Model Output Discussion 4th Dec.2013-12z onwards.

[IDO]

Yes Frosty, potential in the GFS Op. However it has little support from its members currently. The pressure chart for the ens:

 

 

That is outlier territory. Though interestingly the control also suggests a very unsettled potential: 

 

The GEFS mean at T384:   ...little change.

 

GEM at T240:   ECM at T240: 

 

No real change within the ten day period. HP to the UK's south with varying degrees of zonality the further north you are. FI on GFS ensemble wise still along these lines but like last night's ECM ens both offering a more unsettled profile run to run in fantasy land:

 

 

 

 

[Gibby]

Good morning everyone. Here is my interpretation of the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Sunday December 8th 2013.

 

The General Situation. All models show a pattern of High pressure over France with a Westerly flow of winds across the UK, strongest in the North. Through the coming week the trend will be for winds to back more towards the SW and then South with even milder air affecting the North and West in particular through the coming week with some further rain at times towards the NW as Atlantic fronts brush by. In the SE there are still some signs that it may be a little less mild than elsewhere with a drift off the Continent for a time midweek and mist and fog could be present on some nights between now and Thursday. Towards the end of the week though High pressure remains stubbornly to the SE and mild SW winds will affect all areas with further rain in the NW which may extend further SE next weekend in what could become very windy weather in the NW.

 

GFS then shows next weekend as windy and mild with rain at times. This extends into week 2 with the trend for winds to veer more towards the West and later NW drawing colder air South and East across the UK behind successive depressions and cold fronts with temperatures returning to normal and a little below in the North. With rain at times likely for all by then some of this will fall as snow over Northern hills before the end of the run.

 

UKMO for next Saturday maintains High pressure down over SE Europe with a broad and mild SW flow over Britain with troughs out to the West delivering some rain to the North and West of the UK while the South and East remain largely dry but cloudy.

 

GEM today keeps High pressure over Germany next weekend very much in control with just local variations on temperatures and cloud cover the only likely items of interest in an otherwise benign pattern. The High does show signs of weakening for a day or so before intensifying again near SE Britain at the end of the run with a renewed period of fine weather but maybe a little colder with mist and fog possible in light winds.

 

NAVGEM is resilient to showing any major changes either as it ends it's run with mild SW winds bathing the UK in dry and rather cloudy weather though a rogue weak trough could deliver a little rain for a time next weekend and rather more frequently over the NW.

 

ECM does also show a rather windier spell for all next weekend but still potentially very mild in a strong SW breeze. Occasional rain could occur almost aywhere as weak troughs pass NE but this becomes restricted to NW Britain later as High pressure remains in total control stretching in a belt from the Azores to Southern Europe by early next week and lockning the UK in a mild SW flow for some considerable time to follow Day 10 if verified as shown.

 

The GFS Ensembles this morning show little change to that being shown in previous runs. There seems little support to exit the UK out of this locked pattern of mild SW winds which only slowly lose their very mild uppers status late in the run. However, a drift to average upper levels is unlikely to make much difference down at the surface as SW winds just become more unstable with rain at times for all likely later with winds still blowing for the most part over the UK from a mild Atlantic point.

 

The Jet Stream this morning remains at odds with delivering cold weather with the flow running NE strongly between Scotland and Iceland. Over the coming week this flow moves even further North for a time before the continuing trend to slip it back further SE to be crossing NE over the UK in Week 2. It's orientation does change slightly late in the run to a more direct East flow over Britain as High pressure collapses over Europe and relocates near the Azores, Southern France and Spain.

 

In Summary this morning there remains little sign of change in conditions over the UK for the next few weeks. In such conditions it is unlikely that anywhere above mountain top location will see a white Christmas this year if this morning's charts verify. The UK seems locked in a South or SW flow with High pressure persistent over SE Europe bathing the UK in potentially very mild and cloudy air. Some local low level cold inversions may affect the South briefly midweek but other than that cold remains on hold for now. Rainfall amounts will be small in the South though the NW could see quite a bit of rain at times as troughs brush past in a strengthening SW flow here later in the week. There are then small signs of this sinking SE to affect many areas through Week 2 with rain at times for all should it occur but it looks unlikely that such a change would result in anything very wintry soon afterwards as High pressure is shown remaining locked strongly over Southern Europe and the Azores.

