Model Output Discussion - 26th December - 1st January

[Bobby]

Well this is a more interesting chart on the op than we've seen lately

Get that high further north and bingo, easier said than done though. A few of the ensemble runs have been toying with that idea however.

There's a lot more northern blocking showing on the ensembles lately also.

Otherwise wet and windy for the forseeable future.

[Robbie Garrett]

This is in interesting ensemble, P8 - not sure what color it is - reminds me of 2010 all over again! I've just had a look at the GFS again, after 120hrs it doesn't look like the high shifts until further in the run (FANTASY ISLAND)

She's a lonesome ensemble, but it goes to show that something could potentially happen!

11-13th Jan onward!

Edited December 31, 2011 by phil n.warks.
removed copy of deleted post

[A Winter's Tale]

I am beginning to feel that this winter won't bring an event that we've seen in the past 3 winters. Brief wintryness in the north is the story with the polar maritime incursions. The end of the GFS run is awful and this looks like continuing for a bit longer. I hope that between now and mid January, we do see the breakthrough that we've all been waiting for with the models. But my gut feeling is that we'll have to wait until sometime between mid January and Early February in order to see the developments that we want to see. And still, it's not too late as that could result in a decent February so in terms with developments in the models for a cold snap to remember then I would feel that we've got to early February for that break. If not, then I feel that Mid January to Mid February may see the Atlantic slow down at some point which could see one or two cold snaps with a bit more to offer than the polar maritime topplers. But unfortuantly for some, my gut feeling is that it's going to be difficult for many south of Manchester to see any snow in the remaining winter months. Then there's Spring, but I certainly do feel that quite a few on here may have to wait two years to see snow/lying snow.

[lorenzo]

This P8 evolution is being mooted as the Holy Grail of synotics, I guess folk wont be happy until the Atlantic train is shut off and shut down.

It could easily topple and leave us in the limpet high scenario for the rest of Feb / March... the determination for fixed patterns over the end of 2010/11 is a definitive trend here.

Eyes NE for cold this time perhaps..

[feb1991blizzard]

This is in interesting ensemble, P8 - not sure what color it is - reminds me of 2010 all over again! I've just had a look at the GFS again, after 120hrs it doesn't look like the high shifts until further in the run (FANTASY ISLAND)

She's a lonesome ensemble, but it goes to show that something could potentially happen!

11-13th Jan onward!

Yep, although we need to see more ens trend like it over the next few weeks, its certainly not going to be a quick transition if it happens, just a waiting game albeit a very frustrating one at the moment.

[A Winter's Tale]

This P8 evolution is being mooted as the Holy Grail of synotics, I guess folk wont be happy until the Atlantic train is shut off and shut down.

It could easily topple and leave us in the limpet high scenario for the rest of Feb / March... the determination for fixed patterns over the end of 2010/11 is a definitive trend here.

Eyes NE for cold this time perhaps..

What are the developments in the Stratosphere and the PV. Is there any suggestion of a warming? And surely any decent events regarding the PV and stratosphere would also increase the chances of Northern Blocking?

[lorenzo]

What are the developments in the Stratosphere and the PV. Is there any suggestion of a warming? And surely any decent events regarding the PV and stratosphere would also increase the chances of Northern Blocking?

AWT - best look at the Strat thread, although warming can occur there are many different outcomes, some are pre-disposed to colder set ups, some are less favourable.

I see just now that the rampant AO / NAO and PV are slowly being simultaneously eroded leading to a colder pattern emerging, this is science fact, in particular with relevance to the NAM ( NAO/AO) these types of patterns cannot be sustained forever. DS on AMwx hs a detailed thread on this.

Other factors disturb this being a clinical and precise forecast for composites - La Nina wavering leading to no definite pattern for standard MJO composites - ENSO CPC predict similar to 84/85, GLAAM inflections show a more evident El Nino pattern.

A currently weak MJO moving through cycles to stage 2 around 10th Jan may see the model flip sometimes alluded to, composties are difficult to decipher due to the PV modelling.

It is moving forward for cold I feel the trends in the main TC AO NAO evidence this. As much as the early 90s winters analog there are strong pattern matches to some superb winters in the mid 80s too..

