The lowest 850s on GEM are right at the end of it's range when the Northerly pulls -4s at 850.
That's not 'truly cold' by my reckoning but it's a start I suppose.

The idea that the upper cold to our North is not as cold as normal hasn't been really tested yet due to the lack of a decent Northerly blast. I would like to see one develop to find out what an Arctic blast can do these days.

ECM is certainly chilly for sure and ends on a decent note

Oh God, here we go again. I'm not going to get suckered in again Mr ECM

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY WEDNESDAY JANUARY 21ST 2015.

NEXT UPDATE THURSDAY JANUARY 22ND 2015 08:00

THE CURRENT GENERAL SITUATION A weakening Low pressure area across Southern England will move away South today leaving a weak ridge of High pressure across the UK tomorrow.

MODELS-2 WEEK HEADLINE Changeable with rain at times but some drier spells too. Less cold. Turning more unsettled and colder again later with some snow in places, especially over the North.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows the flow moving North over the UK through the coming days as the trough weakens over Southern Europe. However after some days the flow is predicted to move back to a position South of the British Isles in a week or so.

GFS OPERATIONAL The GFS operational today shows a series of coldfronts crossing East over the UK later in the week and again later in the weekend bringing rain at times in from off the Atlantic in temperatures nearer to average at times but still cold enough for night frosts behind the fronts and wintry showers to the NW. Then later next week all areas become under the influence of cold zonality with plenty of rain and strong winds mixed with spells of wintry showers including the South with temperatures falling back to rather cold levels again.

THE GFS CONTROL  The GFS control run is very similar in the first week with several cold fronts bringing less cold air in from the West with rain at times and bright weather in between when frosts at night could occur. It shows a marked cold snap under a Northerly in 10 days tme with no dount some snow in showery form almost anywhere before the flow is cut off once more with less chilly Westerly winds and rain at times later in the run.

THE GFS CLUSTERS The GFS Clusters today show overwhelming support of 70% or more that in two weeks time the UK will lie under West or NW winds with rain or showers at times with snow at times on higher ground of the North as Low pressure is likely to lie to the North and NE of the UK with High pressure well to the SW.

UKMO UKMO this morning shows milder conditions at the weekend and start to next week as weakening cold fronts cross the Uk from the west with some rain for many followed by brighter conditions. High pressure then ridges strongly towards the UK from the SW with dry and bright if frosty weather possible by night but bright days with sunny spells early next week.

THE FAX CHARTS The Fax Charts show a 'col' area slipping South over the UK tomorrow clearing away todays messy pattern from the decaying disrupting trough. then over the end of the week and weekenda series of fronts bring cloud and rain followed by brighter weather over the weekend before a warm front approaches from the West late in the weekend.

GEM GEM today shows a continuation of a basic NW flow with troughs of Low pressure crossing East and SE across the UK at times bringing less cold air with rain at times followed by clearer, largely dry and bright weather with night frost. Later next week the weather becomes more deeply unsettled and cold again with Low pressure to the East bringing cold North winds and snow in places.

NAVGEM NAVGEM shows a similar evolution taking us up to the point in a weeks time when the westerly flow across the UK at that time becomes more disturbed with more prolonged and heavier spells of rain as pressure falls away with stronger winds as a result.

ECM ECM this morning shows a series of cold fronts crossing steadily East and SE across the UK over the coming week with occasional rain and temperatures generally closer to the seasonal average though not discounting frost at night in clearer interludes and wintry showers across the NW. Later in the run a plunge of cold Low pressure to the NE and East of us sets up a much colder period again with snow or snow showers in many places under a cold North flow to end the run.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart today is much more supportive of the risk of cold NW winds returning by later next week with strong support for Low pressure to be centred over Europe with a cold and strong NW flow over the UK giving rise to wintry showers for many especially in the North.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend today is for the models to be indicating a strong chance that a return to colder weather is in the pipeline in a week or so with the return of some snowfall in places

MY THOUGHTS We are approaching the beginning of a less cold period across the UK as the cold pool of air currently across the UK gets shunted away East over the coming days. In the process there will be some rain bearing fronts pushing through before brighter skies and dry condiftions follow for the weekend. Frost could still occur at night and temperatures don't look like exceeding average levels for late January. It may then become a little milder early next week as some mild air wafts over the UK for a time again accompanied by some rain, especially in the North. All models then indicate thet we look likely to dip into cold zonality again as pressure deepens to the North and spreads down across the UK next week bringing wet and windy weather. Later still there is strong support that Low pressure migrates to scandinavia or Europe in general and with High pressure ridging North somewhat through the Atlantic cold NW or even North winds look very possible with cold air sweeping South to all areas giving rise to sleet and snow showers to all and if pressure stays low enough some longer spells of snow too especially over the North and East. The question then is how long this lasts before the Atlantic wins back ground again. Well of course it is impossible to say at such a range and coldies should be encouraged that the pattern looks like setting itself into a cold scenario again so soon after we lose the current one. As I hinted at yesterday it comes as no surprise to me that charts are showing this evolution and as I have been indicating most of the Winter so far we have to look to the NW or North for our cold this Winter rather than East or NE and I see this changing little in what's left of the season. So all in all after a brief less cold period there again looks something to look forward to as the models firm up how this new pattern develops over the coming days. It is encouraging though to see such cross model support though at this early stage. Let's hope it is maintained.

