Just skimmed the 12z GEFS into FI.

I see signs of a chilly, messy picture, possibly something similar to December 2017.

Frosts where skies clear, plenty of snow for the hills and at times at lower levels. 

I’m not convinced of a significant, severe cold spell, but not much mild weather is on offer either. 

Take P10 as an example http://www.wetterzentrale.de/maps/GFSP10EU12_324_1.png

Transitory ridges to our north with plenty of chilly air on offer, lows being forced to run further south likely to cause a few surprises too. 

What will the Euros bring?

Yes I think that is a fair summary. The trend is clear for chilly conditions midmonth, the details are not.

While the pattern is clear it is also interesting to see (here at least) that the divergence including options o a much colder scenario appears from around the 12th on ththe latest ensemble set. http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&lat=57.2&lon=-2.3 

Not without interest and given the oroj cited unsettled nature of the output it will be a good deal different to current and recent conditions for many people.

Or did it? 

Lots of forecast I read (including the Met Office contingency) seemed to suggest a back loaded winter with the second half being colder than average and the first half milder. I didn’t read any tabloid ones for obvious reasons. On the 5th of January with the output the way it is I see little reason to think they may be wrong. 

I totally agree , I said a few weeks back when HP was looking dominant over us ……." Is this the blocking we were waiting for , but in the wrong location " The LRF's are looking like they were wide of the mark …………...at the moment , maybe just maybe the HLB will show its hand in Feb and March rather than Jan and Feb?

Indeed. It's almost as though the computers have been saying one thing and the real world the opposite. I can remember Paul Bartlett saying he looked for cold and cyclonic Novembers as a cold winter indicator. I suspect it's quite possible he would have gone against the grain and called a milder than average one this time. 

Are you forecasting a milder than average February and March and which forecasts are you referring to as I’d like Tom go back read what they were predicting? 

If people had forecast a cold December that was obviously wrong but January and February are very much yet to be determined. After a cold start and a cool down from midmonth it would be a brave person to call the rest of the winter. It could well end up a little be.ow average. (or well below or well above). 

On the topic of actual model output the ECM 12z continues the theme the GFS/P have established over the past week. 

What is pretty clear from the model output we have at the moment is that, contrary to what one or two members were predicting around Christmas, there is little or no indication of the HP currently controlling our weather slipping SE into the continent. If anything, it is being shown to gradually retreat into the atlantic allowing a NW airstream in across the UK.

If anything, the output we have seen since last weekend has increased my interest in our prospects for later in January and as we go towards February. As I said above, the prediction from a week or so ago of the high moving SE into the continent doesn't look like coming off, at least for now.

Yes, I think the High is unlikely to slip SE giving us SWly winds and what is more likely based on the output is for higher pressure at northermost latitudes basically displacing everything southwards leading to a colder and rather mobile picture at times.

How far south and how cold is a different matter (therefore some further south are wondering what the fuss is because it’s not a raging easterly ) 

Another question is will the more merodional pattern allow high pressure to develop in a manner suggested by one or two of the recent models such as the current 12z GFS op run? It’s possible but to early to tell IMO.

The NAD (North Atlantic Drift) is an ocean current, the extension of the Gulf Stream out across the Atlantic. Not something that ICON or GFS show, to the best of my knowledge. If it ever should shut down, the effect on the climate of western Europe would be huge.

won't disagree you are seeing something I am not !!

Still fun watching with every run at the moment however

http://old.wetterzentrale.de/pics/MT8_London_ens.png 

Really? The mild December seems pretty much as expected, maybe the cold will arrive a week or two later than some were hoping but weren't most long-range forecasts going for a "back-loaded" winter this time round? Of course it might not arrive yet but it seems a bit premature to pass judgement yet!

As long as that mean stays below average from mid-month I see no reason to be too despondent yet. Still ten days to the 15th after all - much to be clarified! 

if that shuts down everyone will be looking for the 4 months we have thawed out and storing food in the permafrost!!

Changes definetely afoot as we pass middle of month and head towards last third. Timing of this to coincide with down welling of strat forcing although with several false dawns  and time range scepticism is understandable. 

We should start to see some inter-run consistency going forward now with much stronger northern amplification showing up in the coming days.

My punt would be for Atlantic ridge linking with Arctic and Russian high with lobe of vortex cut off over central/northern Europe feeding bitterly cold east/north easterly aiflrflow over UK by 25th.

Not asking much surely. 

I seek cold and I am not disappointed by those. Plenty of cold runs on offer from mid month, and we know not to expect anything before that.

So, given that winter stretched into March last year, it is arguable that we're barely a third of the way through 'winter'.  We have a SSW and an associated split polar vortex.

We have great uncertainty in the charts and a good number of ensemble variants serving up cold weather.

To be honest I don't see any reason for some of the downbeat assessments.

You should also mention the PFJ and the STJ of the Jetstream flow, as when the STJ aka Gulfstream goes over the North Atlantic we sometimes get the Canadian High pushing into the NW Atlantic, blocking the Subtropical energy Jet of the Gulf Stream.

As High Pressure allows as per ECMWF on Saturday the 12th, we see our Bartlett High be pushed away to Mid North Atlantic area, and cold Canadian air does indeed dive SE from Iceland, and on the GFS, we see NW Atlantic see Newfoundland Low get cut off, aka the diversion of the Gulf Stream to NE USA side with WAA to Newfoundland Nova Scotia etc.  High Pressure moves SW from NW Atlantic before this happens as the Greenland High builds and that Low over NF spins around there heading to SW Greenland shortly after (in 10-11 days from today).

The Cold SE Canada Labrador Current is pushed to North Atlantic as a Low gets cut off Over Iceland on January the 12th, as per ECMWF show on 12z run, and then we see more disruption to the STJ by Tuesday and Wednesday the 15th and 16th, allowing that cold air from Iceland and Canada and the Arctic to our North a way in to give us some much needed cold frosty weather with snow showers in North and NE as well and N. England on offer.

And to see the Greenland High affect the North Atlantic is good as well, and so would be getting Norway High shortly after 15th, allowing cold NE flow over the UK, or maybe cold arctic Northerlies, that would be some NAD shutdown hey.

GFS, is having egg on it's face today, as 12z ECMWF for 12th and 13th January is another good puzzle to laugh at... NW flow, Saturday 12th, cold arctic Northerly flow on 13th.  And what with the GFS and ECMWF and ICON getting the Eastern UK in for some cold northerly flow this Tuesday night and Wednesday 8th and 9th, with cold frosty night and first half of day Thursday in the SE of England, that is at least -5 at T850hPa.

But downgrades to Arctic Northerlies do happen often, so the NAD Shutdown joke melts as air from the SW and the Bartlett High get more chance to affect us, as we have had in last 2 weeks experienced!.

Yeah I mean also that it could be less cold on Monday the 14th and the Jan. 15th, as the cold NW flow is approaching from our West NW off the Cold North Atlantic waters hmm.

.

Plenty of pizza being served up around mid month on the 18z 

Yes, a view i fully support at this point. It is one thing saying the models don't show much promise for severe cold at the moment but another to say the end of January can be written off on the 5th. Have a look at the charts for the first week of February last year and see if they predicted recorded breaking low temperatures at the start of March.