linarite

You're being ironic I hope

whatever the eventual outcome, i think the fact that these extremes are being modelled must concern us all. and there's also the interpolation/extrapolation problem. As we start stepping out into situations we've never seen in the parameter space, models become more and more unreliable. But that cuts both ways, and it could be even more extreme rather than less

potentially worrying amounts rain for NW England keep showing up in the later stages of high res GFS. On top of the c. 100mm forecast for next 5 days. We're still clearing up from December's sequence of frontal systems. I imagine the Met Office will be keeping a very close eye on this development.

Meanwhile, in the 6-day time-frame, the GFS12z is showing for North Wales an alarming total of 290mm of rainfall. This is the highest 144 hr total I can remember ever being shown by the GFS for England and Wales.

some rather nasty rainfall totals for NW England for the end of the week if the latest few GFS outputs are any guide.

agree - though tbh 23C would count as remarkable after the dross we've had in the NW since April

rainfall totals for Cumbria looking pretty grim too

I hope those pressures modelled on the 06z GFS para for wed/thur next week turn out to be wrong (935mb central pressure??!!). As currently shown this would be a catastrophic event

The GFS PARA models a quite extraordinarily severe event for 27th/28th, combined with a spring tide. We must hope for the sake of the north-east and east coast that this downgrades.

Warm maybe - dry..I think not!

absolutely agree about the dangers of trying to link one particular event, or one particular season's weather, to anthropogenic climate change. But you must surely accept the basic physics of the matter - Fourier and Tyndall worked out the essentials in the 19C and nobody, as far I know, has ever undermined the basic premise that increasing CO2 concentrations in the atmosphere increase the net amount of heat reaching the earth's surface. It is also indisputable that mankind's burning of fossil fuels has increased atmospheric CO2 to a level (400ppm) not seen on the planet for 3 million years, probably more. So given these two reasonably certain premises, it is not on the face of it unlikely that there will be effects on the climate system. Yes, of course there are natural climatic cycles driven by astronomic factors such as solar activity, and one-off effects resulting from volcanic activity etc etc, These are actually quite well understood because of the ice-core record, use of isotope climate proxies etc, but because we know there are natural cycles does not make it logical to assume that mankind's effects on the climate are not significant, can't add to, or even override, natural cycles. And , incidentally, scientists do not believe they are' beyond criticism' - the whole point of a scientific explanation for a phenomenon is that is only the best available explanation, but that the explanation ('model' whatever you want to call it ) is always provisional and open to revision. Scientists are never certain they are right (unlike some of the more vocal opponents of science).

It would be stupid if that is what the Met Office said, but what Dame Slingo actually said was "...all the evidence suggests there is a link to climate change." (my italics). Rather different. So if you are going to criticize, get your facts straight first.

Indeed this little storm is unusual in terms of position and intensity.. after giving Aquitaine a good seeing-to it looks like it will track NE, possibly bringing yet more rain to SE England. It wil be interesting to see how it's modelled in this evening's output

If there was a 'required reading list' for new members, this would have to be on it!

They say "Since the issue of this Alert yesterday, the probability of heavy rain appears to have decreased, and if this trend continues, the Alert could yet be removed"

Oh dear - the GFS is throwing out some rather 2011-like charts in FI

not so sure about 'little rainy'. Looks like a stalled front could bring significant rain to SW Scotland. Actually the synoptics on the GFS 12z for middle of next week are not a million miles from Nov 19/20 2009 - and we all know what happened then

See October 18 1991 and Oct 17 1992 in GFS Kartenarchiv. Very similar set-ups to what is forecast for later next week. I remember snow to low levels in Cumbria from the 92 event

Some pretty exceptional (for June) rainfall totals being modelled by the GFS00z for North Wales and the Lakes over the weekend

Re Thursday/Friday, Chris Fawkes gives a nice little video summary of the Met Office's view of the range of model uncertainty on the BBC weather page http://www.bbc.co.uk/weather/features/16165125

I'm surprised that nobody has commented on the way the GFS has been consistently modelling for some days now the possibility of intense and prolonged rainfall for NW England /North Wales next week. Even without the secondary low shown on the 06Z to hit around 162 hrs, rainfall totals could be prodigious between Tuesday 22 and Friday 25. Shades of the 19 Nov 2009 situation (and the charts are worryingly similar). Sorry mods if you feel this post belongs in another thread.

Laura Tobin really downplayed it on the lunchtime BBC weather. Said 'an inch or two'. Perhaps this means the Met Office don't think it will be too bad, but have used the warnings on their website just to cover themselves.

- exact amounts may not be too accurate at this range, but timing and length of wet spell has been progged consistently for several days now. It looks like between 24 and 30 hours of continuous rain for Cumbria. That's going to add up to around 5" over the fells from past experience.

yeh, you're quite right in a hundred year really mean a 1% chance per year. But point i'm making remains the same

Yep, very true - and I get annoyed too by the constant attribution of every weather event to GW. However if GW does manifest itself in a tangible way, then what we'll experience is 'weather'. Here in Cumbria we've now had a 100-year flood event and a 1000-year flood event within 5 years. I'm not saying its 100% certain that this is attributable to GW, but it's natural to start taking it as a serious possibility, and for people involved with flood risk management, it would irresponsible not to, wouldn't it?