Shiny_Bottom_1

Well...forgot to save to the desktop, then couldnt use the full editor. Anyway...

Hi Ian. I would agree with that analogy. GEFS Air Pressure Ensembles for Derbyshire: Shows really the scope of differences just from this model in the short term, and also the mid to long term. There are still some favourable GEFS members. I would say that the average is quite a plausable compromise at the moment.

Certainly worth having a look at the NW Model Comparison Charts for the 00z runs of the three main models -> http://www.netweather.tv/index.cgi?action=modelcomp;sess= Up to T+120 Sea Level Pressures are pretty similar H500 charts are similar* Northern Hemisphere H500 charts are similar* *It is worth noting though, that whilst the pattern is similar, there are some very very minor differences. GFS and ECM sit on either side of the fence, with the UKMO somewhere in the middle. All are good, but worth perhaps looking at.

Hi Paul. Temps have increased a little here to +1.5oC (dont know the min), and the frost is melting. The fog is starting to drop again here though.

OK, includes some of yesterday. However... During the sunset process yesterday, temps dropped off quite noticeably. By about 7pm, fog formed, and was fairly thick by 10pm. However, this morning, the fog has disappeared, and we have quite a decent (for the current season so far) frost.

Lets not forgetting whilst looking at the models, that the GFS is still prone to wobbles, but just as much as any other model. The ECM has never been 100% accurate (although typically the most accurate), but one scenario predicted in the mid term incorrectly does not tarnish its creditability. Lets just hope we keep a level head when the model forecasts are the other way around. For me, ECM is an improvement, and GEFS Ensembles still looking good. However, the later looks a tad (2m temp) warmer (but the outcome is still cold) than previous runs. The GEFS op run is also falling in line with the rest of the members on ppn, with no real wild outputs this morning. Also comments about not getting to work due to snow on Monday, on a previous page, would be unlikely. As above, the ppn is low, so no blizzards or drifts on Monday i'm afraid. There is certainly some changes this morning, but nothing to worry about, and nothing that again could not change back/further.

Again, just to pick up on the ppn/snow that people have mentioned on the GFS op run. The below is the 12z ppn charts for Derbyshire: The op run seems to be giving good ppn amounts, and has done over the last few days. But, looking at the ensembles, it is seen that it looks quite low ppn as a concensus. This, I would say, is why other models are perhaps not a snowy. Its not the GFS vs. others, its the GFS op run vs. the others. Get the cold first, then worry about the ppn.

Would agree with Ian on this one, re: snowfall. GEFS ensembles for PPN (taking Deryshire, E. Sussex and Kent) are all very low. One or two members going for 'something' but overall, looking quite dry (btw, op run is, whilst not what I would call an outlier, in general, is rather optimisitc in terms of rainfall).

Interesting that no-one seems to want to wait for the ensembles before making judgement Whether ECM jumps on board or not, we have seen both situations occur. I mentioned the other day that in the mid to long range it is an idea to watch correlation on the Air Pressure ensembles, which to be fair, have been quite scattered over the recent days.

Hi Paul. Is there any chance of adding the GFS 30 year mean to the GEFS ensembles (or GEFS 30 year mean, although I guess the same)- Or would it just clutter everything up (not sure what it would look like)?

