Model Output Discussion - 10th Jan Onwards

[johnholmes]

I've now commenced Indiana Jones and the Search for a cold Miracle! Perhaps I'm still in denial over this recent non cold debacle! Just a few things concerning the upstream pattern. There are some quite marked differences between the handling of shortwaves over in the USA between the models.

 

The ECM and GFS are pretty similar over the USA and the real divergence is between those and the UKMO as you can see here:

 

So the ECM at T96hrs:

 

ECH1-96.gif

 

Now the UKMO for the same time:

 

UN96-21.gif

 

This was the discussion by NCEP re the evolution before that timeframe:

 

...SECONDARY SYSTEM ARRIVING INTO THE GREAT LAKES BY 15/1200Z...

FINAL PREFERENCE: 00Z ECMWF

FORECAST CONFIDENCE: BELOW AVERAGE

ON THE WINGS OF THE INITIAL AMPLIFIED SHORTWAVE MARCHING THROUGH

THE TN VALLEY WILL BE ANOTHER SYSTEM EXPECTED TO REACH THE GREAT

LAKES BY EARLY WEDNESDAY. AS EXPECTED THIS FAR INTO THE SHORT

RANGE PERIOD...MODEL DIFFERENCES ARE EVIDENT WITH THE 00Z UKMET

BEING ONE OF THE SLOWER PIECES OF GUIDANCE OUT THERE. THE 00Z

ECMWF HAS SLOWED RELATIVE TO ITS PREVIOUS RUN WHILE ALSO NOT

DEPICTING THE CLOSED LOW CENTER IT HAD EARLIER ADVERTISED. GIVEN

THE IDEA OF FOLLOWING THE SLOWER SOLUTION FOR THIS LONGWAVE

TROF...WILL LEAN HEAVILY ON THE 00Z ECMWF HERE TO BE CONSISTENT

WITH THE FEATURE DOWNSTREAM. CHOOSE NOT TO INCORPORATE ITS

ENSEMBLE MEAN AS EXPECT THE NEW MEAN TO SLOW TO MATCH CLOSER TO

ITS OWN DETERMINISTIC MODEL.

What happens there will effect the troughing near the UK especially in terms of timing in relation to when these pieces of energy phase, as soon as they phase and depending on how they do so will effect  to a degree the movement of the troughing.Interestingly they haven't used the ECM ensemble mean because they think some of those ensembles are out of kilter with the upstream pattern.

 

Another thing from this mornings extended forecast discussion:

 

 THE MODELS/ENSEMBLES SHOW AN

AMPLIFIED CENTRAL PACIFIC RIDGE/POSSIBLE CLOSED HIGH...WHICH

USUALLY BLOCKS EAST FORWARD MOTION OF TROUGHS APPROACHING THE EAST

COAST.

 

And also this:

 

THE HIGH AMPLITUDE

RIDGE IN THE WEST WOULD FAVOR KEEPING AREAS OF LOW

PRESSURE FURTHER WEST...LIKE THE MEAN SOLUTIONS.

Now part of the problem across todays operationals is the flatness of the pattern especially in relation to the Azores high being unable to ridge sufficiently north to slow down the next upstream low, perhaps this is the new correct trend  which of course is certainly possible, if its not perhaps we may see some changes on tonights outputs.

 

Even with some changes though I think it's  a leap too far to expect anything majorly wintry to jump out, I think this is more in relation to how the troughing disrupts near the UK which may still develop a little wintry  interest.

 

As, if not even more important, is the upper air discussion they have, see below, and their discussions mirror pretty much what tthe anomaly charts suggested on 5-6 January for the time scale NOAA are discussing, so the major wave lengths are NOT expected to change.

