Model Output Discussion; into 2015

[Severe Siberian icy blast]

return of the great double act time... lol..

 

see i disagree with this.... why?... because the building blocks that first raised their heads in early november are gone, northern blocking - gone, eastern blocking - gone, western blocking (that was expected to produce a pre crimbo freeze, then a post crimbo freeze) - gone . (yes some of us got a cold snap)

as i see it theres no sign of any building blocks, the noaa charts have a strong westerly upper flow for the next two weeks, the signals for blocking from any quarter have decreased and are now practically zero. so surely the trend is away from any cold, not towards increasingly wintry?...

of course if you take the deepest fi charts as evidence, then ok... but until charts like the current gfs 00z predicts reach the reliable/ semi reliable timeframe then they cannot be taken seriously.

sorry, pc awaiting re-formatting  unable to download and post charts.

I wholly agree . High pressure over Siberia in November has been replaced by low pressure , and I personally feel that's been a massive factor in what's gone wrong so far. Every bench mark that was made during October/nov , has been reversed , it's certainly made me sceptical regarding how credible some theories are .

[knocker]

Something along these lines perhaps?

 

gensbcnh-13-1-360.png

 

 

Happy new year everyone.

 

No more like this

[gottolovethisweather]

Happy New Year all.

 

My brief analysis of all available outputs indicates very little prospect of prolonged cold and lingering lowland snow up to mid-January, according to current modelling, this can of course change quite rapidly once a new signal is picked up. Air Temperatures don't ever get much below Average by daytime with some mild to very mild days thrown in, best chances of Frost in the South and East of the UK. Wet to very wet at times towards the West and Northwest, drier towards the far South. With a chance of some rain everywhere evrye other day or so, a distinct lack of wintriness except where the NH Jet tilts NW to SE, however it rarely is forecast to do so during the next 14 days.

 

A long haul to cold but some active weather about, more especially for parts North and West, a drier signal on the whole nearer the South due to Euro High influence.

Edited January 1, 2015 by gottolovethisweather

[johnholmes]

Happy New Year everyone, how many have already broken the NY resolution?

 

Re the weather then the link below shows the main upper air pattern for 6-10 days with NOAA supporting this idea out to day 14.

 http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Expect more than 1 pretty deep low in the 6-15 day time scale, generally passing NW of the UK but there is a risk of one being somewhere over Scotland on its track. Broadly westerly upper flow with relatively minor upper troughs with a surface feature beneath giving milder conditions ahead and colder conditions behind it. There is as yet no sign on the 8-14 NOAA of anything major changing. Rest assured if/when it does I will drop it in here.

[Eugene]

Increasing trend on GFS 06Z ensembles of an euro trash high just to our south in 8 to 10 days time, could be a very mild dry period for southern UK.

[ANYWEATHER]

Morning all, and a Very Happy New Year to everyone! Well it may be a different year, but it does look like the weather will continue the alternating cold and mild spells as we saw in December. So plenty of weather to talk about,  but any wintry weather does look confined to Northern areas in picticular, although the south may see some wintry flurries at times especially on high ground given enough Polar maritime air in the mix, and there is likely to be some fleeting quieter  spells allowing for some  limited frost at times. So a very mobile situation, although not without interest for the die hard cold fan

Edited January 1, 2015 by ANYWEATHER

[Frosty.]

Looking through the GEFS 00z perturbations, I was struck by P5..p5 is the pattern change I want.. polar front jet heading for a holiday in north Africa, Azores high put back in its box, beyond this chart the cold would intensify...i want this chart with an extra large cherry on top..yeah i'm greedy and biast for snow and frost I admit it :- ) snow fest UK 2nd half of Janvier.don't rule it out.

Edited January 1, 2015 by Frosty.

[bluearmy]

In typical NWP fashion, the 06z suite is further north than the 00z with the Azores -euro ridge no longer being substituted in week 2.

[IDO]

In typical NWP fashion, the 06z suite is further north than the 00z with the Azores -euro ridge no longer being substituted in week 2.

 

Yes the long wave pattern is pretty much set in stone though how the PV interacts within the pattern is fluid so I wouldn't like to predict the jets axis or latitude for a few days for week 2. the D12 ensembles:

 

[Timmytour]

Looking through the GEFS 00z perturbations, I was struck by P5..p5 is the pattern change I want..with an extra large cherry on top..yeah i'm greedy and biast for snow and frost I admit it :- )

 

It's always perturbation no 5 it seems!    wonder if it will snap up the "Perturbation Of The Year"  when the annual Netweather Model Awards are handed out?

