VillagePlank

Yes, it's all gone a little quite. All waiting for the cap to break, the longer it holds off during prime heating hours, the better it will be - if you like this sort of thing, of course.

That MLCAPE needs to erode away ...

Wyoming has had a problem with the Herstmonceaux one the last few days - is there another source/link that's more reliable? I think UoW lost their disk drive ...

6z update for West Midlands ... Scattered thunderstorms are likely in a moderately convective environment (K = 34) Of those that form, it's highly likely that many of them will form severe characteristics (TT = 55, LI= -11) such as large hail and frequent lightning (CAPE = 3,944 J/kg) Cells that form may exhibit excessive precipitation (PW = 3.77) Convection is unlikely to get going full speed until later this afternoon, early evening, at approximately 6pm (CIN c.242 J/kg) although local orography may well kick of initiation before that. When convection does get going it may well form storms very rapidly indeed (LI = -11) Tornado development seems to be on the edge of likely/unlikely, and will almost certainly be a wait a see, although supercells are not ruled out given the rather remarkable convection parameters GFS has thrown out this morning. Happy Hunting (and take care) !!

Yes, sadly, even though the parameters for the SE for severe weather are exceptionally good there's a cap over the area for most of the day - perhaps, but unlikely, eroding by 6pm - which means no storms for us.

Today's hotspot, is Birmingham, and, pretty much all of the N Midlands. A moderately convective environment (KI = 27) may lead to widely scattered severe storms (TT = 53) A (very) large amount of energy becomes available (CAPE = 2,402 J/kg, Dp = 20.9) after being inhibited for most of the day (CIN = c.200 J/kg) in an extremely unstable profile (LI = -9) carries the risk of frequent lightning, and large hail. Any cells that form will also contain large amounts of precipitation. Happy hunting!

Today's hotspot is Cambridge and surrounding areas - particularly an area from Cardiff, through Cambridge out to the North Sea. Small convective potential (K=23) may lead to thunderstorms. Quite some energy is available (CAPE = 1314 J/Kg, Dp = 18.4) and with large instability (LI = -5) strong surface heating and a front stuck and occluding across the Midlands should lead to conditions for thunderstorm formation. Organisation does not look likely (SREH=27) Happy Hunting!

MetOffice have thunderstorms for Birmingham from 7pm to 10pm http://www.metoffice.gov.uk/public/weather/forecast/gcqdt4b2x#?date=2017-06-19

Ideally you need to the clouds to stay away to get maximum surface heating. Then .. ...

Sadly, I think anyone in that lighter blue in the South is going to be disappointed, today. Although, where this is marginal - clearly all the South can't all have exactly the same value - they might get a dew-point depression boost out of this.

There's always a chance, I suppose. However, the forecast is that convection looks highly unlikely (KI = 5) despite large quantities of CAPE - which look to be going to waste, today, in our region.

One other thing, if this CAPE is realised (there's always a question of this) then tornadic development may follow (EH = 5) although this seems unlikely given 1-3km shear not being sufficiently high enough for formation (SREH = 28)

Today's hotspot looks to be the Birmingham area, heading up towards Manchester. A moderately convective environment (KI = 26) may lead to thunderstorms (TT = 48) Plenty of energy around due to surface heating (CAPE = 1914J/kg, Dp = 20.8) with large instability (LI = -7) should lead to some storms forming. If and where these form, frequent lightning and moderate size hail may become an issue. That all said, there is a rather dry area aloft that may inhibit storm formation (RH < 45% @ 700hPa) Very strong surface heating should be able to overcome this. Happy Hunting!

Cambridge would be my hot spot tip, today, and surrounded areas, particularly to the East of Cambridge. This skew-T suggests moderate convective potential (K = 27) leading to chance of thunderstorms (TT = 44). Plenty of energy about (CAPE = 1352J/kg, Dp = 19.6) but with marginal instability (LI = -4) there is limited potential for them to fire up. Noteworthy that instability is at the very cusp of being better than marginal. Lucky to get one, but I reckon there will be one or two about. Happy hunting!

Don't forget that CAPE is all about that pesky theoretical parcel being warmer than the surrounding air at every atmopsheric level - CAPE of over 2,500 J/kg is considered extreme. In and of itself a forecast of high CAPE isn't necessarily an indicator of extreme weather, although, clearly, its very helpful as an indicator to look for other things; it's always worth remembering that this a theoretical value and it must be realised - worth looking at KI, and, perhaps, TT, to figure out whether it will be realised. In this case the KI on the skew-T above looks perhaps on the edge indicating a moderately convective environment.

That'll be what I just saw to my South-West: very impressive looking at it from a distance!

Spider-lightnng observed to my South-West: there is hope!!

Anywhere from St-Leonards round to Thanet looks ideal for tonights viewing, I reckon. I can hear the rumbling, but it's very distant flashes. I might have detected a veer slightly to the North, but it is late....

Bulk of the strikes now in the Dover Straits heading out up into the North Sea ...

Storm line seems to be slightly South of the VV chart - ie upward vertical motion, giving at nice pep up after it's channel crossing.

Looks to me as if this is going to end up primarily as an East-Kent clipper .... Here in Rochester, I might get lucky and get some of the western edge of it I suppose. Rain, some of it heavy, much more widespread, of course.

Rumbling heard here in North Kent. Most active part of the system is to the eastern edge moving in a NNE direction

Imports from France, not 'breaking out' - and it looks like they'll be an East Kent grazer at the minute.

Quick heads up for Saturday afternoon. Here's the skew -t It's for Heathrow on Saturday 12z. Oddles of CAPE (>1200) in a moderately convective atmosphere (LI=-5) with a slight cap at 850hPa (CIN=1) Other indices imply scattered thunderstorms (K=34) some of them severe (TT=51) giving well over an inch of rain where they form (PW=3.81) Dew points uncomfortably high (19.1) This is supported by a tongue of theta-e ridging up from the near continent into Central England for midday edging out NE during the afternoon, No systemic rainfall forecast - a weakening front approaching from the West, sadly weakening from the SE first, so triggers to be the main problem for thunderstorm activity. Some solid and strong late morning sunshine to early afternoon sunshine with convection inhibited at 850hPa (around the nominal cloud base) may be enough to set off some spectacularly quickly formed thunderstorms mid afternoon. Happy hunting!

The precipitation simply stays out on the North Sea. Here's the accumulated values (in mm) but if your read it x10 (so as cm) this is how much snow you can expect to be possibly be around your location by the end of Sunday