[bluearmy]

looking through the gefs, there really is no decent guidance. all routes remain ope. the long shote are clearly those that deliver deep cold to our shores but the fact that some members manage it means it isnt out of the question. there seem to be three broad routes through week 2

 

A) standard bartlett sw/ne zonal flow (apart from a few days as the pattern changes, is this likely? how long is it since we saw a sustained period of bartlett?)

 

B the jet slowly aligns nw/se as a trough digs into eastern europe and our block retrogresses into the atlantic. not displaced as far n as we saw a few weeks ago as the vortex just n of greenland wont allow.

 

C) we continue with our mlb and the scandi ridge (sceuro block) to our east waxes and wanes (n/s) as deep depressions run over the top, mainly n of scandi.

 

with blended solutions also possible, you can see that forecasting the run up to the xmas period is not something that can be undertaken with any confidence whatsoever.

Edited December 8, 2013 by bluearmy

[shedhead]

Fair enough Shed... As an aside, the met office app suggests that the temps for the next 5 days are:Reigate: 10, 9, 8, 7, 7Thetford: 9, 9, 8, 7, 7Christchurch: 11, 10, 10, 9, 10Buxton: 8, 8, 7, 7, 6

Hardly a big freeze GP...what do they suggest for Glasgow, Manchester, Cardiff and Plymouth btw?

[Great Plum]

Hardly a big freeze GP...what do they suggest for Glasgow, Manchester, Cardiff and Plymouth btw?

Hardly overly mild either...Plymouth: 11, 10, 11, 10, 12Manchester: 10, 10, 10, 7, 8Cardiff: 11, 9, 11, 9, 10Glasgow: 11.10, 11, 12, 9Proving that the further west you are, the milder it will be... 1 or 2 degrees over the average to the south west? Scotland does look mild though (lowland)

[phil nw.]

Unfortunately with this pattern there's no quick route to cold.

The core of the vortex is in the worst possible area for getting anything decent being stuck over Greenland with corresponding Euro heights.

This pattern tends to change only slowly-here on the T240hrs means it shows into week 2.

http://www.meteociel.fr/modeles/ecmwf/runs/2013120800/EDH1-240.GIF?08-12

http://modeles.meteociel.fr/modeles/gens/run/gensnh-21-1-240.png?0

the only chink of light is the faint hint that the jet may turn more west or north of west further on as the high eases back into the Atlantic somewhat allowing a trough to dig into Scandinavia.This would at least return things to nearer normal with a chance of some colder air into the north.

 

The latest ens graph for Warks.

http://cdn.nwstatic.co.uk/ensimages/ens.20131208/00/t2mWarwickshire.png

 

does show a cooler trend later.

Edited December 8, 2013 by phil nw.

[East_England_Stormchaser91]

GFS is better this morning maybe widespread snow by the 20th, even for the South ? Look N/ N/W..

 

Liking it for snow, one thing that concerns me about this chart is the potential for another storm surge would you believe it. I'm sure it will be spring tides around then too. Goodness me.

[Summer Sun]

It didn't take ECM long to drop the deep low over Scotland on yesterdays 12z run

 

 

A quick look at ECM's ensemble shows only Scotland and Ireland look prone to any rain over the next 9 days or so

 

Edited December 8, 2013 by Summer Sun

[Purga]

Straw clutching in here this morning. The mild signal just gets stronger every day so let's just accept it, it's only the weather and the UK is the mildest place in the world for it's latitude due to many, many factors.

ENS scream mild

 

ECM mean right up to 240hrs

 

GFS / ECM mean anomaly charts = mild

 

 

CPC mean anomaly charts = mild

 

 

All indicators are solidly mild for the foreseeable and with the backing of the natural December type forcings it pretty much a done deal for the next 10-14 days.

 

Of course the detail will vary which is what day to day forecasting is about and remains difficult to pin down to individual locations but the broad picture is pretty much nailed on and significant cold for the bulk of the UK has virtually zero chance of happening.

The odd bit of wintryness in the Scottish Highlands maybe but where 99% of most people live its mild all the way with little rain in the SE and more chance to the NW.

Smell the coffee and enjoy the mild, if you want cold - hop on a plane and go somewhere that has a decent winter for a week or two it's much less stressful than searching for a one in ten thousand chance that we may get the odd ground frost here in the next fortnight.