Agree with Eugene, Badboy. It is not showing anything that wasn't already being projected by the big models. Some advice on viewing the ensembles when watching for this potential cold spell. Those who read my posts know that I don't dismiss FI. In fact, I don't buy in to the term...I just see it as a probability chart. Anyway, mid to long term, which is the time frame we are looking at, the key is to ignore the 850's/2m temps for the moment. Focus on the pressure ensembles, as these will give the best accuracy of all in terms of what we are looking for. We know that the high pressure will be close by, potentially feeding us the cold air. Position, orientation, and shape of this high are going to be crucial. If you see the pressure ensembles start agreeing more in terms of pressure rise, it is the first key. As this moves more from long range into the mid range (lets say for example, T+120-T+240) then start to look more so at the 850's, but keep a close eye still on the air pressure. We need the agreement here first before making judgement on whether the cold will hit us or not. You then need air pressure and 850's starting to agree in the above time frame to increase the probability, and then as you get in to the <T+120 time frame, detail can then start to be analysed with more confidence. Then, if you want to look for snow (you need the cold first remember!), then I would advise the best time frame to make a judgement on that is <T+96. Those who have seen the 00z air pressure ensembles from the GEFS will see that the agreement is not there for a pressure rise. However, there is also not an agreement on the pressure to remain low. Its quite a scatter this morning, which when looking at the potential both systematically and from a probability point of view, I would still not give any confidence that it will go either way at the moment. Previous runs have shown the potential, which should offer some hope. Either way, some warmer weather on the way next week. No what we want, but time frame left for wintry weather is so long, its not really worth worrying about. Thanks Nick. Quite amazing how many, whilst not over the UK, have the cold weather (-6oC Isotherm) not a million miles away.

But... ...if you look at it logically and rationally, a discussion can still be had. I discuss both short, mid and long term with the models. But if you view it correctly, you can make some decenet considerations for the mid to long term. The fact is it is part of the model run, so there is no reason not to discuss it. A sperate thread would mean, if you don't want to comment, then you don't have to post (but this could be said about the general thread anyway).

Hi Paul. I personally think this is a good idea, and one you have done before (or at least along the lines of). Quite a few dismiss the mid to long range input, and it is quite difficult to have a constructive discussion on this quite a lot of the time.

Indeed Frosty. I did write quite a lengthy analysis (for me anyway) for the 06z. Generally, I would say some good potential for the pressure to increase from week 1 to week 2. 850's are a little over the place in the same period, but 2m temps look like falling in line with the pressure rise (so would assume based mainly either average to below average 850's, or inversion with the high pressure even with above average 850's (I think inversion is the correct word - where high pressure creates below average 2m temps (December 2008?))

The thing is though, put yourself in their shoes. They've looked at the data, and they feel that there is a approximate 1/3 chance of all three happening. Is what they've put not the correct way of publishing this data, and its actually our perception and interpretation that is what makes it vague?

I saw my first snow shower yesterday...althought to be fair, I was about 350 miles east of here.

I think you've missed the obvious potential headline... ..."Met Office increase chance of colder winter from 1 in 7 to 1 in 5"

Are the GEFS ensembles still catching up?

What I would say, looking at thye pictures on the BBC, is if it were a Tornado, wouldnt the contents of the garage where the wall collapsed (and the bins in some of the pictures) have been disturbed? Looks perhaps more like some strong winds and heavy rain causing damage on perhaps some weak structure?

Well, I dont live that far away, but have to admit, I didnt see anything unusual here. We've had the odd strong gust today (like quite a few places), and the odd squally shower (like quite a few places), but no Tornado's. Saying that, Littleover build quality is not very good Mind you, Mrs SB1 genuinely woke up in the night thinking she heard an explosion. Fortunately, I just told her it was the*/my* wind. *Delete as applicable

Yep. Remember driving down to London in the evening when we got the bad weather. Was raining at home, but by the time I got about 15-20 miles south on the M1, it turned to sleet, and then snow about 5 miles further. I then had to drive from Leicester Forest East to just north of Luton with the snow settling on the M1. Was not the most enjoyable evening of driving, but a lovely site (at 20-30mph) nonetheless.

Hi Paul. Didn't you use to have the 14 day forecasts for some European cities on the site? Just wondering whether those in the GEFS ensembles (specifically Copenhagen as an example), can be transferred to the forecast format? Thanks. Chris

Maybe he was expecting a bed-wetting, flatulent episode

1947? The year my old man was born. Looking forward to the forecast!

Found this... Unlike Piers, I won't say he'll be wrong (unlike his comments about the METO...nice one Mystic Meg!). Anyway, issued in July, but who cares. All I can say is, he could have at least had a haircut, and done both his shirt button and tie up properly.