some great posts this evening and some cracking output on the models. more red herrings ahead ?  ive learnt not to take these charts to seriously, at this range,  

Check out the difference in the western North Atlantic - GFS/GFSP's positively tilted trough (left) against ECM's negatively tilted trough (right).

The latter allows heights to remain on the higher side across Greenland which helps to send the jet diving south sooner, keeping the Atlantic high further west rather than allowing it to slide east before declining south as the GFSP 12z run goes on to show.

It's a good sign that the GFS/GFSP versions reload the mid-Atlantic ridge not too long after, but it's a delay that I'd be happier without if I'm honest, though I'm fully aware that the slowest possible route to a cold setup is nearly always what we end up taking.

In theory, with the background drivers finally pointing towards amplification rather than a flatter pattern, ECM's true forecasting might should start to come through a bit more, with it's far better record handling sliding lows in such situations potentially coming in very handy... though even it is struggling with how exactly the western North Atlantic trough behaves in the 8-10 day range. The SE motion for the 10th day is consistent though, as it has been for the most part on the GFSP runs, though the recent tendency to slide it more to our east rather than right down over the UK is a departure from previous days.

I actually think GEM is also in with a shout at the moment, as it gets where it does largely as a result of being a bit less progressive upstream, which is not an unreasonable suggestion when there is a net trend across the models to weaken the jet.

Having said that, it does tend to get a bit carried away with the amplification, so the day 8-10 output is probably rather optimistic.

Now for the usual MJO update:

The bias corrected GEFS continue to show it reaching phase 7 highly amplified before decaying there. A good way to leave a phase 7 influence as the dominant MJO forcing on the pattern.

ECMF have increased the amplitude at which the MJO arrives at phase 7, now sufficient to start expecting some influence on the pattern i.e. a build of high latitude blocking. It decays more slowly than shown before so again, a phase 7 is now the favoured influence, allowing for a lag in response time and impacts could start to be seen about two weeks from now.

UKME still has a faster decay than only just makes phase 7 before becoming too weak to have much influence. The adjusted version is a bit slower but the overall progression is faster than GEFS and ECMF even at a few day range so seems less then trustworthy, though it could be that the plot has a longer time interval between points.

Overall, GEFS and ECMF seem to be very slowly coming together, which just happens to mean they're closing in on the best-case scenario of a decline in phase 7.

It remains to be seen just how strong the MJO is on entering phase 7, and then how much influence it has when compared with anything from the stratosphere or other drivers (SSTs for example), but I do find the recent MJO trend very encouraging.

The EC-32 run didn't make it to phase 7 before decay, which goes at least some way to explaining what was a generally zonal outlook for the third week in particular. Hopefully just a bit behind on the trend - fingers crossed!

I think the 12Z and the 18Z suite is following my earlier assessment rather well. One interesting thing is we seem to get into a situation where stuff from the NW increasingly improves the overall pattern, so that eventually we could well end up with a greenland high. There is really a lot of optimism in the output for cold weather fans, though patience is not optional! Very pleased with all of the models, and ofc the GEM is still an easterly sympathiser, I think its an unlikely course of events but we'll see how this pans out by tomorrow. 

Very pleased about how things are shaping up! 

Hi Carla,

You can select the 'GEFS' panel in the TWO chart viewer here: http://www.theweatheroutlook.com/twodata/datmdlout.aspx

Then choose a location under 'line graphs'. Perhaps you could take two in your case - Norwich and Sheffield - and consider something halfway between the two as an estimate?

Hope that helps 

- - - - -

Back to the model output, and the GFSP 18z has shifted closer to ECM/GEM in terms of the angle of the trough days 8-10, though it's still not quite enough to maintain the higher heights over Greenland. Instead something close to GEM to evolves with a strong ridge toppling onto a broad NW Europe trough, cold for a good number of days with some snow chances across the south in particular.

The jet remains a lot more vigorous though - so much so that the trough pushes all the way to Svalbard before coming to a halt! Sounds a bit rubbish, but with the cold continental air mass in place over the UK as this happens, we see the sort of slow, stuttering breakdown than can have snowy results. The outcome is quite mixed on this particular run.