The russian high which has been the main 'stayer' along with this azores/bartlett set up is the one I am looking for to see where it elongates NNW, this and the Pacific ridging.

Edit there is not such word as aklong ; meant along.

Edited December 31, 2011 by lorenzo

[Kentish Man]

Interesting to see the 18z operational run is the coldest in respect of the 2m temperatures for Kent post 180 on the GEFS ensembles. In fact it is something of an outlier at that timeframe with most runs way milder. The question is whether some new signal is hinting at a possible end to the zonal conditions or will we be back to square one tomorrow.

[Cheshire Freeze]

Evening all

I fear that this winter is now set in stone as a pre 2007 special. I had hoped to see changes in the output towards the new year but as things stand only a few wayward ensemble members portray anything interesting RE cold and snow.

A large chunk of January looks to be wasted now and our last hopes hang on later in January and Feb when we have a strengthening sun to contend with. Not ideal.

[Dale Leigh_6487]

for god sake it's december all theses negative posts . winter will strike mid jan till march wait and see .

[Cheshire Freeze]

for god sake it's december all theses negative posts . winter will strike mid jan till march wait and see .

Based on what evidence?

As far as I can see with the modelling, the synoptic pattern is one which is 'locked' zonal for the time being; a pattern which has the potential to be locked in for another 2 weeks. That brings us to mid Jan, by which time there will be lengthening daylight and posts about snowdrops and daffodils appearing......I prefer snow to fall and stick around- that's difficult to acheive at this altitude on the shortest day, let alone as we get closer to spring!

[Zakos]

for god sake it's december all theses negative posts . winter will strike mid jan till march wait and see .

Exactly. People seem to forget that jan and feb are on average colder than December. YES the first half of jan is "set in stone" in terms of no northern blocking. But, the PV is increasingly being modelled to weaken, Maybe even split. Beyond mid/late jan, there is all to play for, especially in feb which IMO has the potential to be a very severe month. People who write off winter before we're even half way through it are barking mad. Seeing as I saw 4 days of falling snow/ sleet, and 2 days of lying snow, even though dec was milder than average, I would be very, very suprised to not see at least At least a few days of lying snow. Depending on when the cold arrives will determine weather the winter is colder or milder than average overall.

[Cheese Rice]

Your contradicting yourself Crewe. How can winter be set in stone yet the pattern has the potential to be locked in for another 2 weeks? February holds the record for the coldest CET, which suggests to me there is far more potential for cold and snow in Feb than in any other month. The Atlantic is typically at its quietest. And if we do see the stratospheric warming aided with a quieter Atlantic we could see a severe cold spell.

Edited December 31, 2011 by Cheese Rice

[Zakos]

Based on what evidence?

As far as I can see with the modelling, the synoptic pattern is one which is 'locked' zonal for the time being; a pattern which has the potential to be locked in for another 2 weeks. That brings us to mid Jan, by which time there will be lengthening daylight and posts about snowdrops and daffodils appearing......I prefer snow to fall and stick around- that's difficult to acheive at this altitude on the shortest day, let alone as we get closer to spring!

dec on average is Milder than jan and feb because of the colder seas coupled with generally weaker jet stream. in march it is difficult to get lying snow. That is not the case in february at all.

[Mark Neal.]

Even wen February is 1/2 way through, at that point it would be still unwise to write off winter. December and it's bonkers, I know some people are inpatient but it's what expected with the unseasonably mild weather some have been experiencing. More zonal weather to come and Northern areas could see some snow, so not a total travesty, just yet anyway

[Zakos]

Correct me if I'm wrong, But doesn't the NH snow cover extent reach its maximum on average in February?

[Cecil Hogmanay Melchett]

^{To be fair CC is correct in some asdpects,yes deep cold is achievable in Feb but the strength of the sun becomes a major player by the 2nd week in Feb.}

^{To counteract that the sea should be cooled down nicely by this stage of the winter(although with the winds prevailing south westerlies this 'winter' they wont be that cool),another positive for Feb cold spells is the continent is usually colder by Feb although again this year its been very mild across europe as a whole,courtesy of that gosforsaken euro high which has stuck like a limpet to southern central europe.}

^{Anyway,the optimum time as far as im concerned is round about now ie between say 20th dec and 20th jan,that period is going to produce pretty much nothing in the way of high lat blocking and i think this is a big disappointment.}

Edited December 31, 2011 by happy days

[Cecil Hogmanay Melchett]

Well yes, thanks but no thanks GFS00Z.

