Model Output Discussions 12z 01/09/2016

[Seasonality]

39 minutes ago, weirpig said:

I really like those  charts. Were they posted a few days ago off a Hungarian site?   You can quite clearly see the trend over the next 10 days or so  for a north easterly to set in   and also how warm central,Eastern  Europe becomes  i think for the forseable we need to look north for our weather.

Central Europe doesn't become warm. The EC update shows temperatures below average for the first two weeks of November and then no clear signal thereafter. Have posted a map of central Europe as I find many people confuse it with eastern Europe and south east Europe.

 

 

 

Edited November 1, 2016 by Seasonality

[weirpig]

1 minute ago, Seasonality said:

Central Europe doesn't become warm. The EC update shows temperatures below average for the first two weeks of November and then no clear signal thereafter. Have posted a map of central Europe as I find may people confuse it with eastern Europe and south east Europe.

 

 

 

Sorry  Season, Yes more eastern Europe perhaps getting warmer 

[Ravelin]

Everything in our vicinity slightly further West on the GFS 6Z by t156 (Monday 19:00)

0Z   6Z

Not making a huge difference to the 850 temps though.

[Summer Sun]

Big upgrade on the snow row for Inverness the 12z yesterday peaked at 10 the 00z takes it up to 17 on the 5th / 6th

[Ali1977]

Not many comments on the 06z, as expected as not much to get exited about for coldies.  Just had a look at the 10hPa strat in FI though, should that be centred in Scotland? Every run seems to move it slightly further SW from the Pole, and it gets slightly less cold.  

I feel a sudden swing in mid Month to proper Winter cold is still a decent possibility, especially after reading the various "unusual" things going on with the votex etc...

[Summer Sun]

Not a great deal of change on the 00z ECM ens with a northwesterly flow setting up for most of next week

[weirpig]

The most startling  aspect of that run for me is the warmth thats being experienced in North America  and Canada.  Will that have implications going forward?

[Gael_Force]

3 minutes ago, Ali1977 said:

Not many comments on the 06z, as expected as not much to get exited about for coldies.  Just had a look at the 10hPa strat in FI though, should that be centred in Scotland? Every run seems to move it slightly further SW from the Pole, and it gets slightly less cold.  

I feel a sudden swing in mid Month to proper Winter cold is still a decent possibility, especially after reading the various "unusual" things going on with the votex etc...

I don't know about this time of year but it was over Scotland at one point early in the year and is what led to all those beautiful pearlescent cloud formations.

[feb1991blizzard]

Here she comes anyway.

[Ali1977]

6 minutes ago, feb1991blizzard said:

Here she comes anyway.

Start of an SSW maybe?  That would be great this early on, a cold Dec and a destroyed PV for the rest of the year.  No doubt it'll vanish on the 12z.

[Zakos]

We are starting to see signs of the PV trying to form over Greenland from the models.

The models are also showing the Atlantic firing up... which is to be expected at this time of year.

However, we are not yet seeing signs of a true return to Atlantic conditions.

ECM and GFS at day 10. 

we are seeing sings of low heights developing over Greenland.

However, both ECM and GFS have a very blocked Atlantic, and both keep low heights over central Europe.

No sign of a return to south westerlies, however yes we are seeing signs of Atlantic activity.

The UK is often the last area to receive the cold from these setups.

Looking at this as a European cold spell, both models maintain the cold in Europe right up to day 10. Aslong as cold air is situated so close to the UK, there is always potential for small changes in the output, producing cold conditions for the UK.

I suspect the models are underestimating the strength of the blocking in the Atlantic, time will tell.

Very wide spread from the NAO forecast today. I am unsure what model(s) are used for this forecast, however the runs are in clear agreement of the NAO diving negative. Beyond a few days, the models  appear to have no clue

 

Edited November 1, 2016 by Zakos

[feb1991blizzard]

Just now, Ali1977 said:

Start of an SSW maybe?  That would be great this early on, a cold Dec and a destroyed PV for the rest of the year.  No doubt it'll vanish on the 12z.

Probably one for the strat thread this but I don't think it will be a full on SSW but we wont need one this early, not sure if it would actually class as an SSW if it did happen as they are usually also referred to as Midwinter warmings where as this would be in late autumn if it happened, I suppose it would class as one as the zonal winds are slightly +ve at 10mb, 60N now so I suppose a reversal would qualify, not sure whether it will just be a displacement or whether a split will actually occur,  either way, at least its not a great big strong vortex centered slap bang over the pole.

 

PS - I think that Strat event that caused the sky to go a funny colour was 2010, that's what I remember being talked about anyway, I read something in the Telegraph about it.

