Model Output Discussion 17th Dec.2013-12z onwards.

[nick sussex]

I'd like to see the low near the UK further south and east at 144hrs because that will want to get pulled n/nw as the big low out of the ne USA phases with it, there are some huge differences between the ECM and GFS but at least they both trend towards more colder potential.

 

The ECM at 192hrs is good but will the energy separate from Greenland?

 

No separation and the energy heads north, no middle ground solutions here, that damn shortwave!

Edited December 24, 2013 by nick sussex

[Captain Shortwave]

Bah the ECM Christmas Grinch has appeared

That 1000mb shortwave running north east. That needs to do one on future runs or else you get the HLB but get a SW/NE jet running underneath it and into Europe.

[swfc]

close but no cigar but still a better run and trending in the right direction

[SMU]

Until the jet goes NE on the ECM we will not tap the cold air from the East- WHy because a NE jet in the atlantic will curve SE over Scandi thus pulling any low south-

 

Another shot of atlantic ridging at 240-

 

 

S

[nick sussex]

Bah the ECM Christmas Grinch has appeared

That 1000mb shortwave running north east. That needs to do one on future runs or else you get the HLB but get a SW/NE jet running underneath it and into Europe.

Very frustrating as the pattern upstream at T144hrs over the ne USA was better than the GFS, I think we need a stronger ridge north ahead of that low to delay it and the low near the UK needs to be shallower and further se. It's better than the 00hrs run but this is really an opportunity we need to take whilst the Arctic high is waiting to help.

[EML Network]

Well the ECM makes a tentative ant step in the right direction. problem is that by the time it gets to ''the right direction'' it'll be June.

 

Overall pattern of High pressure to the South and Low pressure to the North, however, remains and you can see how we'd likely end up right back where we started at the beginning of December.

 

Prospects for cold and snow remain as illusive as ever tonight ..for most of us:-(

 

Edited December 24, 2013 by EML Network

[cooling climate]

Very good GFS 12z this afternoon considering what we have had to put

up with so far this winter. I was beginning to wonder when the models

would revert back to showing heights building to the north/northeast

to link up with the Arctic high moving towards Spitzbergen.

The ECM 12z is starting to get to grips with the pattern change by

the looks of things.

[Captain Shortwave]

Very frustrating as the pattern upstream at T144hrs over the ne USA was better than the GFS, I think we need a stronger ridge north ahead of that low to delay it and the low near the UK needs to be shallower and further se. It's better than the 00hrs run but this is really an opportunity we need to take whilst the Arctic high is waiting to help.

At least we have some options though. FI has to be around T96 at the moment as the GFS/ECM deviate wildly from after the Friday storm eases away. Add to that the UKMO which is having none of this whatsoever.

Unfortunately for many on here who might be spending Christmas with family and probably won't be logging in at all. Tomorrows runs will be huge as how things pan out at days 4-6 will have a big impact on the conditions we receive around the turn of the year.

Standard 

The Atlantic ridge route suggested by the GFS looks a lot safer, as you can develop the high and split flow in situ which will pretty much delver the goods for the UK. The ECM route round the back is dangerous as you require a favourable upstream pattern. 

GFS is a straight yes or no. ECM might be a case of winning the battle but losing the war. 

Edited December 24, 2013 by Captain shortwave

[bluearmy]

ECM up until semi reliable timeframe is decent for a cold solution. . Finally an ecm op run heading towards its ens story.

[nick sussex]

I think we need to see this type of set up to be guaranteed success, the low near the UK needs to dig more se and we need a stronger ridge ahead of the pesky low moving out of Canada.

 

 

Having said all this even if the ECM or GFS did that we still have the UKMO which is flat and basically going nowhere at T144hrs, we've been here before with the UKMO, it may never have a cold T144hrs solution that verifies against the ECM and GFS but you can bet your last pound that its milder solution at that timeframe hangs over this thread waiting to harpoon hopes.

 

Until that comes on board with at least some potential I'd put the sledge order on hold!

[Methuselah]

No more than 30 degrees NE ideally .