We also see the notion of high latitude blocking in the vicinity of Greenland days 15-16, consistent with the 12z. A good reflection of the longer-term potential as it currently stands.

Meanwhile, GFS has showed no real trend at all on it's 18z op, but it's consistency with the previous op run works against it here, as the American's main forecasting centre (NOAA) totally rejected the 12z op run beyond +150 hours in their discussions (or so I have been informed).

Just seen Q's post, looks like we're signing from similar hymn sheets 

We are seeing a strong signal for each new bite of the apple to bear more (cold and wintry...) fruit than the last. Not only that but the first bite is looking about as effective tonight as it has done at any time this past week or so 

Now to spend the night dreaming about what a wintry apple might look like 

Hope that dream is  a  W...Hite one...

Clever dodging of the wrath of jinx there 

Looking at the Wetterzentrale as I have some free time I saw -10C uppers almost made it to Ireland and if the exact position of the isobars without altering it which brought a milder sector in it before the next cold -5C uppers arrive covering the whole UK again.

If this isobars does not alter I am sure the -10C uppers would had landed here from the west with copious amount of snowfalls generated from the warmer ocean.  Surely it would happen one day.

Ens mean suggests strong support for at least a brief northerly blast

http://modeles.meteociel.fr/modeles/gens/runs/2015010918/gens-21-1-192.png

You can get GFS ensembles for wherever you are by clicking on the map here:

http://www.meteociel.fr/modeles/gefs.php?carte=1

The Chinese and the Canadians would have HLB in place over the Faroes by day 10.  I believe their weaker modelling can get things woefully wrong as we saw around Christmas time.  Therefore I will post a GFS chart as they lead the way then: A very different outcome

Not much difference between GFS and ECM this morning.

ECM at day 10:-

Good agreement all round.

The copy and paste weather forecasts and the rinse and repeat charts forming a good bond

0z ECM ensembles (click to enlarge) - looks ilke the control run went off on one today! It shows either very cold rain or a dumping of snow... I'll be able to find out later when the full charts are issued.

Fun control runs aside, there remains a decent chance of colder-than-average conditions mid-term.

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY SATURDAY JANUARY 10TH 2015.

NEXT UPDATE SUNDAY JANUARY 11TH 2015 08:00

THE CURRENT GENERAL SITUATION A strong Westerly flow will extend to all areas today lasting through tonight before a warm front approaches NW Britain tomorrow.

MODELS-2 WEEK HEADLINE Continuing mostly unsettled with rain or showers at times. Near average temperatures will fall rather cold at times with some snowfall at times on all higher ground.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows a very strong Jet Stream being maintained across the UK in the short term. It weakens steadily with time but remains sufficiently dominant to control the weather in what will appear to be a cold zonality spell of weather in a WNW to ESE moving flow close to SW England later.

GFS OPERATIONAL The GFS operational shows a very disturbed week to come with a very strong Westerly airflow blowing across the UK with fronts rushing East in the flow bringing spells of cold and showery weather with snow on hills. A deep Low close to midweek brings a brief spell of less chilly and wet weatehr and severe gales before a general cold and showery pattern develops late this week and next weekend as winds veer slowly North. Then the latter stages of the run are dominated by a pattern reset as the cold ridge collapses and Westerly winds with rain and wintry showers return.

THE GFS PARALLEL RUN The Parallel run is broadly similar in the sequence of events throughout the period with cold zonality the order of the day through the second week as further weaker depressions than of late maintain an Atlantic driven package of weather with the bias towards colder and showery conditions  overriding the short milder interludes with rain.

THE GFS CONTROL The GFS control run too shows the powerful storm in the middle of next week with it's attendant very wet and windy weather. The sequence thereafter remains Atlantic driven with plenty more Low pressure shown crossing East over or to the North of the UK with spells of cold and showery weather with short milder interludes when rain and gales are possible.