EXTENDED FORECAST DISCUSSIONNWS WEATHER PREDICTION CENTER COLLEGE PARK MD1238 AM EST SUN JAN 12 2014VALID 12Z WED JAN 15 2014 - 12Z SUN JAN 19 2014...OVERVIEW AND PREFERENCES...THE MODELS/ENSEMBLES SHOW PERSISTENT CYCLONIC FLOW ACROSS THEBERING SEA.  TELECONNECTIONS OF THE PERSISTENT FEATURE LEAD TO AMEAN 500 MB RIDGE OVER THE NORTHWEST US AND SOUTHWEST CANADAAND DOWNSTREAM EASTERN US TROUGH.  MODELS AND ENSEMBLES SHOW GOODAGREEMENT WITH THE SUGGESTED TELECONNECTION PATTERN.  FROM DAY 3WED INTO DAY 5 FRI 17 JAN A BLEND OF THE 12Z ECMWF WITH THE 12ZECMWF MEAN WAS USED TO HANDLE THE WAVE DEVELOPMENT OVER THE MIDATLANTIC TO NORTHEAST.  FOR DAYS 5 FRI TO DAY 7 SUN A BLEND OF THE12Z ECMWF ENSEMBLE MEAN/12Z NAEFS ENSEMBLE MEAN/18Z GEFS MEAN WASUSED.  GOOD AGREEMENT EXISTED IN THE 500 MB WAVE PATTERN WITH ONLYMINOR TIMING/AMPLITUDE DIFFERENCES AMONG THE ECMWF ENSEMBLE MEANWITH THE 12-18Z NAEFS MEAN AND 18Z GEFS MEAN. THIS LENDS ITSELF TOA CONSENSUS APPROACH.

Edited January 12, 2014 by johnholmes

[nick sussex]

 

As, if not even more important, is the upper air discussion they have, see below, and their discussions mirror pretty much what tthe anomaly charts suggested on 5-6 January for the time scale NOAA are discussing, so the major wave lengths are NOT expected to change.

EXTENDED FORECAST DISCUSSIONNWS WEATHER PREDICTION CENTER COLLEGE PARK MD1238 AM EST SUN JAN 12 2014VALID 12Z WED JAN 15 2014 - 12Z SUN JAN 19 2014...OVERVIEW AND PREFERENCES...THE MODELS/ENSEMBLES SHOW PERSISTENT CYCLONIC FLOW ACROSS THEBERING SEA.  TELECONNECTIONS OF THE PERSISTENT FEATURE LEAD TO AMEAN 500 MB RIDGE OVER THE NORTHWEST US AND SOUTHWEST CANADAAND DOWNSTREAM EASTERN US TROUGH.  MODELS AND ENSEMBLES SHOW GOODAGREEMENT WITH THE SUGGESTED TELECONNECTION PATTERN.  FROM DAY 3WED INTO DAY 5 FRI 17 JAN A BLEND OF THE 12Z ECMWF WITH THE 12ZECMWF MEAN WAS USED TO HANDLE THE WAVE DEVELOPMENT OVER THE MIDATLANTIC TO NORTHEAST.  FOR DAYS 5 FRI TO DAY 7 SUN A BLEND OF THE12Z ECMWF ENSEMBLE MEAN/12Z NAEFS ENSEMBLE MEAN/18Z GEFS MEAN WASUSED.  GOOD AGREEMENT EXISTED IN THE 500 MB WAVE PATTERN WITH ONLYMINOR TIMING/AMPLITUDE DIFFERENCES AMONG THE ECMWF ENSEMBLE MEANWITH THE 12-18Z NAEFS MEAN AND 18Z GEFS MEAN. THIS LENDS ITSELF TOA CONSENSUS APPROACH.

Yes I saw that and agree but within that the detail on the ground for the UK may change, as you saw I was talking re the trough disruption and don't expect a deep easterly to just suddenly appear.

 

However if you use those ensemble means and operationals they're more amplified than whats on show today, the very point I was making was that the teleconnective correlation between those is not exactly what was dished up today by the outputs, so either todays outputs are correct and the pattern is going to be less amplified or they're a little too flat given the upstream ridge.

Edited January 12, 2014 by nick sussex

[fergieweather]

Sounds a bit suspect to me Nick. i know everyone's feeling cheesed off but i do think we need to wait until the end of today before we completely  dismiss the easterly.

The prospect of an easterly - albeit temporarily - from end of next weekend into following week can't be wholly discounted yet, albeit as of 00z output any support for such outcome sits at ca. 15% MOGREPS-15 and 10% EC. The key message from UKMO remains one of ongoing greater than average uncertainty beyond next weekend, with a wide range of possible synoptic outcomes. However, strongest signal ultimately is for some build of pressure to the south; northward bias to jet position and thus more unsettled to N/NW with rPm episodes introducing somewhat colder spells periodically. But the ongoing uncertainty remains a key message: this is something those who have "written-off" winter in a fit of pique might be advised to reflect on.