 

S

http://www.meteociel.fr/modeles/ecmwf/runs/2013122412/ECH1-168.GIF?24-0

ECM going via the Scandi back door-different to the GFS

S

 

Well, it would help if you explained what you meant when you said it, Ste? But thanks for that! 

[Grimsby Snow Lover]

Following on from a pretty pleasing GFS 12Z run (if colds your thing) the latest AO forecast looks good to me with most members going negative.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

The NAO could go either way http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif.

Merry Christmas everyone.

[Summer Sun]

Following on from a pretty pleasing GFS 12Z run (if colds your thing) the latest AO forecast looks good to me with most members going negative.http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gifThe NAO could go either way http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif.Merry Christmas everyone.

 

Quite a change in today's NAO update compared to yesterday its gone from negative to natural

[Iceaxecrampon]

 

Best chart for any ppn (*Will be back "home" for that) - talk about clutching at... but you have to gain altitude to benefit - interesting travel back from Grasmere this afternoon Ghyls and Becks at real capacity drove back in to a sleet shower in Lancashire  - sorry to hear about the unfortunate but avoidable loss of life in the Rothay.

 

Best wishes to all the community and its personalities on here cold or blowtorch...!

 

Ian

[Gibby]

Good evening. Here is the Christmas Eve report on today's NWP midday output.

 

All models show an intense Low close to NW Scotland moving slowly North and filling slowly. A rather cold SW flow covers the UK with most showers over the Christmas period hugging coastal areas facing South and West and it maybe that many inland areas stay largely dry and bright with some sunshine by day with a touch of frost by night. Where showers do occur they could be heavy and wintry over any high ground above 250 mtrs. By the end of Boxing Day a new storm is shown to move in off the Atlantic with further very strong winds and heavy rain commencing 48 hrs from now in the SW and spreading quickly NE to all areas overnight. On Friday the rain will clear East to sunshine and showers in a strong WSW wind again and snow will fall from these showers too over the hills in the North. This showery theme then continues over next weekend with the showers dying away on Sunday as a weak ridge is shown to cross from the West.

 

GFS then shows another storm system to take us up to the New Year with yet another Low pressure coming into the UK from the West. This then fills in situ over the days up to the New Year and into 2014 itself with showers or outbreaks of rain, falling as snow over the hills in decreasing winds over the period. Low pressure then pulls down from the NW and settles towards the SE of Britain by the end of the run with a change to much colder and unsettled weather with sleet and snow becoming much more prominent should it verify in a cold and blustery NE flow with High pressure having built North through mid Atlantic.

 

UKMO tonight shows next Monday with a new Low pressure in the Central North Atlantic with a WSW flow over the UK. Troughs in the flow will continue to bring rain at times and it will fall as snow for a time over Northern hills. In the South it looks somewhat milder later.

 

GEM shows a continuing flow of Low pressure moving West to East across Britain from a weeks time though with less explosive force as recently. There would be spells of rain and showers for all but it should be less windy than recently.

 

NAVGEM closes it's run with Low pressure still well in control with centres close to or over the UK with plenty of wind and rain for many areas under temperatures close to average.

 

ECM keeps the unsettled and changeable theme going later in it's run though the charts look far less stormy than recently. Nevertheless there will be troughs crossing East in the Westerly flow with rain or showers at times in temperatures never far from average though it may turn rather cold towards the end of the run in a more NW flow.

 

The GFS Ensembles show that the weather remains changeable for the next 10 days. There is some support between it's own members of a cool off at the end of the run when it would become rather less wet though the operational is at the extreme end of this scenario.

 

The Jet Stream shows the flow remaining close to or just to the South of the UK tonight keeping the UK under a trough throughout the run meaning Low pressure close by. Evidence of a build of pressure in the Atlantic is shown towards the end of Week 2.

 

In Summary tonight the weather stays on an unsettled track for a good while to come. After a relatively quiet and showery Christmas another powerful storm looks likely later this week and the weekend before less stormy conditions are trended thereafter. Nevertheless there seems little evidence of any settled conditions with further rain expected off and on throughout the next few weeks with the saturated ground having little chance to recover. GFS does show some signs of a pattern change late in it's outputs supported by some of it's own ensemble members. However, I feel that we need such a trend developed on over the coming days and given more cross model support once such a change comes within all models time range.