THE GFS CLUSTERS The GFS Clusters show a mixed viewpoint this morning with 35% split each between a brief Northerly followed by a toppling ridge or milder Westerly winds returning over the UK with rain at times. There is a 10% cluster which show a direct Northerly while the other 20% show a cold zonality pattern in mostly NW winds.

UKMO UKMO continues to project a very unstable and cold Westerly flow across the UK next week. This type of pattern will deliver cold conditions at the surface with strong Westerly winds and spells of wintry showers for all Northern and Western areas in particular. A new depression midweek would bring a short mild and particularly wet and windy spell before the cold and showery westerly winds sweep back over all areas later.

THE FAX CHARTS The Fax Charts shows a continuing changeable theme surrounding two types of weather. One being mild, windy and occasionally wet weather and the other cold, windy and showery weather with some snow on hills across the North, the latter more likely later next week.

GEM GEM today shows very disturbed weather across the UK through the next 10 days culminating in a pattern change by the end of the run. Through Week 1 as is documented by other models Atlantic Low pressure areas crossing East over or near the UK bring spells of rain, strong winds and variable temperatures, sufficiently cold for snow at times over many hills especially later in the week. Then as we move through next weekend and the start of the second week rising pressure over the Atlantic and then to the North of the UK tilt winds first Northerly and then Easterly and with Low pressure caught up in this colder air some sleet or snow is expected at times across England and Wales in particular..

NAVGEM NAVGEM reflects no end to the Westerly flow with sometimes mild, wet and very windy conditions over the UK mixed with colder periods with showers in between with little change in overall synoptics shown one week from now. It too shows another powerful storm system across the UK midweek exacerbating the unsettled and stormy theme.

ECM ECM this morning also shows a lot of strong Westerly winds with spells of rain and wintry showers to come for all especially across the North. As with all other models it too shows a major storm system midweek with very wet and windy weather for all for a time. Then cold and showery weather returns before a brief cold ridge crosses East next weekend ahead of more Atlantic domination returns from Low pressure North of the UK with rain or wintry showers at times.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart shows a rather chilly prospect under cold zonality this morning with a WNW flow the most likely option with Low pressure to the North and a trough over Europe driving spells of rain followed by colder conditions with wintry showers at times in from the West and NW..

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend this morning remains quite Atlantic driven overall with a brief drier interlude next weekend ahead of returning Atlantic Westerlies soon afterwards.

MY THOUGHTS The strong Jet Stream remains totally in control of the weather across the UK for another week at least. Further marked storm systems, especially the one midweek look like delivering some nasty weather with some disruption from high winds, heavy rainfall and maybe snow too later as it exits away NE by the end of the week. The cold zonal spells which will dominate other times will in themselves bring some snowfall to quite modest levels at times and it will often be quite wintry in the NW. Then once we leave this week and move into next weekend there is some support for the Jet flow to be disrupted as a ridge of High pressure edges into the UK from the West, damping down the wintry showers and allowing a period of drier and frostier type weather. However, almost without exception this looks unlikely to last as the Atlantic bandwagon regroups to the North and NW of the UK with further rain and strong winds alternating with colder showery spells look the most likely option to develop again through the second week. The GEM operaional does fly the flag for the cold fraternity this morning rising pressure sufficiently to create a High pressure cell North of the UK with a cut off cold Low over the UK bringing the risk of snow and cold conditions but this scenario does look rather isolated in an otherwise Atlantic dominated pattern. We are now at the point where the Northern hemisphere has reached it's coldest point and even Westerly winds over the UK can deliver snowfall in places and I wouldn't be surprised if some places even in the South don't at least see something of snowfall over the next week or so, mostly in the form of wintry showers but full of interest nonetheless. However, if it's something rather longer lasting cold rather than fleeting your after then there still seems little overall signs that anything from an European direction is likely antyime soon with as of the rest of the Winter so far North being our best direction to obtain fleeting glimpses of Winter in a mostly NW flow as that old friend the Azores High while being less influential over the upcoming period remains a thorn in the side for anything noteworthy to develop and sustain.