[karyo]

I really don't think there is any need for these comments you keep making regarding BFTP's posts. I have no idea if the moon affects the weather but I do know the incredible force it exerts on the Earth's oceans; perhaps it is not such a great leap of faith? There is after all, much left for science to completely understand. Anyway, people have different ideas and ways of interpreting the models, does that really necessitate the need to be rude?

I see nothing wrong with CC's post! BFTP and Roger were talking about a cold January (cold starting at the turn of the year) based on their forecasting method. Obviously, their forecast was wrong. Aren't we supposed to comment on that?

 

Karyo 

[lassie23]

We are stuck in this atlantic driven weather pattern for the whole month according to the models. Our only hope is that the block to our east doesn't vanish completely as it could push further west should the atlantic weaken come February, which can and has happen. We seem to be getting one mild winter and one cold  winter recently. Not the bad old days when it was 14c in Feburary and people were out without coats in the middle of winter. Whatnhas happened to the Stratospheric warming event, is it over?

[johnholmes]

Yes I saw that and agree but within that the detail on the ground for the UK may change, as you saw I was talking re the trough disruption and don't expect a deep easterly to just suddenly appear.

 

okay Nick, can you tell us just what detail on the charts linked below in the UK area you feel may happen as a result of what is happening in North America please. The basic idea on all the models is for low pressure to be sitting just west of the UK?

http://www.wetterzentrale.de/topkarten/fsavneur.html

with the latest Fax chart showing how Exeter see it, see below  again

http://www.weathercharts.org/ukmomslp.htm#t120

Or, are you talking about some time scale beyond that, and again, if I may ask, what is that?

cheers

[bluearmy]

Sounds a bit suspect to me Nick. i know everyone's feeling cheesed off but i do think we need to wait until the end of today before we completely dismiss the easterly.

This post is in response to nick's asking about the AO/NAO ECM ens progression, not John macs!

It is odd nick. They appear to be catching the gem/Canadian up re the stronger northern arm post days 8/10 but the sudden mean change to the shape of the Canadian vortex puzzles me a bit. It's as though a piece of crucial data has been missing at initialisation and now it's fed in - bingo. And in addition, we have the op and ens in agreement on this flatter upstream and yet NOAA have the op slower than the ens ??

methinks, it's worth waiting for the 12z's to see how this amplification upstream pans out on the next suite.

Edited January 12, 2014 by bluearmy

[john mac]

I've now commenced Indiana Jones and the Search for a cold Miracle! Perhaps I'm still in denial over this recent non cold debacle! Just a few things concerning the upstream pattern. There are some quite marked differences between the handling of shortwaves over in the USA between the models.

 

The ECM and GFS are pretty similar over the USA and the real divergence is between those and the UKMO as you can see here:

 

So the ECM at T96hrs:

 

ECH1-96.gif

 

Now the UKMO for the same time:

 

UN96-21.gif

 

This was the discussion by NCEP re the evolution before that timeframe:

 

...SECONDARY SYSTEM ARRIVING INTO THE GREAT LAKES BY 15/1200Z...

FINAL PREFERENCE: 00Z ECMWF

FORECAST CONFIDENCE: BELOW AVERAGE

ON THE WINGS OF THE INITIAL AMPLIFIED SHORTWAVE MARCHING THROUGH

THE TN VALLEY WILL BE ANOTHER SYSTEM EXPECTED TO REACH THE GREAT

LAKES BY EARLY WEDNESDAY. AS EXPECTED THIS FAR INTO THE SHORT

RANGE PERIOD...MODEL DIFFERENCES ARE EVIDENT WITH THE 00Z UKMET

BEING ONE OF THE SLOWER PIECES OF GUIDANCE OUT THERE. THE 00Z

ECMWF HAS SLOWED RELATIVE TO ITS PREVIOUS RUN WHILE ALSO NOT

DEPICTING THE CLOSED LOW CENTER IT HAD EARLIER ADVERTISED. GIVEN

THE IDEA OF FOLLOWING THE SLOWER SOLUTION FOR THIS LONGWAVE

TROF...WILL LEAN HEAVILY ON THE 00Z ECMWF HERE TO BE CONSISTENT

WITH THE FEATURE DOWNSTREAM. CHOOSE NOT TO INCORPORATE ITS

ENSEMBLE MEAN AS EXPECT THE NEW MEAN TO SLOW TO MATCH CLOSER TO

ITS OWN DETERMINISTIC MODEL.

