Computer models have backed away from a cold easterly next week and now show a more mixed outlook. Nonetheless there is a good chance of further cold incursions as we head towards the end of January and into February.

7 day average unchanged from the 06z

Milder air spreading a bit further south on the 12z at D7

Is there a chance of a complete flip back to the easterly or is the writing on the wall?

Nightmare forecasters and frustrating for cold and snowy weather enthusiasts! 

I have posted this again on here as the last thread was locked 10 seconds after I posted this...

SO....Looking at the more reliable time frame in less than 3 days time:

Many of us will either wake up to a covering of snow or see snow falling on Tuesday so even if this blocking doesn't properly come about, then at least we would all have seen some snow by the middle of next week on the plus side? - albeit wet and sleety and if precipitation is heavy enough there could well be convective cooling and quite a lot of accumulations of snow - very sticky and wet snow though!?

TEMPS MID afternoon barely above freezing!? - So an upgrade in the short term GFS Op run?

The track of that very cold air coming out from Canada is too clean looking on the models. I reckon cold air exits as forecast that there will be a greater 'reaction', so to speak, with the warmer than normal Atlantic. This could enhance the development of a bomb low/lows, but at the cost of warming the air mass significantly before it reaches this side of the pond. 

It seems less likely with each successive run that shows more energy in the northern arm of the jet.  That has always flattened the pattern and squeezed any Scandi high away east or south.

Watch for the necessary building blocks that are required around mid-week; if they're not there then the easterly is off the table this time.

PARA keep things cold midday on Tuesday too with sleet/snow showers:

Looks to me like about 8 or so members still setup an Easterly on the GEFS. I wouldn't be nailing the coffin just yet.

EDIT - call that 6! Being optimistic there.

The general theme in the longer range remains largely unchanged:

http://www.wetterzentrale.de/maps/GFSOPEU12_384_7.png

Quite incredible that there seems to be more certainty about the longer range output (relative to the time frame of the operationals) than the mid. 

Indeed and quite surprised they’re still there in numbers. I wonder if the starting tweaks include slight adjustments to the US storm with consequences down the line.

As unlikely as it is, the EC is in prime position to pull another swing back to the Easterly to prolong the pantomime.

No doubt the ECM will bring it back just to annoy/confuse everybody. 

On the subject of the GFS ensembles, for what ts worth in the short to medium term they seem a little colder than the previous set. (The longer range is not available yet at time of writing).

Edit: Beat me to it Neil!

Always a good chance... plenty of time too.

Lets not forget how to the cold behaves on tuesday might also have an inpact. So much weather to get thru before the easterly was due to hit... so plenty more rolls of the dice.

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The ICON has further Low Pressure tracking across the UK, by Thursday night Friday and Saturday- and looking at further Low Pressure linking to that one in the NW Atlantic ready to track in behind it maybe to the UK from Northwest N. Atlantic Sea.

GFS FI, T180, UK sees heavy rain and Deep Low Pressure tracking across from the North Atlantic Sea, Monday and Tuesday Cyclonic West NW winds and very cold T850's, rain sleet and snow showers expected if that happened, Jan. 28th and 29th January, another Short wave Deep Low join this parent Low, tracking across the UK on January the 30th et all, and lasting to Thursday 31st, with further cold plunge with rain to snow possible.

Further down, cold with widespread night frosts and Southerly tracking LP's from West to East across the South of North Atlantic moving west to east with High Pressure in Northwest N. Europe and North Atlantic Sea as well come early February- 12z GFS is showing it.

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Pantomine is a pretty apt word to describe the current model schenanigans, IMO.

Seen it all before though at this time of year on many occasions, last February being the most recent instance of mass model uncertainty in the semi-reliable timeframe.

Some encouraging signs of cold trying to hang on (from an easterly direction) in the GEFS short ensembles.

Why would anybody need to look at the models when you get excellent analysis like this? Can just picture the charts as they are explained here. 

Yes a few easterly runs in there but the majority going zonal with double figure temps.

Quite so.

The Laiq effect.

Positive at all times.

GEFS 12z 6 7 8 9 10

16 17 18 19 20

So T+144 increases since the 6z the number of Ps showing a NEly outcome.

Not implying anything- just giving a stat.

I certainly don't see the majority in double temps, the LP's are sinking so far South 

Here you go Marcus, the t2m ensemble data for London on the 12z set.

Generally the 12z suite is better than the previous one in terms of cold. This is the t850hPa set for my location. http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&lat=57.2&lon=-2.3 

Martin

Could have been a lot worse.  Yes, the 12z GEFS favours Atlantic based cold as opposed to a very cold easterly incursion but the split is clear to see and there might be life in the old dog yet!  Let's see what the ECM brings!!