Seriously, and i apologise because I'm sure this question will have been asked before, but is there any records kept of which perturbations end up beng the most accurate and which, if any, are renowned for successfully picking up early signals (even if they don't go on to be successful with the molddeling on them)

[shaky]

In typical NWP fashion, the 06z suite is further north than the 00z with the Azores -euro ridge no longer being substituted in week 2.

is that good or bad!!

[bluearmy]

is that good or bad!!

Bad if you want cold zonal. Good if you want more settled zonal interludes in the south.

Incidentally, I wonder what the ECM ens that takes london wind speeds above 20m/s on the 8th looks like!

[nick sussex]

It's always perturbation no 5 it seems!    wonder if it will snap up the "Perturbation Of The Year"  when the annual Netweather Model Awards are handed out?

Seriously, and i apologise because I'm sure this question will have been asked before, but is there any records kept of which perturbations end up beng the most accurate and which, if any, are renowned for successfully picking up early signals (even if they don't go on to be successful with the molddeling on them)

That's a good question and I don't ever remember anyone asking this before. As we know they tweek each ensemble member so one would think that they would likely have data for which ensemble ended up being the closest to what verified, then I would think they would perhaps use that info to try and both improve the rest of the ensembles aswell as the operational run.

 

The issue is though complex because depending on the type of pattern a particular ensemble member may prove to be better so its not just one member but this differs with the type of synoptics on show. It would be interesting to see for example which member/s deal better with northerlies, easterlies etc. What slight tweek at the start helps to reduce the error at longer range?

[Frosty.]

It's always perturbation no 5 it seems!    wonder if it will snap up the "Perturbation Of The Year"  when the annual Netweather Model Awards are handed out?

Seriously, and i apologise because I'm sure this question will have been asked before, but is there any records kept of which perturbations end up beng the most accurate and which, if any, are renowned for successfully picking up early signals (even if they don't go on to be successful with the molddeling on them)

What I post is an antidote to the gloom and doom misery from some on here...nuff said.

[TEITS]

wont it?... this morning theres nothing but average on the cards for the next 10-14 days in any model run. the noaa 500bm are consistent in their expectation of a strong westerly upper flow. any ridges will be transitory. looking pretty wet and windy for the first half of jan.. with alternating mild/cold blasts between systems.

no sign of settled, no sign of fog (other then low cloud/hill fog), no sign of deep cold in fact after the various 'building blocks' over the last two months have failed to bring a decent widespread cold spell (note widespread - not everyone had the mini freeze i did!) the synoptic pattern this morning looks a million miles away from any cold evolution. 

 

yeah i know, this wont be popular, but as things stand its accurate?

I stand by my post last night. Note the word MILD & zonal.

 

What is clear to me is slowly the pattern will change from mild, zonal with brief colder spells to a colder zonal period. in around 10 days time. I have just seen Ian F post referring to a more NW,ly flow in the longer range.

 

Another trend I am noticing, more so on the 0Z GFS/GFSP is the polar vortex to split around mid Jan with one lobe across Siberia and the other W of Greenland. Now ideally we want the lobe W of Greenland to be weaker and further W and this in my opinion remains possible. As a result of this a colder N,ly flow becomes possible.

 

So in summary the unsettled, mild weather will eventually be replaced by unsettled colder NW,lys in around 10-15 days time. Thereafter an even colder N/NE,ly flow for the 2nd half of Jan.

[Timmytour]

What I post is an antidote to the gloom and doom misery from some on here...nuff said.

Frosty.... i meant no offence, far from it.  I love your posts and the optimism in your posts is always in my heart....even if sometimes i find it difficult to get into my head

And the perturbations fascinate me....I often forget about them until someone like yourself puts one up every now and then. I honestly do believe that all it takes is one to show us the kind of stuff we're after to generate a real for some optimism at least.

[offerman]

Happy New Year all,

I am a huge fan of cold frosty or snowy weathet but im a realist to and the next two weeks looks zonal with the odd brief cooler day as cooler air mixed up in the zonal originating from Canada/Greenland straight.

I my days in the 1980s i do remember a couple of cold snow February's to so all is not lost, keep the faith!!

[Jason M]

I think Fergies point about there being record levels of confidence over the next week or so is an interesting one. I actually think that doesn't surprise many in here this morning and is something many of us have picked up on over the last week. Hence many have been saying forget the first half of January, even with several days of December left to go. followed by lots of arguing from people who haven't maybe noted this.