What happens there will effect the troughing near the UK especially in terms of timing in relation to when these pieces of energy phase, as soon as they phase and depending on how they do so will effect  to a degree the movement of the troughing.Interestingly they haven't used the ECM ensemble mean because they think some of those ensembles are out of kilter with the upstream pattern.

 

Another thing from this mornings extended forecast discussion:

 

 THE MODELS/ENSEMBLES SHOW AN

AMPLIFIED CENTRAL PACIFIC RIDGE/POSSIBLE CLOSED HIGH...WHICH

USUALLY BLOCKS EAST FORWARD MOTION OF TROUGHS APPROACHING THE EAST

COAST.

 

And also this:

 

THE HIGH AMPLITUDE

RIDGE IN THE WEST WOULD FAVOR KEEPING AREAS OF LOW

PRESSURE FURTHER WEST...LIKE THE MEAN SOLUTIONS.

Now part of the problem across todays operationals is the flatness of the pattern especially in relation to the Azores high being unable to ridge sufficiently north to slow down the next upstream low, perhaps this is the new correct trend  which of course is certainly possible, if its not perhaps we may see some changes on tonights outputs.

 

Even with some changes though I think it's  a leap too far to expect anything majorly wintry to jump out, I think this is more in relation to how the troughing disrupts near the UK which may still develop a little wintry  interest.

Amazing, we can find some possible straws to clutch when we put our mind to it!! lol . Nice one nick.

[nick sussex]

The prospect of an easterly - albeit temporarily - from end of next weekend into following week can't be wholly discounted yet, albeit as of 00z output any support for such outcome sits at ca. 15% MOGREPS-15 and 10% EC. The key message from UKMO remains one of ongoing greater than average uncertainty beyond next weekend, with a wide range of possible synoptic outcomes. However, strongest signal ultimately is for some build of pressure to the south; northward bias to jet position and thus more unsettled to N/NW with rPm episodes introducing somewhat colder spells periodically. But the ongoing uncertainty remains a key message: this is something those who have "written-off" winter in a fit of pique might be advised to reflect on.

Thanks for your update Ian, as for the easterly as you know I'm a coldie but have moved on from that, any deep cold is likely to remain stuck to the east, I think the uncertainty perhaps more with how the trough disruption occurs near the UK, some previous outputs showed that splitting and a briefish faux easterly as I like to call it as it won't be pulling in deep cold but may still be cold enough to develop some wintriness.

 

I think the uncertainty given the outputs is whether energy continues to slip se through the UK  or whether the pattern moves towards the Azores high ridging ne more quickly.

 

Of course I don't have access to the MOGREPS but looking at the trends that would seem the likeliest point of conjecture especially if those NOAA anomaly maps are correct.

[john mac]

This post is in response to nick's asking about the AO/NAO ECM ens progression, not John macs!It is odd nick. They appear to be catching the gem/Canadian up re the stronger northern arm post days 8/10 but the sudden mean change to the shape of the Canadian vortex puzzles me a bit. It's as though a piece of crucial data has been missing at initialisation and now it's fed in - bingo. And in addition, we have the op and ens in agreement on this flatter upstream and yet NOAA have the op slower than the ens ??methinks, it's worth waiting for the 12z's to see how this amplification upstream pans out on the next suite.

Agreed, It's so frustrating on here sometimes when people just write off certain senario's because they take every run that comes out at face value. As Ian F has said there is a great amount of uncertainty at the moment in the medium time frame and the are still several possible outcomes, so i think should hold our horses for a bit longer yet! lol

[nick sussex]

okay Nick, can you tell us just what detail on the charts linked below in the UK area you feel may happen as a result of what is happening in North America please. The basic idea on all the models is for low pressure to be sitting just west of the UK?

http://www.wetterzentrale.de/topkarten/fsavneur.html

with the latest Fax chart showing how Exeter see it, see below  again

http://www.weathercharts.org/ukmomslp.htm#t120

Or, are you talking about some time scale beyond that, and again, if I may ask, what is that?

cheers

 I think my reply to Ian should suffice, however what happens re the track of low pressure over the eastern USA will effect the Azores high.

