Joe Levy

Actually the key period of cold weather we are all looking for hasn't yet arrived. Currently the pattern is a bit further east, but still on track to provide a northerly. Never assume that silence is a bad thing!

Far from mild. Polar maritime maybe, but definitely not mild. Besides, I don't want to focus on the detail at t240 as that is FI! The overall pattern has a lot of potential and that is what I am looking for - potential.

Great t240 chart from the ECM 12z. It also leaves the potential for a bit more longevity to any cold that would come out of this, due to the low off the eastern seaboard, as TSNWK pointed out. Only a chance, and still in FI, but these charts have to start somewhere!

Don't comment on a chart before it has even been released. This doesn't look like a sinker to me, but that's just my interpretation

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=189&y=179 (South-West England) http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=236&y=3 (Northern England) The 12z GEFS set is out and is quite a lot colder than the 6z, with more runs going for a cold northerly some time from the 3rd/4th/5th for a few days from there. The greatest disagreement comes after then, as some runs bring back a more mobile flow, whilst others keep the northerly or a colder flow for a little longer.

Another lovely ensemble mean for the 12z gefs at t240, with the -4 line reaching the south coast

They are more than decent! They're pretty exceptionally low uppers at times and on that run it stays cold from about the 14th through to the 26th!

I am with you on this one, though levels of excitement are moderated by what we expect from our specific regions! For example, the output from the last 24 hours has been promising for cold and snow if you live in Northern England or Scotland, or a locality at elevation. However, some areas will almost always be marginal for snow. Living in Exeter, where cold and snow are rare, I am just happy to have the cold weather, though ideally I would prefer there to be snow as well! Some of the charts (especially on the 18z and 0z ensembles) have shown the chance of significant snow nationwide and so whilst some might almost expect that from a cold spell because their location is more fortunate, for some, the mere chance is more than is often encountered! Therefore, I am excited that we have cold weather now and that there is the chance of more cold weather and possibly snow to come!

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=189&y=177 (South-West England) http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=244&y=6 (Northern England) Not quite as cold ens as the 0z, but fluctuations are to be expected as the models grapple with varying degrees of amplification. It is also worth bearing in mind that all the GEFS sets were cold yesterday, so this could be an anomaly, however it's probably just within the natural variation that the models are showing at the moment.

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=190&y=179 Exeter ensembles. Other than a freakish technical fault showing temperatures plummeting off the edge of my computer screen, the ens are slowly clustering towards the colder side of the spectrum, which is good. Not only are we getting colder runs, but now we have a bit more agreement as well which is always helpful. But still, it's in FI and is a trend that needs watching

This set does not disappoint! Continuing on the theme of the 6z and 12z, the ensemble mean 850hpa temps show the -4 line reaching the Bristol Channel again!

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=188&y=178 Another cold set here for Exeter, even colder than the 6z at times. http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=238&y=2 Once again the pattern is even more marked in the North. One of the coldest sets I've seen this season so far.

Otherwise known as sod's law...

Just thought I'd capture this moment - the ensemble mean takes the -4 line down to the Bristol Channel! So this set is potentially even colder than the 6z. Exciting to watch, but still very deep in FI

Quite a nice looking ensemble mean for t240

Not sure it would be that marginal in the south. I've seen snow in the south in uppers much higher than are being shown there. These charts are for early December, so it's not like the time of year is against us in this case. Besides, let's get the pattern in first before we start deciding where is going to get snow The synoptics on the 12z are pretty great for the whole country if you like cold and snow

This is exactly the sort of chart us coldies are looking for! It does go well with numerous ensembles from the 6z set. Let's see how this fits with the other models And if we have a look at the NH view, the PV is very much reduced in strength and a large high cuts right across the Arctic

The gfs 12z is emerging, all eyes on the charts folks! If it's a good one, don't go over the top, if it's a bad one, remember it's just one run!

Also it's worth noting that on that set of ens, even though many runs do turn mild at some point, the majority also turn cold at some point as well, it's just that they're not synchronised, so whilst one run might show cold earlier on, another shows it later. I suppose this raises an important point about how we read the ensembles - a broad spread of runs doesn't always mean disagreement on the type of weather, it can often mean disagreement on precisely when different types of weather are likely to occur!

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=189&y=176 Bearing in mind that these ensembles are for Exeter, this is a pretty chilly set! This is for Northern England http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=252&y=2 I think it speaks for itself!

I am a cold lover and I don't feel my optimism is being drowned. The posts on this page by Summer Sun are purely observational! The model output tonight has plenty to cheer us up with by ourselves, without relying on others to fuel or ruin our optimism!

My favourite chart of this GFS 12z run, though it is FI

That's yesterday's run. Though today's 1 month run still has some good opportunities for cold in the not too distant future.

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=188&y=175 The ens for Exeter. Again, a very large spread, but interestingly, a cluster of about 5 very cold runs and another couple of quite cold runs, especially bearing in mind that this is for a South-Western location. http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=245&y=3 For Northern England this is even more marked. Nothing specific should be inferred from this, as it is only one set of ens, but it is good reason for coldies not to give up hope and further reason for us to continue to scrutinise the models carefully as they interpret changing patterns and data.

A very large spread on the ens - this is for Central Southern England, just as a random location that I chose http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=271&y=122 EDIT ahh Mucka you got there first!