We had a major tease from the models for a couple of days a fortnight ago which sort of came off, although we didn't get the strong height rises over the Greenland region that GFS and ECM in a few op runs had toyed with. Even though January will not go down as a classic for cold weather by any means, it has given us more of it than the pathetic month that was December ever came close to doing.

As I said this morning, we could by the end of January be seeing model runs that look rather better for cold fans, or maybe not. What doesn't seem to be in the offing as far as I can tell is a return to December's disastrous pattern, and thank goodness!

Why was the 18Z better? Let's take a look at the bigger picture at 234 hours (no prev button on NW for 240). 12Z left, 18Z right. 

Note how the jet buckles in alaska sending warm air torpedoing into the arctic and ultimately raising heights across greenland. Pale blues do wonders for us as opposed to dark blues and actually allow us a full on arctic feed (albeit from the north west). If this trend continues then things could improve quite rapidally. I consider the 552 line over Greenland to be the holy grail but even if we get the pale greens then there could be some degree of communication between alaska and the midatlantic via the arctic encouraging the azors high to relocate west. One to watch, note the low heights over scandanavia will help to facilitate such a process. 

I haven't posted in here in a few days because I couldn't find any optimism in the charts at all; finally I've found it.

Good post Q 

As GFS smells the coffee with respect to the tropical forcing, it should sharpen up the U.S. amplification and consequentially tend to have the Atlantic pattern a little further west (not much at all) and considerably better defined in terms of a mid-Atlantic ridge and Sceuro trough.

This may not happen smoothly though. Yet I believe it won't be too long now before lower-res GFS is showing us some tantalising charts... which, if things follow a typical path, will prove to be too simplistic, hence quick, with the actual path a bit slower but still getting there in the end.

Yeah, I've been through too many winters to be as much fun as I once was 

12Z ECM ensembles are very interesting. Since I'm not a met employer I can't see them, but I can infer there are some really bloody cold ones even before February.

Note the downward trend in the 850s even getting to about -5C by the 1st. However what is more interesting is the standard deviation. Weatheronline also provides a table which gives the standard deviation at the end of the run at about 3.7C and a mean of -5.1C. Now I'm going to assume guassian statistics here because a) I really have no choice given the limited information and b) random variables obey it anyway. 

Assuming the ECM has 50 ensembles (I think it does right?). At the end of the run for London:

25 are below -5C

5 are below -10C

1 is below -13C

I wonder where they source their data; the mean they give certainly doesn't match what can be seen on the Meteociel version of the day 10 mean chart, which has always seemed reliably correct to me in times past:

You can, however, see the marked changes afoot when looking at the mean 500 hpa heights:

The main vortex lobe on our side of the hemisphere has moved to our NE and it's a case of sorting out that residual area over Canada while watching the Azores High weaken and shift further west ready to ridge north toward Greenland.

I imagine that differences in timing between the runs mean that there are enough with the vortex still on its way over to counteract any that have the ridge building by day 10. 

Actually I can check this using the spreads:

Okay, so not a vast spread in that region but with the low heights not that pronounced there on the mean, that still makes the difference between a ridge and a trough. No runs going for a particularly strong ridge at that time though, let alone blocking high over Greenland.

But then, it's only 1st Feb we're looking at here - so it would be a remarkably fast evolution to get us that far that soon!

Time to get some sleep and let the 00z runs come around. How much longer until the first of the epic, overly keen runs that usually appear ahead of a pattern change? 

Almost certain that all of March will be somewhat colder than all of December... Yup December was that extreme. 

This just about sums it up.

.

THE HORROR 1080p - YouTube

No real changes in the reliable frame up to 144.

Haven't checked GFS beyond that range yet but GEM at 192:

It then keeps the same theme out to 240.

At 240:

From a personal POV, this is the best set up. Higher heights over Iberia with a flatter pattern keeps away the mildest of the warm sectors.

The people of Bergen will now be getting their annual flooding issues:

http://www.wetterzentrale.de/pics/MT8_Bergen_ens.png

The higher parts/mountains of Hordaland will easily achieve several hundred cms of snow over the next 10 days if the current output verifies.

Sorry for talking about Norway but I can't think of any positives for much of the UK atm. That said, I do think the Scottish ski slopes will be getting some action too  

Still apt after the 0z...

None of these will be required on this side of the pond.... ...(at least in England, maybe in Norway though...)

Still looking very non descript this morning. Think it's also worth highlighting how the cold block we we were talking about last week is expected to quickly erode and be shunted eastwards. It's not even as though we're on the edge of the cold and a shift rather than a tweak is needed for winter to return to the UK.

Could we be looking at more date records as we go into February?

http://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/gfs/00_231_mslp850.png?cb=207

Holy Bartlett! Would provide useable weather

Indeed. I'm surprised how quickly the TV forecasters (Met?) seem to have discounted the possibility of a return to December's exceptionally mild weather.

I think what they seem to be discounting is the chance of another extended spell of very mild weather, like we saw throughout December. That isn't to say we won't get days as mild as we saw that month again in the near future, but as far as I can tell, they seem to believe that another protracted very mild spell is unlikely.