Winter Model Discussion - The Hunt For Cold - 10th Dec

[latitude]

Now is not the time for an autopsy. We have lost IF within the thread. Treat people how you would like to be treated.

Excuse me? I was trying to understand the post. I think I said what you were trying to say, but for some reason you didnt say it. So what if the ensembles turn out differently to someones predicition? This is the weather, everything can change.

Edited December 12, 2012 by latitude

[Tom Jarvis]

Where is gp we need his voice of hope and reasoning

Edited December 12, 2012 by Tom Jarvis

[Frosty.]

Yes - default UK murk - easy.

(my original message had a sizeable portion of sarcasm..... )

......but you never know.

Ian

hi ian, yes i realised that, we all need a straw to clutch right now because the models really let us down but just to rub salt in, they are showing a milder very unsettled outlook which may last 10 days unbroken, beyond that we may get lucky but it's really poor compared to what most of us were hoping for from both the models and the experts on here who truly believed things were going to happen.

I think we need kate bush to burst into song again nick

Edited December 12, 2012 by Frosty039

[Mark Bayley]

I would agree that any notable cold spell this side of xmas, probably new year, would seem unlikely. However i expect that for the most part it will be mostly average, with cooler and milder periods. So some surprise snow falls, especially for those further north, as we flirt in and out of colder air, should not be ruled out.

Ensemble means paint a pretty unsettled picture, although one that is fairly close to average, so no raging mild zonal that was often to familiar in winters past.

There seems general cencenus on progressing the MJO into a higher amplitude phase two, from all three model ensemble forecasts.

Which gives the following composite, lending support to the continuation of unsettled conditions

The core of the PV still looks to be heading to Siberian region, although theres some suggestion that we may get a lobe heading back towards Greenland going by some of the recent long range model output. Despite this the PV should remain fairly weak, with further wave break activity forecast.

Hopefully we soon get some sort of warming event to finish it off! I will be watching the zonal wind and temp forecasts closely over the xmas period. Although not what everyone wanted (snow) the outlook could be far worse. Close to average and unsettled sums the next week or so, although theres plenty to keep an eye on, such as the strat, which may give us hope for something a little colder as we progress past new year!

Edited December 12, 2012 by Mark Bayley

[nick sussex]

Looking upstream across the USA there is good agreement on a flat pattern with shortwaves tracking east.

Because of this we're left with really only one way out of the average set up, that is to get enough energy heading se'wards into France and the Med.

The Russian high can help by throwing a ridge nw towards Scandi, there is however no sign of it moving westwards and hence its very unlikely this will deliver a long fetch easterly.

The critical timeframe is around 168hrs where you must see some energy heading further south to flatten the Azores high and stop it trying to nose ne'wards.

If you're lucky a shortwave runs east further south as it engages the trough to the west of the UK the phase causes the northern portion of that to tilt nw.

Pretty much what the ECM00hrs does from 192hrs. Thats really the only plausible route to some colder shots until there is a change in the upstream pattern.

[Frosty.]

Looking at the latest gefs 6z mean and ecm 00z ens mean, it's clear the russian high is being pushed away east and by the end of the gefs run it's gone. This does not mean we are heading into a long mild spell, it does look milder from friday onwards but notice future periods of cool cyclonic weather which may be cold enough to bring snow into the forecast again, especially for the north and higher ground, no sign of a freeze before christmas though, rather cool/cold and unsettled is about as good as we can hope for this side of christmas.

Edited December 12, 2012 by Frosty039

[Buriedundersnow]

Looking at the ECM ensembles wind direction there is at least some clustering there switching the wind direction to the southeast east or ne.

That would suggest the two solutions, weak pressure rise to the nw or troughing angled se'wards into Europe.

could u plz explain that chart dont know what i'm supposed to be looking at

[Buriedundersnow]

Looking upstream across the USA there is good agreement on a flat pattern with shortwaves tracking east.

Because of this we're left with really only one way out of the average set up, that is to get enough energy heading se'wards into France and the Med.

The Russian high can help by throwing a ridge nw towards Scandi, there is however no sign of it moving westwards and hence its very unlikely this will deliver a long fetch easterly.