northerly winds are pants down here.. Crisp sunny days and frosty nights. But seeing it's fast approaching February those sunny days will feel rather pleasant in any shelter from the wind, that's assuming it's a strong northerly wind.

EC began offering potential for a larger-scale veering of flow later (10+D period) in EPS suite of 24hrs ago. Yesterday's 12z, as I mentioned last evening, also offered more veered solutions (including a few going to NE'ly, accompanying trough disruption) with generally more meridional upper pattern. The 00z EPS are trickling-out at the moment, so not yet checked. The broad potential for a switch to colder NW-N-NE outcome, although at present not considered to result in anything too extreme (cold-wise), is something we are watching closely for signs of better continuity in EC and MOGREPS.       

From Mr Fergusson on NW

Offers a bit of hope

Plus

Strong broadscale support for the markedly veered, colder solution in 00z EC DET amongst EPS circa 29-31 Jan (pronounced trough just E of UK), but likely a short-lived phase based on direction of clusters thereafter into early Feb.

Slightly OT I know, but can anyone give an example of the most potent/ widespread northerlies the UK has ever experienced on record?

Not for everywhere..snow lying for a week upto 21cm and  -11c and several ice days..winter to me 

Is that the discussion forum equivalent of waving your wedding tackle inside a lion's mouth?

Maybe June 1975.. snow as far south as London. 

Okay so not perticually cold, but .for the time of year it was. It brought first summer snowfall for Southern England since at least 1888. 

Interesting model runs this morning. To my mind it doesn't look like staying milder for terribly long if the runs verify as shown.

Good post Squish and surprised to see some sort of semblance of agreement at 240hrs between so many models, some sort of Northerly influence seems quite plausible. As you say, however, if this does come to fruition it will probably be a watered down version..........but you never know!

Here we go again... 

The strat. vortex is displaced right over to Siberia in the near future, with some warming going on over Canada and Greenland, and this brings the potential for an at least temporary disintegration of low heights to our NW, with the focus of low heights trying to get to Siberia.

A complication arises in the form of blocking trying to establish over the high Arctic which may serve to disrupt the westerly flow and send those low heights plummeting into Europe.

Both ECM and GFS went with this on their 00z op runs, but while ECM does amplify the Atlantic flow and allow the Arctic High to establish strongly (a very promising day 10 chart), GFS kept the jet stronger and didn't allow either of those things to happen.

So once again, some real potential showing up starting in just over a week's time, but what lies on-route is some fairly benign weather with a mix of milder interludes, spells of rain, and some chilly conditions - most so over the next few days with some hard frosts on the cards.

Finally, though I may sound like a stuck record, there remains a lot of uncertainty over possible MJO influence starting some 10 days from now. Same as in early January, GEFS are showing a strong event but ECMF is not interested. Will GEFS land much closer to the mark again this time around? We can only wait and see. The possible impact of a new strong event ranges from a deep mid-Atlantic trough to very strong high latitude blocking, depending on where the tropical activity takes place... so no clear signals at this stage.

That's the kind of strat chart I like to see, rather than warming over Siberia pushing the vortex into Canada. I'm starting to see the potential for some deeper cold as we end January and go into February. If it can coincide with my week off work from Feb 2 then that would be ideal 

Having said that the 06Z GFS op doesn't look too inspiring.

Just for Frustration:

Marcus?> - Your inbox is full.

A bit of a rain sandwich for me there. Not to disheartened I'm sure it will chop and change a few times over the next couple of weeks.

More support for the Euro trough and a strong PM flow this morn. The ECM op looks an extreme example of what could happen. The Azores high continues to be strong and looks to ridge into the mid-Atlantic. If we want anything more than cool/cold zonality and topplers we of course want the darn thing to be nuked up to Greenland but can't see much sign of that.

Could be some interesting weather anyway with gales, rain, blustery thundery showers, sleet/snow mainly to the N and high ground. Possible northerly blast giving something further south if we can get some big amplification looks lower probability at the moment. Vortex still looks strong around Baffin.

ECM ens anomalies day 9

NAEFS shows a similar anomaly pattern but flatter than ECM

What I meant is that there is a way that we can import air directly from the arctic directly which hasn't really happened so far this winter. So no real cold at 240hr on the GEM but perhaps subsequently assuming this comes off.