Harry

Certainly a lot more activity than the SPC forecast suggested. Cap appears to have broken not too far from you so here's hoping Edit - by not too far, I mean New Mexico which on Blitzortung looks a lot nearer than the several hundred miles away it actually is

Yup, it was 2008 apologies. Storms rolled on through for a good 4 hours with some very frequent lightning at times - during its peak it was flashing every 2-3 seconds. MetO just issued a wind advisory for the SE associated with the anticipated squall...nice!

Good shouts Meso and Rain123 - 17th/18th July last year, 28th June 2011(don't recall 2009) and 6th August 2006 definitely memorable for me Last year being an exception (which was a fantastic year in my neck of the woods) the fact that only 3 or 4 dates stand out over the best part of a decade shows how shocking times have been. Let's hope this year is a continuation of last

I'm quite drawn to the cell currently east of Snyder. The most isolated of the cells in their vicinity with an uninterrupted feed of heat and moisture and perhaps the most chance of becoming a right mover, particularly if influenced by the chain of storms the team are currently under. Furthermore if memory serves me well its closest to the SPC enhanced zone too. Albeit with my relatively novice US chase experience that's where I would target right now, also with a view that if it doesn't do the business it could be a good position to intercept storms approaching from the west a bit later

Deeply suspicious at the moment - ECM looking fairly good however GFS takes a different approach with a draw of fairly warm air however a fairly strong HP slap bang over us deflecting any real instability away to our South. Far too early to call a week in advance however signs are pointing to a much warmer and continental pattern later next week which is always a step in the right direction If however as you say the ECM synoptics prevail my money would be a on a fairly widespread and significant thundery outbreak - the evolution of that set up is for a low to spin up which, if the nicely aligned jet came into play we could be talking some severe stuff in the mix over possibly a few days...all to play for

The cell the team are bearing down on appears to show signs of rotation on radar (to my eyes anyway). Not even severe warned judging by lack of an orange box. I do wonder however how well it will hold up with the rampant cells to its South...time will tell but it looks the most tornadic to me at this current moment

I did wonder - tomorrow afternoon looks especially interesting with a very active looking squall sweeping through most of southern and eastern England. Low level instability appears marginal however the forcing of the front could be sufficient to generate some electrical activity I feel, as well as some locally notable wind events. I'm looking forward to it as squalls this time of year tend to bring dramatic skies and locally severe conditions...always a giggle UKMO rainfall forecast picking out detailed wavey squall pattern, which is the first time I think I've seen that in a chart.

Agreed, was awesome...paid for it today as have been a little tired. At one point you guys were away off to the right (as I was viewing) and I thought I could see a tornado way off in the distance...I was tilting my screen back and forth to work out if it was a distortion of the light - then I saw you race back over, pointing that way jubilantly (so am guessing it was!). Just in the 90 odd minutes I was watching there were (at least) three tornadoes I saw...was absolutely fantastic to watch...just a shame there can't be any sound

Well...that's three tornadoes from the same storm in around 90 mins that I've seen - awesome job chaps!! Must go to bed now (to my dismay!) - look forward to the highlights tomorrow

Nice to see my memory is in reasonable working order

I can't believe it - they had gorgeous open fields, decide to move along to a place with a crap view and it drops a stove pipe borderline wedge...fickle sods these supercells...well done team, and it's the first time I've seen one on the live feed

I may be wrong but I thought 2012 supercell day saw CAPE in excess of 2000, perhaps even nearer 3000. I can't be sure, however I seem to recall that day being one of those "oh yeah we wish" scenarios 7 days out, but never dropping away significantly as the day drew closer and closer. Even on the day I seem to recall CAPE charts with deep oranges and reds slapped all over it with LIs in the order of -7/-8. I remember it as we had those conditions with very high temps and dew points, but equally obscene levels of CIN so didn't manage so much as a dinky Cu out of it.Be good if there were some archived charts

Was looking so promising when I left the live feed and went to bed. The cell you were under had a gorgeous inflow band and did seem to show signs of some rotation. I went to sleep thinking you had it nailed...

