHIN THE STALLING FRONTAL ENVIRONMENT OVER NORTHERN ENGLAND. AS THE LOW CONSOLIDATES AND BEGINS TO DEEPEN, A SHARP DRY AIR INCURSION ALOFT WILL PUSH INTO THE SOUTHWEST POSSIBLY ENHANCING THE CONVECTIVE RISK AND GENERATING MODERATE HAIL SIZES AND FREQUENT LIGHTNING. ANY STRONG UPDRAFTS ATOP EASTERLY SURFACE FLOWS, OR IN LIEU OF TOPOGRAPHY, MAY HAVE THE POTENTIAL TO PRODUCE FUNNEL CLOUDS AND/OR WEAK TORNADOES. THIS WATCH MAY BE UPDATED OR UPGRADED. PLEASE MONITOR WEATHER AND TRAVEL INFO AS NECESSARY.

I hope this isn't embargoed, I might have to take it down if it is.

[Eskimo]

Lets hope you have an opportunity to revisit them on occasions, to being back the thoughts of a memorable TStorm then!!!!

SkyWarn have a provisional forecast out and subject to it being approved by them and formally released, looks quite interesting:

I hope this isn't embargoed, I might have to take it down if it is.

Considering its a warning for people which inevitably provides a heads up about whether there could be a risk of disruption/injury/death then it shouldn't really be embargoed in my opinion.

[Coast]

Considering its a warning for people which inevitably provides a heads up about whether there could be a risk of disruption/injury/death then it shouldn't really be embargoed in my opinion.

I really meant until they have formally added it to their warnings page. I think it's provisional at the moment.

[Eskimo]

I really meant until they have formally added it to their warnings page. I think it's provisional at the moment.

Ah I see okay

[Coast]

Finally got the 21st OWS charts for overnight, more intrigue and interest:

[Arnie Pie]

With tomorrows solstice dawn looking like a no show (hopefully obscured by thunder clouds)

I took the opportunity to 'bank' this mornings Sunrise over Birmingham city centre

Edited June 20, 2012 by Arnie Pie

[Thundery wintry showers]

I'm trying not to get too excited as it usually all goes pear shaped. But there is that 'heavy' smell of....of.....SOMETHING in the air. @TWS, hope you're enjoying you're stay in Norwich. and hope you get some East Anglian thunder.

I was in Norwich most of the time from September 2007 to June 2011 doing a PhD. I was aware that Norwich is traditionally one of the UK's thunder hotspots and 2008 and 2009 did not disappoint, both having thunder on approximately 16 days, but 2010 and 2011 were somewhat disappointing, particularly the first six months of 2011.

To be honest I hadn't even contemplated thunder in Norwich during my current stay (bar a couple of GFS runs that showed thundery showers for Friday about three days ago) but then was surprised by this morning's GFS outputs.

[Eskimo]

Couple of cells have popped up on the radar in the channel.

[Lewis]

That's not strictly true Lewis as the NMM MLCAPE chart I posted above shows a good finger of potential creeping up through my location and heading North at around 0400 hrs with 300 to 400 J/kg of energy and -1 Li. Not going to set the World alight but still not bad and just in the darkness hours. It might keep those druids on their toes!!!!

Hi Lewis....you're looking at the wrong CAPE charts to make that judgement mate...Any convection tonight is likely to be elevated in nature, and the MLCAPE (multi-layer or mixed layerl CAPE) and multi layer LI charts are very promising for a good swathe of central & southern UK....Not had chance to check the moisture profiles yet, so until I have a butchers at these, I can't comment on whether the profiles show saturation throughout the atmosphere (saturated profiles from my understanding would not be conducive to elevated storm development)

Hi guys sorry your both right, I failed to look at the ML CAPE & LI charts, I rarely look at them, when I do look at the MLCAPE & LI charts it's because there's a good amount of SBCAPE about, a fair number of times i've rarely seen some ML CAPE without some SB cape, tonight/tomorrow mornings scenario is entirely different and I was looking at the wrong charts

After looking at the MLCAPE charts and Lifted Index, there is sufficient energy though to produce elevated storms embedded in the system moving up during the early hours of tomorrow morning.

My apologies for misinforming people.

I'm storm chasing tomorrow if anyone want's to join me let me know just reply to this message, i'll be around East Yorkshire& N Lincolnshire, will pick up on the way.

Lewis

Edited June 20, 2012 by Storm Force Lewis

[Keraunic]

Re thunder in Norwich, the last really good one I remember was early hours of 13th September 2006 - drove through some lightning and distant rolls of thunder on way up to York just outside Norwich. Then drove into a corker in Norwich on way back that same evening.

[Andy Pepler]

it would be glastonbury weekend down here so someting has got to happen . or will it be sod's law and nothing will happen..oh well one thing is going to happen ..25,000 wet hippys plus me at stonehenge tonight ..lol ....but we do need a darn good storm ...so to the storm gods ..come on show us a good lightshow please..

[Lewis]

Tomorrow East Midlands, EA, Lincolnshire and Yorkshire will take a battering of some severe storms I reckon, just looking at the charts now, everything spot on, CAPE and LI (SB and ML) 850 lapse rates, temperatures, dew points around 16-17c! Looking sexier than a blonde on a night out.

Edited June 20, 2012 by Storm Force Lewis

[Coast]

[Team Jo]

Rod Stewart?!

[Andy Bown]

Very unstable mid-upper level cloud with a layer of Altocumulus (some Castellanus) covering much of the sky now and scattered

robust looking Cumulus beneath. Some much darker areas of cloud have moved North to the West of here in the last few hours.

It looks right, it feels right.