A zonal-fest to match the horror's of 1988/89 im afraid-not seen a vortex as intense as that monster for some time!!

UKMO 00Z is also poor but offers the potential of a UK high down the line.(Only viewed wz format but it can't be as bad as GFS at any rate).

In short We need to see some drastic changes somewhere somehow upstream..

[Duane S.]

Well yes, thanks but no thanks GFS00Z.

A zonal-fest to match the horror's of 1988/89 im afraid-not seen a vortex as intense as that monster for some time!!

UKMO 00Z is also poor but offers the potential of a UK high down the line.(Only viewed wz format but it can't be as bad as GFS at any rate).

In short We need to see some drastic changes somewhere somehow upstream..

Yep can't argue that the gfs 00z is pretty dire. The ECM offers up an interesting 10 day chart with a WAA surge NE towards Scandi. Where we would go from there would be up for debate I think.

[The Northern Ramper]

Based on what evidence?

As far as I can see with the modelling, the synoptic pattern is one which is 'locked' zonal for the time being; a pattern which has the potential to be locked in for another 2 weeks. That brings us to mid Jan, by which time there will be lengthening daylight and posts about snowdrops and daffodils appearing......I prefer snow to fall and stick around- that's difficult to acheive at this altitude on the shortest day, let alone as we get closer to spring!

You don't see any snow anyhow so it doesn't matter

[Snowmad79]

Well yes, thanks but no thanks GFS00Z.

A zonal-fest to match the horror's of 1988/89 im afraid-not seen a vortex as intense as that monster for some time!!

UKMO 00Z is also poor but offers the potential of a UK high down the line.(Only viewed wz format but it can't be as bad as GFS at any rate).

In short We need to see some drastic changes somewhere somehow upstream..

Not particularly bothered what the GFS operational actually shows anymore with it consistantly riding high above other ensemble members at the higher end of temps etc for the past 3 months.

Today is actually the first day that I've seen the Operational more stable amongst the cluster members in the ensembles and actually keeps things around the -5 hpa mark with little in the way of erratic ups and downs compaired to alot of the previous runs, however that is for the north. When you look at london ens its back to its silly mild outlier.

Edited December 31, 2011 by phil n.warks.
removed gen.comments-stick to mod.disc please.

[Duane S.]

Yep can't argue that the gfs 00z is pretty dire. The ECM offers up an interesting 10 day chart with a WAA surge NE towards Scandi. Where we would go from there would be up for debate I think.

EDIT: In retrospect maybe a 'WAA surge' is a little misleading but certainly a linkup of sorts between the Azores and the Russian HP (according to the ECM anyway). Now if that were to coincide with a weakening Atlantic and warming in the strat was taking its toll on the vortex it could get interesting. If we could pull out some sort of undercut from that scenario hat it could be an almightily impressive one!

Highest above the mean so far this winter at 10 hPa, this may have little or no effect of course but at least it's a positive going into 2012...

Edited December 31, 2011 by s4lancia

[Snowmad79]

EDIT: In retrospect maybe a 'WAA surge' is a little misleading but certainly a linkup of sorts between the Azores and the Russian HP (according to the ECM anyway). Now if that were to coincide with a weakening Atlantic and warming in the strat was taking its toll on the vortex it could get interesting. If we could pull out some sort of undercut from that scenario hat it could be an almightily impressive one!

Or it could end up ala autumn:

Especially if that russian high continues to be sucked west into europe and the high progged to the SW of the UK merges with it. (on the ecm 00z T192 - T240)

Edited December 31, 2011 by Snow Time 79

[Duane S.]

Or it could end up ala autumn:

Especially if that russian high continues to be sucked west into europe and the high progged to the SW of the UK merges with it. (on the ecm 00z)

Absolutely agree. Without a few things going our way it could act to reinforce heights to our south, like they need it right now!

[snow drift]

Absolutely agree. Without a few things going our way it could act to reinforce heights to our south, like they need it right now!

This looks the most plausible way to me and backed by the meto currently. Not what I would want but I feel this is the path we are on.