Indeed, unfortunately (or fortunately depending on your persuasion to such things) synoptics seldom all overlay - when we have CAPE up in the thousands, its often due to a HP to our E, but with the jet way off to the north, or, with the jet running roughly the same direction as to low level winds (i.e strong southerly breeze at low/mid levels, with the jet also aligned roughly S-N)...its quite rare to have a SW-NE/W-E jet and a S/SE flow bring high temps/humidity...agreed it does happen, but I can't recall many occasions where this has materialised...when it does, like it did in 2012, we'll certainly know about it.

Yes, I saw this...what on Earth is going on?? A depression like that this time of year is not great news...the anticyclonic pattern building in after though looks better, which should give way to the East based on current models which may allow a brief plume. Equally, there may be brief import of some relatively warm/humid air ahead of that depression, but timing as ever will be crucial.

Of course, however the hail would be a pretty nailed on feature as well as potential straight line winds/down bursts...which wouldn't do my roof many favours lol. I remember it well - 34C here in the SE with very high humidity (not so much as a pinhead of precipitation to show for it) - the ingredients were all there for a 'significant outbreak' bar perhaps (if memory serves well) a particularly strong jet (although there was some jet activity) - this is the thing we often lack when we have heat and humidity and modest capping. The best thing was seeing on loop, the cells erupting over Wales (earlier than we'd all thought) and racing NE, followed by a succession of explosive developments over the Midlands throughout the afternoon.

Couldn't agree more - I don't mind chasing supercells across the plains of the US, but the thought of a funnel or golf ball sized hail landing on my house isn't fun! A nice MCS ticks my boxes...nothing severe necessarily, just some frequent lightning and booming thunder and I'm more than satisfied.

Tragically too far away at the moment...I'd take 500-600 CAPE with LIs of -2 given how poor this year has been so far. Plus I'm off to Greece for just over a week in Mid June so will be a little upset if I miss the first proper plume of 2015!

Think it's safe to conclude today was a bust

Clouded over here now, still warm but cooler breeze picking up.

Aye, agreed. Little cumulus overhead moving along at a snail's pace. Feels like a downpour is in the offering but some forecasts on TV seem unconvinced.

Had some good sunshine and heating here so far today...humidity feels ok too. Couple of ingredients therefore seem to be in place which is positive...now some lift!

Not at all - it's a Convergence Zone, where winds blow towards each other and collide. If you look at the charts above posted by Surrey, you can see the lines colliding in the areas I mentioned above, roughly along the Norfolk, Suffolk, Essex coastlines. It is not a classic CZ as the wind flow is not hitting full in the face (ie winds from the west colliding with winds from the east) but it just might be enough the force the air upwards to form some showers. There are other examples on those charts of CZs (see across the SW and NE of England), however the only realistic chance of any storms today is across the SE quarter.

This forecast is from Dan at Convective Weather UK: Day 1 Convective Outlook VALID 06:00 UTC Fri 22 May 2015 - 05:59 UTC Sat 23 May 2015 ISSUED 23:17 UTC Thu 21 May 2015 ISSUED BY: Dan Some marginal instability on Friday afternoon/evening as a warm, moist surface airmass destabilises in response to diurnal heating and wind convergence. Scope for a few showers and isolated thunderstorms given instability at both surface and in the mid-levels. Shear is very weak, with only marginal CAPE, so likely to be fairly isolated and disorganised if anything does develop. Main threat, given high PWAT and slow shower/storm motion, would be from locally large rainfall totals. On the 00z GFS charts a CZ persists for a number of hours in a line roughly from Great Yarmouth, through Ipswich, Southend and into the Medway area, perhaps extending as far south Sevenoaks/Tonbridge area. Conversely precipitation breaks out further west as discrete cells rather than CZ activity. Interesting.

Nope - estofex going down this time of year is not helpful. Still some opportunity tomorrow evening in the SE - UKMO and GFS still pointing towards something heavy breaking out but I'm not sure about electrical activity...look forward to reading people's thoughts tomorrow