john w

On how much rain...check the relevant charts. On tides. We are just past the neap tides heading towards spring tides as we approach full moon. However around the british isles due to various factors there is a bit of lag. So fortunatelt at present tides are towards the lower rather than upper end of the natural spectrum. Of concern is now how full various aquifers are and the baseflow and saturated overland flow now likely to just exacerbate the situation in the thames. Rain now is the primary concern. Although both sytems have potential for damaging gusts.

Hey, Generally, friction becomes more dominant at the surface whereas the pressure gradient force and coriolis effect tend to balance each other out aloft. Now of course you get rising and falling air etc etc, so air will always converge towards the low centre and diverge from the high centre, but crossing of isobars is more pronounced at the surface. Make sense?

Few random street lights seem to be out. Wobbling in the wind no doubt. Heard some glass smash in the distance, either that or a metal plate crashed in to something. Another 1-2 hours of this and any squall is we get them here. I just hope many of the old oaks in this bit of town survive yet another storm!

The weather has really picked up wind wise here. For those pondering EIN724 went around, was diverted to the Ockham hold, they considered their options then returned to cork. Im hoping this passes without causing too much chaos to the trains, but this seems unlikely for those poor people who need them tomorrow!

It is full of trees I can confirm

http://www.environment-agency.gov.uk/homeandleisure/floods/riverlevels/ knew it was in the public domain somewhere.

There used to be a decent site that had flood stage for streams and then reported against stage boards, but cant remember it. They don't do hydrometrey here like they do in the US...but stream UNDER her kitchen. I assume its in a culvert and they have not just built a kitchen over a stream?

If that's the case, I would say a shade deeper than what models predicted. I caveat very heavily that I do not know how this chart you posted models the isobars. See a previous post I made, but at 00:00 most models went for about 985 around Bristol

Imj not sure why everyone else has missed this point apart from us, the meto Amber doesn't kick in till 00:05!

Things still in the Bristol channel, best yet to come

quite

To put it in to context Bristol Metar at 22:50 was 989 At midnight the 18z NAE expects between 986 and 984 (lets go for 985) The GFS expects between 986 and 985 The UK met expected (based on their 12z) about 985 The GME - about 986 The GEM - a shade below 985 perhaps (based on 12z). So if something concerning in terms of cyclogenesis is concerning, we can use model runs to compare to the nowcast. And as the models show, some fair drops in pressure in a shortish space in time are predicted too. So google Bristol Metar, sit and watch, and take a peek at 23:50

Depends what you mean, concerned in the context of what is predicted by the met office, then yes, these will bring conditions similar to what has been predicted by the various models. Concerned that these show something occurring that is beyond the scope of what models have predicted thus far. No.

Sterling effort John thanks. GFS has this moving through, based on a crude analysis of the 12z NAE and GFS, around 3 hours more quickly than the NAE and as a shallower feature, albeit the NAE went for it being slightly south (though on accuracy and error parameters I would have called the difference insignificant). A Bristol midnight pressure reading will be perfect for comparisons on GFZ, ECM, METO and NAE 12z+12, 18z + 6 (for those 18z producers). As for conditions in Bracknell, rain, warm, wind, 2 of the Beaufort Scale.

If id have been picky...id have also said that tends only to be true for closed circulations....but we shant go down that road and in essence, it can also occur before open circulations, but not so much as in the true sense of the word anyway!

Thanks John. I have tried to find a decent pressure readings (as in live) chart, compared to jet which is, as ever, ever evolving. Cant help but think this is going to really come down to positions of the surface and the aloft features working harmoniously, else intensification or 'turbo storm' or whatever the new term is...takes effect. Nothing like the good old days of learning. The surface low feature needs to be below (relative) to an upper area of divergence to continue cyclogeneis....in pure traditional meteorology anyway.

The fact of the matter is, worst winds even for the south coast are not expected for a while yet. The media and people need to realise this. Incidentally John H or Ian F, is there anything yet on how the genesis of the low is doing compared to the jet position? As that is what is fundamental to the intensification of this storm.

1 of 2 things, As there will be cross winds, there will inevitably be more go arounds and so there could be more chance of a hold and/or even for their flight a go-around, albeit larger planes handle cross winds better than smaller ones. If it gets too congested or otherwise, the flight may consider flying to its alternate airport.