The consistency in the ensembles had been absolutely emphatic. I certainly never recall such a strong signal in my many years of interest. To back up mushy here, the charts have basically being saying to us that we have absolutely zero chance of any northern blocking. Even last year there were some outriders. It's been literally days since I've seen a genuinely cold ensemble member (ie something showing other than just a PM flow). Not yet looked through 06z set though, but I'd imagine same result.

A good example is the ridging attempt at about day 5. Normally a few GEFS would develop something like that, but I don't think I've seen one ensemble do anything over than collapse the ridge.

The next issue will be of any PM shots, GFS in particular tends to overplay the 850s in these situations meaning that when the event arrives it's often a rainfest for most. The one thing in our favour though is that a NW in mid January is likely to be a little colder than the mid December equivalent.

Maybe this years lesson is not to hang on the strat outputs so much. That's not to say we should ignore them, but maybe just treat them as a factor to be taken on board rather than 'the only driver' of our weather. That def is not a criticism of anyone as even the strat guys have repeatly warned that nothing is certain.

Anyway, happy new year everyone, and let's all hope that we get our easterly at some point :-)

Edited January 1, 2015 by Jason M

[Fozfoster]

Happy New Year everyone, how many have already broken the NY resolution?

 

Re the weather then the link below shows the main upper air pattern for 6-10 days with NOAA supporting this idea out to day 14.

 http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Expect more than 1 pretty deep low in the 6-15 day time scale, generally passing NW of the UK but there is a risk of one being somewhere over Scotland on its track. Broadly westerly upper flow with relatively minor upper troughs with a surface feature beneath giving milder conditions ahead and colder conditions behind it. There is as yet no sign on the 8-14 NOAA of anything major changing. Rest assured if/when it does I will drop it in here.

ME....... i said i wouldnt look at the MOD thread until end of weekend!

PS Happy New Year all.

Edited January 1, 2015 by Fozfoster

[mcweather]

Happy new year to members of the forum coldies /mildies and inbetweenies.

 

For now fast moving interchangeable mildish and coldish periods are showing on the models

 

Hopefully the rest of winter will have something to keep everyone happy, and I do think that will be the case. The first half January is very often a stormy period anyway so best just for those seeking widespread cold and snow away from northern hills to sit back and let it blow itself out. There are some back ground signals that hint a somehwat  more wintry pattern later in the month and  feb could  bring anything. That's the wonder of this subject that we are all so wrapped up in.

 

So just relax and enjoy it we can't change it no matter what the models show.

[Frosty.]

Frosty.... i meant no offence, far from it.  I love your posts and the optimism in your posts is always in my heart....even if sometimes i find it difficult to get into my head

And the perturbations fascinate me....I often forget about them until someone like yourself puts one up every now and then. I honestly do believe that all it takes is one to show us the kind of stuff we're after to generate a real for some optimism at least.

Cheers, I get a bit carried away but I'm just desperate for a wintry pattern change, the signals are good, I agree with teits and I like the sound of what fergieweather is hinting at with high pressure eventually further west with a trough to the NE. I really want to see the Azores high displaced further sw and free up some room for cold attacks from the nw to become more potent with cold air becoming entrenched.

[John Snow]

Cheers, I get a bit carried away but I'm just desperate for a wintry pattern change, the signals are good, I agree with teits and I like the sound of what fergieweather is hinting at with high pressure eventually further west with a trough to the NE. I really want to see the Azores high displaced further sw and free up some room for cold attacks from the nw to become more potent with cold air becoming entrenched.

NW is useless for widespread snow though, with NW sure Scotland, N Wales and the Cheshire gap would do ok but that's it, we need a NE/E to send us into the freezer and give us the deep snow everyone on this forum wants

[I remember Atlantic 252]

NW is useless for widespread snow though, with NW sure Scotland, N Wales and the Cheshire gap would do ok but that's it, we need a NE/E to send us into the freezer and give us the deep snow everyone on this forum wants

 

agree John, NW winds and cold zonality is useless for the south under say 250m asl

[kumquat]

GEM 168 to 240 shows the best we can hope for:

 

Shearing off half of the vortex

 

 

So we get left with Arctic High (reinforced by Siberian ridging) trying to force into Greeny from above. Low heights into Scandi.

Trouble is even at this point we don't get massive cold to our East.

 

Give it 10 days and we shall see.

 

[Jason M]

I'm struggling to remember a NW wind that ever brought snow to London....can't find any archive charts that show NW winds that caused snow in London and the SE?

I'd imagine snow will be restricted to high ground in East Anglia :-)

It's actually not unknown to be fair as if conditions are right showers can filter down to the SE through the infamous 'Cheshire Gap'. Unlikely, but it can happen.