[Frosty.]

Some more good signs for coldies this morning, not just from the Gfs 00z op run but also from the GEFS 00z control run and several 0z perturbations, there could be a wintry spell with snow and widespread frosts in the days before christmas and potential for further wintry weather during the festive period, the outlook is very uncertain but we at least have a chance of something white.

[pip22]

 

 

 

 

 Oh dear. Looks to me another storm may be brewing in the Atlantic. 150 hrs out. Maybe we need a storm to bring cold weather.

 

 

 

 

North-Westerlies closing by....

Edited December 8, 2013 by pip22

[Frosty.]

The latest Ecm 00z ens mean & GEFS 00z mean are showing a northwest / southeast split for most of the next 10 days + with high pressure maintaining generally settled continental type weather for the southeastern half of the uk with slight frosts and fog but sunny spells at times and lighter winds than recently. The further north and west, especially the northwestern corner of the BI looks milder with stronger sw'ly winds and outbreaks of rain with low pressure domination but with a window of fine weather for a time during the second half of the week ahead. Although the models appear to be fueling up the atlantic low pressure systems, the anticyclonic block across mainland europe seems reluctant to give any ground, until heights lower to the southeast it looks like it could just be the north and west of the uk which has mostly unsettled atlantic type weather.

[pip22]

Unfortunately according to this run it is going to be far from very cold with no cold winds on Christmas Eve. 

 

 

 

It will probably be a frosty one though with at freezing uppers with HP building over us. I'm guessing by Christmas day it will be a frosty/grey (foggy) Xmas.

Edited December 8, 2013 by pip22

[cooling climate]

ECM stratosphere forcasts do not paint a very pretty picture this

morning for those wanting cold. Temps are forcast to drop and zonal

winds forcast to increase as seen below.

[The PIT]

Euro high as we know from the past seems to be stuck down with super glue and can last for weeks. Doesn't look like it will be going anywhere soon either. The five day forecast here from the gfs shows a couple of surprising chilly days which looking at the uppers doesn't quite add up. So I thought about inversion setting in but there's too much wind so I suspect the actual days will be milder than shown. The days in question are Tuesday and Wednesday. The Met have it much milder. 

[Newberryone]

The latest Ecm 00z ens mean & GEFS 00z mean are showing a northwest / southeast split for most of the next 10 days + with high pressure maintaining generally settled continental type weather for the southeastern half of the uk with slight frosts and fog but sunny spells at times and lighter winds than recently. The further north and west, especially the northwestern corner of the BI looks milder with stronger sw'ly winds and outbreaks of rain with low pressure domination but with a window of fine weather for a time during the second half of the week ahead. Although the models appear to be fueling up the atlantic low pressure systems, the anticyclonic block across mainland europe seems reluctant to give any ground, until heights lower to the southeast it looks like it could just be the north and west of the uk which has mostly unsettled atlantic type weather.

Well at least perhaps that's one advantage we have here in Ireland being on the Atlantic's doorstep. Although the latest ecm op run doesn't seem to hold the same strong gale to storm force potential that it had yesterday.  Systems being deflected far more northwest..unfortunately!  

 

Yesterday                                        Today

No doubt the Euro block will lead to further downgrades in Fi

[Frosty.]

No matter how solid the euro block looks, it will eventually be demolished, nothing lasts. I liked how the Gfs 00z bulldozed the atlantic through next weekend onwards, more of that please.

[Ian Brown]

ECM stratosphere forcasts do not paint a very pretty picture this

morning for those wanting cold. Temps are forcast to drop and zonal

winds forcast to increase as seen below.

temps 13.gifflux dec 13.gif

 

Yes this is line with the US forecasts of a very +ve AO for January, and obviously +ve NAO goes hand to hand with this, with an intense PV and the downstream Euro High.

[IDO]

As many members are saying, this setup looks like its set for sometime. Until we get some good strat news I think we will have to prepare for HP close to the south, possibly sinking into Jan setting up a zonal flow. The CFS has been consistent with this signal for the last week or so:

 

JAN:   FEB: 

 

The ECM was a mild run compared to the mean: 

 

There is a definite trend for a fall in temps from D10 to D15, so it looks like that period for London is firming up on HP close to the S/SE. 