Nice chart, whats your source for the first one. I note its almost on a parallel (the low possible a smudging further north) than what the GFS 12z+3 shows: Await the 12z meto and ecm updates: NAE Whats interesting is the exit point and track and time. GFS has it heading in through the Bristol channel, on a bearing of appx 050-060 degrees to exit north of the Wash at a central pressure of 980. NAE has it a smidging further south and more inland at the same timestamp as above for the GFS Then exiting at roughly a similar position to the GFS, but lower central pressure at 972mb and 3 hours later (again possibly a smudging south, but not anything significant in terms of accuracy when comparing to the GFS). So effectively taking 3 hours longer to cross, but also arriving slightly later. I have to say if the GFS comes to be correct on timings, much of the main event will have disappeared by the time we wake up tomorrow to any damage cause. Whereas the NAE prolongs this further. Await ECM and UKMET, but this must be a forecasting nightmare, intensity of the depth is still being questioned by major models and exact track is still also up for some debate (albeit within a corridor that's probably not much more than 50 miles wide). For comparison,. the UK Met 00 Fax has the low in 8 hours time (e.g. midnight) somewhere in the Bristol Channel at a depth of 977 which compares to the GFS at 00:00 as 983mb and the NAE as 978 mb....all roughly in the Bristol channel or SW approaches to it. As for those harping on about the met office red warning being used. Take a look at the impact matrix, this has already been identified as a high impact event, the likelihood is the only parameter that needs to be made 'more certain' to trigger red warnings. So, unless the intensity goes along the line of the GFS and there is somehow a reduction in impact as a result, I would expect to see some red warnings as the certainty of this event becomes clearer. Stay safe! ARGHHH me charts haven't worked!

Well lots of rain so far, feel sorry for Woking/Weybridge areas, they wont even have had a heavy downburst yet. Nevertheless the shield should soon collapse. The rain will have cooled things down now, so I am not so optimistic for much electrical activity. lots of heavy rain to contend with and any rogue flashes and bangs that do occur will be a bonus. If I hear anything my way, ill now-cast and let ppl know. Biggest potential for my patch is that cell coming over Portsmouth now to contain something, but as stated, rain beforehand may have died down potential. For tomorrow my patch has low cape and uplift compared to other areas. The best one ever here still remains as per the link http://www.metoffice.gov.uk/climate/uk/interesting/may2000brackstorm.html They probably only wrote about it as they were based here at the time. But it was pretty epic!

Its showing 'some' potential to the south. Incredibly dark, would assume its cb-ish. Surprised there isn't more south-centralites in here...perhaps in regional threads.

Rain now commenced, am torn as to what to call these clouds as they honestly don't appear cb. Id say they now look more like stratus clouds. Really difficult to understand this setup I have to say, from viewing the radar and others posts I would expect towering cb and the odd rumble to be approaching by now. Anyone here from Reading/Basingstoke able to confirm what they are getting, as a shield seems to have placed itself over Bracknell/Guildford/Slough etc at the moment.

Hmm, just noticed with my window open in the sheer hope of hearing a distant rumble, Heathrow is on easterlies which means there must be at least a 5kt wind from the east (with an easterly component added in) (in line with their westerly preference rules), for them to be flying this. Of course that's at ground etc, but interesting all the same.

Those in East Berks...nothing to report, not even any rain yet. Clouds, presently cumulus and some high cirrus, would not call these cb. No wind and not too humid. Very odd!

Not sure why people believe the channel is killing the stuff about 50 miles to the south coast, raintoday seems to show it having moved preffy consistently so far. Once it hits the downs and you get the areas of uplift we shall see what happens. Seems to be more a north north east push now, even northerly dare I say it. The spread of activity inland (virtually due east) from Biscay over in to france is impressive (and I would add for anyone reading this...I mean the spread/development of activity in an easterly direction over france, not the movement of the general pattern which seems to be more north north east/north). In perspective, I would say that most of south east, central and west central England have a chance at decent precip amounts and rumbles of thunder now. Intensity, I will let more pro people comment on. Edit (forgot to say, look over Nates on raintoday to see the extent of the development of the system moving north/north north east off of Biscay...wow!)