[Barry12]

You know we are in a good position when one individual GFS run in FI has the Atlantic influencing our weather for a short period of time, is the worst thing we've seen in weeks. In the reliable timeframe we have cold air incoming from the East bringing temperature below average for the whole of the UK. We have a massively negative AO, GLOSEA and the EC46 are forecasting mostly N/NW winds for the UK for most of November. We are in a great position, theirs no need to be negative.

[Summer Sun]

In the short term a drop in temperatures looks nailed on now

Longer term the GFS 06z goes for an alternating pattern of milder air and cooler air from the 9th

[snowy weather]

9 minutes ago, feb1991blizzard said:

Probably one for the strat thread this but I don't think it will be a full on SSW but we wont need one this early, not sure if it would actually class as an SSW if it did happen as they are usually also referred to as Midwinter warmings where as this would be in late autumn if it happened, I suppose it would class as one as the zonal winds are slightly +ve at 10mb, 60N now so I suppose a reversal would qualify, not sure whether it will just be a displacement or whether a split will actually occur,  either way, at least its not a great big strong vortex centered slap bang over the pole.

 

PS - I think that Strat event that caused the sky to go a funny colour was 2010, that's what I remember being talked about anyway, I read something in the Telegraph about it.

This sounds very interesting, have you got any information on this?

[feb1991blizzard]

1 minute ago, snowy weather said:

This sounds very interesting, have you got any information on this?

No, i just remember vaguely, I'm sure it was late 2010 and the article was in the telegraph around mid January 2011 talking about the stratosphere, there might be a link to it in the MOD thread around 2011 but good luck if you can find it!

[weirpig]

Rince and repeat on the control

 

[Gael_Force]

28 minutes ago, feb1991blizzard said:

PS - I think that Strat event that caused the sky to go a funny colour was 2010, that's what I remember being talked about anyway, I read something in the Telegraph about it.

No, it was early February this year. Had to go look in the images section to get dates. There might have been something similar in 2010 but I don't remember that one.

Edited November 1, 2016 by Gael_Force

[weirpig]

Having a quick look at the Ensembles  there is quite a few that are going for height rises again towards greenland  after this initial cool snap.  infact most have attempted rises somewhere  in the later output.  including the control.

Edited November 1, 2016 by weirpig

[weirpig]

http://www.metoffice.gov.uk/services/public-sector/contingency-planners

Sorry had to sit on this until formally released in last few minutes!

 

Hope fergie does not mind me posting  this in here   what a update!

[Ali1977]

7 minutes ago, weirpig said:

http://www.metoffice.gov.uk/services/public-sector/contingency-planners

Sorry had to sit on this until formally released in last few minutes!

 

Hope fergie does not mind me posting  this in here   what a update!

Am I correct in saying this goes with a colder Dec/Jan than Normal - rather than Nov. 

[weirpig]

1 minute ago, Ali1977 said:

Am I correct in saying this goes with a colder Dec/Jan than Normal - rather than Nov. 

I believe its the mean of the three months.  30 % chance of it being in the coldest sector 

[Nouska]

33 minutes ago, feb1991blizzard said:

No, i just remember vaguely, I'm sure it was late 2010 and the article was in the telegraph around mid January 2011 talking about the stratosphere, there might be a link to it in the MOD thread around 2011 but good luck if you can find it!

The nacreous clouds were over the UK due to the unusual positioning of the stratospheric vortex - you need colder than -80C overhead for formation.

http://www.metoffice.gov.uk/learning/learn-about-the-weather/clouds/nacreous

To what is being modelled in the here and now.

No SSW but the potential for a Canadian style displacement where there is a possibility of early reversal.

The cold is not present at the beginning of winter but think of what followed - a high pressure, easterly spring in the north of the UK and a cold and wet one further south - including here.

Transpose the scenario to the start of winter and we might be in business to see something very different, to recent winters, down the line.

[fergieweather]

22 minutes ago, Ali1977 said:

Am I correct in saying this goes with a colder Dec/Jan than Normal - rather than Nov. 

Correct. GloSea5 points to a weakened PV throughout the period. Note the markedly low probability for +ve avg temperatures overall (compare to last year's prognosis!). Anyway, it's all for a different thread: Apols mods. :-)

[weirpig]

9 minutes ago, fergieweather said:

Correct. GloSea5 points to a weakened PV throughout the period. Note the markedly low probability for +ve avg temperatures overall (compare to last year's prognosis!). Anyway, it's all for a different thread: Apols mods. :-)

Again maybe off topic  but it mentions  30% chance of being in the coldest sector (5)   is there a list/diagram of these sectors  which will correlate to what they represent in temps