The critical timeframe is around 168hrs where you must see some energy heading further south to flatten the Azores high and stop it trying to nose ne'wards.

If you're lucky a shortwave runs east further south as it engages the trough to the west of the UK the phase causes the northern portion of that to tilt nw.

Pretty much what the ECM00hrs does from 192hrs. Thats really the only plausible route to some colder shots until there is a change in the upstream pattern.

if u look at the GFS 06z and the 12z then there is some attempt to link hieghts between the russian high and greenland from sunday onwards and in the way the runs have played out since yesterday i have noticed run by run less shortwave energy trying to make it between scandi and greenland so that link up might come if runs keep upgrading in that area

[nick sussex]

could u plz explain that chart dont know what i'm supposed to be looking at

Thats the ECM ensemble members, for each of those it shows the wind direction through upto 15 days.

So for example those clustering around 90 degrees show a wind direction from the east, 45 degrees from the ne and so on.

[Continental Climate]

Where is gp we need his voice of hope and reasoning

I know its not just you mate but this type of post is grinding on me now!! He could not be posting for a number of reasons it is the run up to xmas after all friends and family and such or work commitments!! He may also just be bored with the current models i know i am!!

Some messages are laughable " where are you GP, why have you foresaken us"? lol

[Buriedundersnow]

Thats the ECM ensemble members, for each of those it shows the wind direction through upto 15 days.

So for example those clustering around 90 degrees show a wind direction from the east, 45 degrees from the ne and so on.

cheers nick thats what i was stuck on where it shows what direction.

well atleast thats a slight positive sign hopefully more will trend that way.

[Snowly does it]

The Russian High getting shunted is the equivalent of hitting reset. We may not enjoy the refreshed outcome.

Have to say things are starting to look ominous for the next period (which is all that really matters). The two consistent things happening on the GFS runs at the moment are Azores ridging but not where we want it (mid Atlantic/Greenland) and a portion of the PV setting up home in Greenland after T240 or so.

Unless and until these two factors start trending differently we will not see cold before the first week of January IMO.

[Buriedundersnow]

i'm not sure with this but maybe the more knowledgable or one of the mods can help me out here.

i'm sure i read i one of gp's post (i'm sure it was him anyway) that once the pv has moved to siberia it would encourage the russian scandi high to move toward greenland. plz can someone tell me if i am right there,

now with previous runs constantly showing less shortwave energy heading north between greenland and scandi and in latest runs starting to show some sign of linking between hieghts in russia scandi if they keep upgrading once they link could the russian high be pulled over toward greenland and set up there.

if i am wrong on this i am sorry but i could swear i heard gp say that somewhere.

[Snowman.]

The Russian High getting shunted is the equivalent of hitting reset. We may not enjoy the refreshed outcome.

Have to say things are starting to look ominous for the next period (which is all that really matters). The two consistent things happening on the GFS runs at the moment are Azores ridging but not where we want it (mid Atlantic/Greenland) and a portion of the PV setting up home in Greenland after T240 or so.

Unless and until these two factors start trending differently we will not see cold before the first week of January IMO.

Considering how the PV is behaving wouldn't bet on it lasting their too long it's also fairly week with a predicted warming in 10hpa strat temperatures around Christmas. I wouldn't worry about the PV its days are numbered when it comes to setting up shop.

Edited December 12, 2012 by SN0WM4N

[nick sussex]

cheers nick thats what i was stuck on where it shows what direction.

well atleast thats a slight positive sign hopefully more will trend that way.

Yes if you look at the trend of the ECM operational run it at least takes some energy se'wards and thats what we want to see.

Because of the flat upstream pattern that really is the only real chance of some colder conditions.

I suspect the Xmas weather will be decided around 168hrs, thats where the GFS took the Azores high ridging ne, if that links up with ridging thrown sw from the Russian high then that would be time to hit the brandy!

Because the energy piles over the top and its a long haul back to cold.

So we want the Azores high as flat and as far away as possible. If we had more amplification upstream that could have helped, as it is we want it out of the picture.

If we get energy going se around that time whilst I can't promise anything sustained at least theres a better chance of some colder snaps.

[JP1972]

Some of the posts on here are frankly awful today and dare I say it painful to read.

