Model Output Discussion 29th December - Into mid-Winter.

[Ali1977]

A slack Easterly looks pretty odds on, not a (beasterly) easterly but still very cold.  I think early next week we could easily see -10c minimums or colder even down South, potentially colder in the centre of the high.  If the high does stay slightly more south, which may not prolong the cold it may actually give us colder nights for a few days. Potential Ice days and severe frosts are a rare thing over the last few years.

Edited January 10, 2017 by Ali1977

[ArHu3]

5 hours ago, karlos1983 said:

I would say nailed on if the uppers are ok

Are these surprise events? Ecmwf show no or very little snow

[Seasonality]

1 minute ago, Nick F said:

All this talk of easterlies this morning and it's the 30th anniversary in a few days of the start of the infamous January 1987 beasterly, the Holy Grail of easterlies. The 13th of Jan '87 saw sub -15C T850s spread from the east. Only seems like yesterday I was helping to dig through a snow drift in Kent, aged 11, with my father so we could get our back home. How time flies!

Anyway, enough reminiscing, looking at the 06z GEFS postage stamps, main concern re: easterly potential is that quite a number of members not really building  the high far enough north and northeast so we don't get a decent a cold easterly flow, with only a few members with a strong and cold easterly flow, but at least the Atlantic looks blocked and will be cold under high pressure inversion. Still chance of cold easterly - despite this IMO.

You can see the cold air directly drawn from the Russian arctic. It was a particularly savage spell for Central Europe too as you can see from the 850 chart with the deepest cold sat over Poland and what was at that time Czechoslovakia. Temperatures in Warsaw went below -30 degrees C, record cold although Polish weather records don't go as far back as in the UK. Even colder in the countryside and colder parts with altitude and geography as of course readings in a city are subject to UHI. The Baltic Sea froze over almost in its entirety that winter with an ice sheet extending down to the Polish coast. Dreadful stuff.

[samadamsuk]

Morning all,

A very fabourable GFS run compared to yesterday imo - the north diving arm of the js through europe completely detatches at about t204, then gets absorbed opening the floodgates from the east. All a bit worryingly far away, even with cross model support at this stage, but lining up on the large scale at the moment.

If nothing transpires - enjoy the journey!, even if the destination is a let down - hope is fun!

Samos

[Summer Sun]

GFS 06z Op is on the cold side of the mean from the 16th to 22nd-ish

 

[Iceaxecrampon]

Well well.

The last few pages have made good reading of the search for the  "Holy Grail" easterly....

Cumbria Ensemble temps taking a nosedive for the same timescale.

Interesting.

Can't wait 

[samadamsuk]

Hi All,

 

Not sure if these images show up ok? - here's the point where the Jetstream realigns

[jvenge]

The Op was on the colder side of the 06z and looking at the ensembles, one could see scenarios where the UK is watching a cold continent while being in near normal temperatures or slightly below. Attached the ensemble mean to show this.

From the 12z, those of a colder persuasion will be wanting to see some more westward correction.

[memories of 63]

4 minutes ago, Summer Sun said:

GFS 06z Op is on the cold side of the mean from the 16th to 22nd-ish

 

But on the warmer side earlier than that

[Summer Sun]

Just now, memories of 63 said:

But on the warmer side earlier than that

Only for 1 day Sunday into Monday then again from the 22nd to 23rd/24th

[Tim Bland]

Metoffice still not buying into the Easterly.  with long range text forecast (just updated) going for the Atlantic return on Sunday.  Really bizarre, cant understand why they are still not buying it?

[matty40s]

On Thursday, December 29, 2016 at 13:41, tinybill said:

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

well  going  by  the  gfs  things  might  start  get interesting  after jan  6  for the coldies

Jan 6th 2018??

[nick sussex]

We need a new global model that comes out about now! This time of the day has us in a holding pattern waiting for the evening runs, most of the excitement or drama has happened so we're now left to ponder what will actually verify come the day.

It would take a really dramatic twist to not deliver something from the east but the issue for the UK and which is often the hardest hurdle to overcome is getting high pressure sufficiently north to advect the coldest air westwards and then get an easterly that can deliver convection off the North Sea rather than that grey cloudy easterly with snow grains.

Many of us really only remember the ones that came with snow showers and they've been a rarity in recent years, we've seen a lot of mention of January 1987 and that one does stick in the memory. I remember walking around the Serpentine in London and just marvelling at how beautiful everything looked.

I'm not sure whether that's really attainable in the current set up, the most potent easterlies normally include a lobe of the PV dropping south to the east and that cold air being pulled westwards. We're not seeing that modelled at present.

There is though still the possibility of at least some snow showers depending on the development of low pressure over southern Europe which could help strengthen the flow.

Theres still a lot to be resolved especially as the UKMO still isn't really as good as the ECM and the GFS wants to model a different evolution with the trigger shortwave.

[london-snow]

3 minutes ago, jvenge said:

The Op was on the colder side of the 06z and looking at the ensembles, one could see scenarios where the UK is watching a cold continent while being in near normal temperatures or slightly below. Attached the ensemble mean to show this.

From the 12z, those of a colder persuasion will be wanting to see some more westward correction.

It's been like this for a while ' Close but no cigar ' type of set up. Plenty of interest now turns towards the mid month stand off as to whether or not we see and join the fun and games or we pull out our telescopes and look east from the window with you're right hand clenched in a fist of fury.

 

Time will tell...

[Man With Beard]

ECM ensembles London

Whilst the ECM op was within the main cluster for D6-9, it looks like it is losing touch by D10. Really not wise to start thinking about a "locked-in" easterly just yet. But good support for a fairly decent cold(ish) spell lasting up to a week.

