New thread - Have we ever had a Part II before?

Looking Thundery in the SE at the weekend... maybe..

More likely a hit and miss type this weekend as usual.

Incredibly the rain managed to split just before the IOW last night and went east and west of us again - just a few spots on the ground and no more.
Still waiting for the first storm in years here - maybe the weekend but no time to look in detail today.

http://www.wetterzentrale.de/pics/brack2.gif

http://www.wetterzentrale.de/pics/brack2a.gif

An upgrade for Saturday night with the low a bit further west along with the 564 dam line.

GFS 6z has the thunderdy low splitting just before it hits me so I end up with nothing, as usual.

I suspect it will end up a bit further east than the models currently show, as is often the cause with storms coming up from France.

Heavy downpour in progress here!

NAE update. First signs of Saturday evening's/night's thundery low - http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=nae&MODELLTYP=1&BASE=201307251200&VAR=prec&HH=48&ARCHIV=0&PANEL=0&ZOOM=1&PERIOD=

Looks to be further west than the Met Office warnings suggest to me.

Estofex have issued a level 1 warning for SE England in their extended forecast for Saturday.

http://www.estofex.org/

I have pasted their summary below, but a longer discussion is available in the above link.

----------------------------

... An outbreak of severe storms is expected across France, the Benelux countries and northwestern Germany...

A level 2 was issued across parts of France, the Benelux countries and northwestern Germany for severe winds and large or very large hail, excessive precipitation and tornadoes.

A level 1 was issued across a larger part of France, the Benelux countries, northwest Germany as well as southeast England, parts of Denmark and north Spain for the same risks. 

This evening is a good example of how rain moving in from the Bay of Biscay can rapidy electrify as it hits France. 

http://www.blitzortung.org/Webpages/index.php

http://www.meteox.co.uk/h.aspx?r=&jaar=-3&soort=loop1uur&lightning=1

http://www.wetterzentrale.de/pics/D2u.html

Show nicely of the supercell over SW France.

Looks like the Isle of Wight, Hampshire and Berkshire are going to get rather wet in every sense of the word come Saturday afternoon/evening going by the NAE, Kent is still set to get a drop of the hard stuff as well.
  However, the NAE's output is at odds with GFS and even NAVGEM as the latter two has everything shunted further to the east.
  So it does seem that there is still much uncertainty as far as rain amounts and positioning are concerned, not to mention NAE's habit of suddenly downgrading things at the last minute. Such as is mesoscale-type modelling as it is trying to get to grips with what is quite a complex system.
  But either-or, it is still going to turn wet for a time over the South East and there are still plenty to keep an eye on where the proof will be in the pudding by tomorrow afternoon

Going by the ESTOFEX outlook, this afternoon looks to be quite extreme over NE France so we might get a good look at that one and who knows, it might even clip the far SE (hence the Lvl 1 warning being very close to there):

"An high-end level-2 situation however is forecast over NE France during the afternoon and evening hours. GFS and EZ both agree in the development of a plume with very high CAPE on the order of 2000 to 3000 J/kg. Similar shear (speed and directional) is forecast as described above, which is supportive of long-lived and well organized supercells. Current thinking is that either initiation due to a breaking cap (either due to diabatic heating or constant BL moisture increase) or southbound moving outflow boundaries from Belgium result in isolated thunderstorm development over NE-France. Expect explosive development with any cell, which experiences an uncontaminated inflow of very moist and unstable air. Large to very large hail (hail diameter in excess of 5 cm), severe to damaging wind gusts, excessive rainfall amounts and an isolated tornado threat exist with those storms. Despite a SW-erly steering flow regime, deviant storm motion should bring those storms near Paris-Nancy and Luxembourg / S-Belgium."

http://estofex.org/

One day we'll have a supercell crossing the Channel. I wonder to what extent such a storm could survive on an inflow channel, combatting the 15°C SSTs? It would need to draw in from the S or SE of course. Not sure why I bother with such theoretical thinking - they always end up going NE and clipping the SE at best

Met Office forecasts for Saturday now saying heavy and thundery rain rather than thunderstorms....

They never like to use thunderstorms so quality forecasting wording had been downhill very badly now.

I don't quite understand the issue with the term 'thundery rain'. IMO it adequately describes a more general area of ppn with embedded thunderstorms associated with a thundery low rather than discrete single of MCS cells more typical of a trough or imports.
NAE has an arc of intense ppn across C S up into EA Sat evening.

Latest NAE coming in shifts the heaviest rain back toward the south east with areas around the Isle of Wight also getting a soaking - http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=nae&MODELLTYP=1&BASE=201307260600&VAR=prec&HH=39&ZOOM=1&ARCHIV=0&RES=0&WMO=&PERIOD=

It never happened here as it only came up as general rains so this weekend is a hit and miss type that some areas will miss out and some areas will get it hard.