[Frosty.]

The Russian High getting shunted is the equivalent of hitting reset.

It's been a flop, glad it's going to be honest, it just holds up the next pattern change so when it's gone we can get some fluidity back and maybe get some upstream amplification and mid atlantic ridge situation, the russian high in the position it's moving into is of no help to the uk's future cold prospects, good riddance to it!

Edited December 12, 2012 by Frosty039

[Rocheydub]

Considering how the PV is behaving wouldn't bet on it lasting their too long it's also fairly week with a predicted warming in 10hpa strat temperatures around Christmas. I wouldn't worry about the PV its days are numbered when it comes to setting up shop.

I've highlighted a very important word for you. This forecasted warming is as fallible as any weather forecasting, especially at that range.

[legritter]

Dont give up , there is a possibility of some interesting synoptics past 168 hrs ,just need to see some upgrades over next few days .we just need a LOW to shoot under us and it could be HUNT ON ,as for christmas looking at charts it could be a case of location for some .Chins up gang plenty of time left .but for now a real mess during friday then our friend zonal comes marching in .my little snow shower came up from lyme bay last night about 2 pixels on radar and lasted 5 mins ,but was special to see i switched on security lights ,as lamp post under austerity measures ,cheers legritter .

[Snowman.]

I've highlighted a very important word for you. This forecasted warming is as fallible as any weather forecasting, especially at that range.

Yes it all could go tits up but their is a real good signal with it being shown in every run for the past few days we're going to have to wait a good 3-4 days before it shows up on the ECM but it looking like a good trend.

[Summer Sun]

Here's the latest from Exeter curtsy of Ian Ferguson in the south west thread & Central Southern England

So, last cold night for the forseeable - -5 to -7 again quite plausible, but with much reduced fog signal, not least with breezier story developing into W Country, albeit some patchy freezing fog likely in Glos for a while.

Tomorrow fairly non-descript day of major pattern change transition - cloudier PM as it turns breezier still; the warm advection bringing patchy drizzle from the south into the evening along with increasing hill fog conditions.

Friday's heavy rain timing has good continuity in UKMO-GM and now NAE - very wet AM rush-hour; 5-15mm generally but thankfully passing eastwards fairly promptly albeit 4-6hrs rain quite possible. EA consider fluvial / pluvial flooding risk low generally, but caution also re a coastal low risk given wind/tide combination continuing into weekend. Heavy showers for W Country very much a feature into the weekend, with profiles bullish on CB potential; further heavy rain likely into early next week, too.

As you are probably aware (surely mentioned on one of the model threads?), to 10-15d prognosis from Exeter strongly signals a broad continuation of the same story from thereon to Christmas, with some periodic NE'rly influences affecting the N/NE UK at times as the PFJ steers some lows to the south of the UK. For our region (south west & Central Southern England), a continued threat of heavy rain / strong wind events. Meanwhile, the latest UKMO Seasonal picks-up where it was last issue (and in tune with EC Seasonal and that from NCEP) for a broadly zonal-dominated winter, albeit, of course, we put little stock in these highly experimental products for operational forecast matters or public messages.

[Buriedundersnow]

i'm not sure with this but maybe the more knowledgable or one of the mods can help me out here.

i'm sure i read i one of gp's post (i'm sure it was him anyway) that once the pv has moved to siberia it would encourage the russian scandi high to move toward greenland. plz can someone tell me if i am right there,

now with previous runs constantly showing less shortwave energy heading north between greenland and scandi and in latest runs starting to show some sign of linking between hieghts in russia scandi if they keep upgrading once they link could the russian high be pulled over toward greenland and set up there.

if i am wrong on this i am sorry but i could swear i heard gp say that somewhere.

could one of the mods plz tell me if gp had posted that about when the pv moves to siberia

[No Balls Like Snow Balls]

could one of the mods plz tell me if gp had posted that about when the pv moves to siberia

You could always read GP's old posts :-)

[Buriedundersnow]

You could always read GP's old posts :-)

how do u do that without having to troll through loads of different threads

[Paul]

You go into his profile and view his content:

http://forum.netweather.tv/user/2478-glacier-point/

But we're way off topic here, please can we keep it to the model output in this thread..