[chrisbell-nottheweatherman]

4 minutes ago, Man With Beard said:

ECM ensembles London

Whilst the ECM op was within the main cluster for D6-9, it looks like it is losing touch by D10. Really not wise to start thinking about a "locked-in" easterly just yet. But good support for a fairly decent cold(ish) spell lasting up to a week.

That being said (and there's plenty of uncertainty earlier) there's no real sign of a mild cluster into FI, merely a scatter of perturbations.  Both clusters at that point are between -5C and +5C.

Edited January 10, 2017 by chrisbell-nottheweatherman
Correcting typo.

[Gustywind]

8 minutes ago, Tim Bland said:

Metoffice still not buying into the Easterly.  with long range text forecast (just updated) going for the Atlantic return on Sunday.  Really bizarre, cant understand why they are still not buying it?

Probably because their model doesn't show an easterly. The t144 looks to have a bit too much energy in the northern arm so would probably show a mid latitude high, followed eventually by the Atlantic returning. Personally given this is an evolving situation I wouldn't be too concerned at this stage by their forecast.

[PersianPaladin]

10 minutes ago, Bazray said:

Met office weather warning map showing somewhat of a downgrade.

looks like only the far west will see snow and the South has been removed from the Amber warning

Is that for Thursday? Too far out for such mesoscale detail. Ignore it.

It will literally come down to nowcasting with regard to how that unstable trough descends southward.

Edited January 10, 2017 by PersianPaladin

[bradymk]

12 minutes ago, Tim Bland said:

Metoffice still not buying into the Easterly.  with long range text forecast (just updated) going for the Atlantic return on Sunday.  Really bizarre, cant understand why they are still not buying it?

Too much uncertainty still I imagine. Although if we're in the same position this time tomorrow with GEFS on board too, I imagine we'll see a v different wording. Only other thing is if MOGREPS isn't seeing it either. 

Easterly aside, latest metoffice warnings showing the uncertainty for Thursday with the northern extent of that low pressure! Be coming into euro4 more later.

 

 

[Polar Maritime]

Posts removed as off topic, Please use the correct thread for METO extended outlooks.

Thanks, Please continue with discussion on what the Model Outputs are showing.

[nick sussex]

I would be surprised if the UKMO don't include some mention of an easterly or at least some colder air coming in from the east/se. Their own model shows this at T168hrs and they do factor in the ECM and its ensembles.

 

Edited January 10, 2017 by nick sussex

[Geordiesnow]

I think the easterly signal is increasing but I would still hedge on the bet that high pressure will probably be the dominant factor however it helps to prolong the cold spell that is for sure.

There is a little convective potential showing on the GFS/ECM even if albeit its probably quite brief however sometimes easterlies can be a bit of a slow burner when it comes to actual convection. Either way, the forecast could well be edgeing away from turning milder and wetter from the west to something more drier with the risk of severe frosts away from north-western parts.

[Nouska]

52 minutes ago, Nick F said:

All this talk of easterlies this morning and it's the 30th anniversary in a few days of the start of the infamous January 1987 beasterly, the Holy Grail of easterlies. The 13th of Jan '87 saw sub -15C T850s spread from the east. Only seems like yesterday I was helping to dig through a snow drift in Kent, aged 11, with my father so we could get our car back home.

My word, I can see why you needed to do so much digging. Some of those historic events now have a little more detail and time stamps from the ECM ERA charts available on Meteociel.

Jan '87 ppn/snowfall ...

http://www.meteociel.fr/modeles/archives/archives.php?day=1&month=1&hour=0&year=1987&map=7&region=uk&mode=2&type=era

 

[Catacol]

1 hour ago, Tim Bland said:

Metoffice still not buying into the Easterly.  with long range text forecast (just updated) going for the Atlantic return on Sunday.  Really bizarre, cant understand why they are still not buying it?

Because it is never the safe call. The percentage route is to assume easterlies in winter are hard to come by.... and there isn't enough evidence yet. Remember that the minute a mid January easterly is called then it has implications for councils and business and industry because the fall in temperatures and potential for disruptive snow (though not ALL easterlies bring snow as we have seen before) will cause problems. They will want to be over 90% certain I would suggest before sounding the bell and instructing their link organisations to prepare.

If it comes off then GP is going to be smiling. All the ups and downs of the last week, and his prediction just prior to New Year may come to fruition despite the dodgy signals. The gradual awakening of the MJO flagged a couple of days ago looks significant. The BOMM (not updated since 5th Jan) was all for growing amplification, and the other resident pacific model - the JMA - also seeing it

This kind of higher orbit may be all that is needed to tip the block to the desired latitude. I thought this week might produce some fascinating model watching.... its not disappointing so far!

[Seasonality]

1 hour ago, jvenge said:

The Op was on the colder side of the 06z and looking at the ensembles, one could see scenarios where the UK is watching a cold continent while being in near normal temperatures or slightly below. Attached the ensemble mean to show this.

From the 12z, those of a colder persuasion will be wanting to see some more westward correction.

All looks a bit underwhelming when laid out in terms of the t2m anomaly progression. What is interesting is that for a brief window the UK has a negative anomaly whereas much of Europe has a positive anomaly (actual temperatures still colder than UK in some cases, these are anomalies after all and the UK average temp is rather mild). It illustrates the soon to arrive northerly influence very well. For most of the run the colder anomalies remain over Europe so I agree that westward progression is the way for cold fans if they want to go from good to great. However, on the bright side for cold fans, ECM looks like it would be colder at the surface. Furthermore, it has handled the surface temperatures much better than the GFS in the European cold spell with ECM being more accurate (and much colder). This is something @jvenge and I have discussed in some detail and has held true for locations as far apart as Warsaw and Chisinau. I don't have the expertise to speculate on whether this would hold true for the UK in a potential easterly regime but it may help bring further cheer to coldies.