 

The wind shows how much the 0z GFS op was an outlier: 

 

The 06z T384 chart is a lot closer to the 0z mean: 

 

A cool settled Christmas Day in the south looking promising from GFS/ECM at the moment.

[TonyH]

Euro high as we know from the past seems to be stuck down with super glue and can last for weeks. Doesn't look like it will be going anywhere soon either. The five day forecast here from the gfs shows a couple of surprising chilly days which looking at the uppers doesn't quite add up. So I thought about inversion setting in but there's too much wind so I suspect the actual days will be milder than shown. The days in question are Tuesday and Wednesday. The Met have it much milder. 

Does n't add up to me either PIT - a mild week for most I would say with an average day or so mid week for the east.

Edited December 8, 2013 by TonyH

[IDO]

Does n't add up to me either PIT - a mild week for most I would say with an average day or so mid week for the east.

 

Bristol forecast temps from ECM: 

 

 

The mean high for that area is 7c: 

 

Average days but mostly mild and some balmy (+5c).

Edited December 8, 2013 by i'm dreaming of...

[cooling climate]

Perturbation 16 offers something much more seasonal but in all probability

very unlikely.

Since the mood for winter weather lovers is pretty low at the moment here is

a dream beast from the east chart taken last April for Jan 14 from cfs.

Who knows something similar to this could be awaiting us in the new year.

[nick sussex]

No change today with variations on the same underwhelming  theme for coldies, either a moister sw'erly flow as low pressure gets in closer to the UK or drier with high pressure edging a little further north.

 

Both though have the same overall NH pattern, high pressure to the south, low to the north, strong PV and flat upstream pattern. In terms of the GEFS ensembles you will always find the odd solution that promises something a little better but I'd ignore any of these until the pattern is shown to change within the higher resolution within T240hrs.

 

My horror rating has now reached critical proportions of 9.5/10! There is no zonal reset here, the best we can hope for is that the models edge the jet further north to at least keep things mainly dry and a better chance then of some colder surface air moving in from the continent. If low pressure gets modelled further south you'll never get it far enough south to even get a PM flow in and will just end up with zonal mild sw'erlies and wet!

 

Its a dismal set up for real cold, we can just hope that the models shorten this underwhelming spell but we need to see a big change in the PV and the pattern across the USA.

 

In recent winters each time the models have tried to pull in this type of pattern, its been shortened with things looking better however the background signals are not great at the moment.

 

We'll see over the next few days whether they've overreacted or whether this is indeed going to be an extended spell of milder conditions especially the further  north you are.

[karyo]

No change today with variations on the same underwhelming  theme for coldies, either a moister sw'erly flow as low pressure gets in closer to the UK or drier with high pressure edging a little further north.

 

Both though have the same overall NH pattern, high pressure to the south, low to the north, strong PV and flat upstream pattern. In terms of the GEFS ensembles you will always find the odd solution that promises something a little better but I'd ignore any of these until the pattern is shown to change within the higher resolution within T240hrs.

 

My horror rating has now reached critical proportions of 9.5/10! There is no zonal reset here, the best we can hope for is that the models edge the jet further north to at least keep things mainly dry and a better chance then of some colder surface air moving in from the continent. If low pressure gets modelled further south you'll never get it far enough south to even get a PM flow in and will just end up with zonal mild sw'erlies and wet!

 

Its a dismal set up for real cold, we can just hope that the models shorten this underwhelming spell but we need to see a big change in the PV and the pattern across the USA.

 

In recent winters each time the models have tried to pull in this type of pattern, its been shortened with things looking better however the background signals are not great at the moment.

 

We'll see over the next few days whether they've overreacted or whether this is indeed going to be an extended spell of milder conditions especially the further  north you are.

Very realistic post. I think with the situation in the stratosphere unlikely to improve much this month we can write off the first half of winter off!

 

Karyo

[Continental Climate]

Perturbation 16 offers something much more seasonal but in all probability

very unlikely.

pert 16.png

Since the mood for winter weather lovers is pretty low at the moment here is

a dream beast from the east chart taken last April for Jan 14 from cfs.

jan 14 on 16.04.13.png

jan 14 on 16.04.13 850.png

Who knows something similar to this could be awaiting us in the new year.

That beast chart is the pinnacle of easterlies that would be once in a lifetime -18 850's