 

A Very Merry Christmas To You All

Edited December 24, 2013 by Gibby

[ANYWEATHER]

Tbh, slim pickings for anyone who wants proper Wintry weather nationwide from the gfs and ecm, little change than previous days! The Atlantic is is full control with the Polar vortex low and the Azores high funnelling a serious strong jet stream towards the uk enhancing low pressure systems to become very deep and stormy! Of course with some rPM air with these systems snow will fall in the usual places. Well at least Christmas day and Boxing day will give us a rest from the stormy weather with a few folk waking up to a White xmas tomorrow .with Boxing day staying chilly as well so at least the weather feels festive during the next couple of days....    The charts below indicate at the unreliable time frame @T+240  from gfs and ecm showing similar conditions....

[ricey076]

A member and lurker for many a year.. Merry christmas to all

[syed2878]

differents with ecmf and gfs as close as 120h though the ecmf looks good from 144h onward haven't we been here before? This winter. As for the ecmf32day output before the start of winter it was going for nb for lot of dec of course that didn't come off ither. Seasons greetings to every1 and all the staf at nw.

[SMU]

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.php?run=12

 

Quite a few more snow spikes after day 11 & a good general trend with the mean @ 3c.

 

S

[East_England_Stormchaser91]

This time last year we were in a similar pattern as to what we are now, Atlantic train with stubborn heights to our S. Give it until mid-late jan when I think we will have seen or will see quite a change in pattern.

[carinthian]

seemingly you have completely disregarded the latest ec32, and binned that evolution? Because at face value, it does not show what you suggest.a touch misleading, and false hope is no hope at all. I'm not saying it wont evolve, but where is the evidence to corroborate this vision? Most lrm I look at keep a fairly zonal theme.

I have no access to ec32 and no false hope. It is based on a good source of information who provided our excellent portal service. 

The zonal theme will peak over the Christmas period with the thermal gradiient at its greatest and as previous posted we expect the jet to continue to move southwards with increasingly cold theme taking hold in January.

[bluearmy]

I have no access to ec32 and no false hope. It is based on a good source of information who provided our excellent portal service. 

The zonal theme will peak over the Christmas period with the thermal gradiient at its greatest and as previous posted we expect the jet to continue to move southwards with increasingly cold theme taking hold in January.

 

which is backed up completely by the ecm ens. again the 12z suite is consistent. if anything the low anomolys over europe increasing in two weeks time in conjunction with the jet sinking south on a nw/se axis.  would be surprised to get to the 10th jan without a snow event in the northern half of the uk. that could come further south but going to play safe for the time being.  given that the naefs anomolys are beginning to sing the same tune towards the end of its 12z run, confidence in this evolution is growing.

[Jason M]

I have no access to ec32 and no false hope. It is based on a good source of information who provided our excellent portal service. The zonal theme will peak over the Christmas period with the thermal gradiient at its greatest and as previous posted we expect the jet to continue to move southwards with increasingly cold theme taking hold in January.

Of course had you access to EC32 you presumably would have discounted it anyway on the basis that its rubbish ;-)

[UV-RAY]

I have no access to ec32 and no false hope. It is based on a good source of information who provided our excellent portal service. The zonal theme will peak over the Christmas period with the thermal gradiient at its greatest and as previous posted we expect the jet to continue to move southwards with increasingly cold theme taking hold in January.

Take no notice carinthian , your updates from your source have been spot on thus far. I think some are just on the wind up Edited December 24, 2013 by Sceptical Inquirer

[carinthian]

which is backed up completely by the ecm ens. again the 12z suite is consistent. if anything the low anomolys over europe increasing in two weeks time in conjunction with the jet sinking south on a nw/se axis.  would be surprised to get to the 10th jan without a snow event in the northern half of the uk. that could come further south but going to play safe for the time being.  given that the naefs anomolys are beginning to sing the same tune towards the end of its 12z run, confidence in this evolution is growing.

Well put Bluearmy. A change is a coming.albeit slowly. Confidence is 60 % for cold evolution in Europe to take over during January and snowfall could be signicant.

 C