[Long haul to mild]

But the ongoing uncertainty remains a key message: this is something those who have "written-off" winter in a fit of pique might be advised to reflect on.

Wise words there; but will it stop the usual suspects throwing their toys every time there's not a screaming Easterly shown in the runs? Sadly, I doubt it somehow.Nothing is decided beyond a few days at present, yet alone the rest of January. As for writing off winter on the 12th January, that's just laughable. February has historically been a very good month for snow in the UK.

[johnholmes]

Nick, I detect a touch of techiness in your reply but I am asking genuine questions because I am simply not quite sure of just what you mean. If the upper flow remains much as before, the anomaly charts suggest this and NOAA comments seem to agree with what they show, just what effect can the surface low have on the UK and when is what I am trying to find out from you.

I have no problem with us disagreeing but it would help the discussion if you could answer my question - please?

 

I have taken a very close look at the anomaly charts NOAA issued last night covering the 6-14 day periods and it is open to discussion just what is going to happen to the upper air pattern just SW of the Uk and into western Europe. I copy the link for you and others to be able to see and I am more than happy to discuss what you/I or others feel they show and what may develop from them. That is assuming they are close to the mark anyway. Who knows when we see the upper air by t00 on day 14 they may be quite wrong?

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

[john mac]

Wise words there; but will it stop the usual suspects throwing their toys every time there's not a screaming Easterly shown in the runs? Sadly, I doubt it somehow.Nothing is decided beyond a few days at present, yet alone the rest of January. As for writing off winter on the 12th January, that's just laughable. February has historically been a very good month for snow in the UK.

We Shall see, But there's one thing for sure. The 12z runs will be different to the 00z runs.

[Iceni]

Hideous Jet Stream pattern over the next couple of weeks… look at 180hrs to the lo-res…

 

 

That's it! I've had enough! We're moving to Canada.

Edited January 12, 2014 by Iceni

[Summer Sun]

Latest NAO update shows it heading positive from around the 16th before dropping back down towards neutral

 

 

Latest AO update shows it going back to negative after a short time before it looks like going positive again albeit with a lot of scatter

 

[Ali1977]

Still plenty of winter left, if charts not even in our FI radar (+384) start showing cold in the next week we could still have a 2 month deep freeze, that's how much winter we have left.

Not throwing the towel in yet.

Optimist !!!!!

Edited January 12, 2014 by Ali1977

[john mac]

Agreed, It's so frustrating on here sometimes when people just write off certain senario's because they take every run that comes out at face value. As Ian F has said there is a great amount of uncertainty at the moment in the medium time frame and the are still several possible outcomes, so i think should hold our horses for a bit longer yet! lol

I'd be surprised if that chart verified. As i said earlier there's a wide range of variables from the end of the week onwards.

[JOPRO]

Hideous Jet Stream pattern over the next couple of weeks… look at 180hrs to the lo-res…

That's it! I've had enough! We're moving to Canada.

Will be different again on the next run no doubt. Edited January 12, 2014 by JOPRO

[john mac]

Still plenty of winter left, if charts not even in our FI radar (+384) start showing cold in the next week we could still have a 2 month deep freeze, that's how much winter we have left.Not throwing the towel in yet.Optimist !!!!!

You'd be mad to mate lol, although the easterly hasn't materialized there will be plenty more chances down the line. Often cold set ups have popped up at quite short notice in the past so all to play for.

Anyway the GEM will be out soon for the round of fun and games!

Edited January 12, 2014 by john mac

[Iceni]

Still plenty of winter left, if charts not even in our FI radar (+384) start showing cold in the next week we could still have a 2 month deep freeze, that's how much winter we have left.Not throwing the towel in yet.Optimist !!!!!

 

But I don't want two months of deep freeze in March or April or even February. It's when I want to be outside  getting the garden up and running for summer (ever tried weeding or planting in 6 inches of soaking wet or frozen clay?). It's when our orchard blossom comes out, but there is nothing around to pollinate it and therefore no crop like 2012.

 

I suppose a few weeks relief from the constant mud and dirt that's carried into the house as a result would be nice - but that's all.

 

 

Will be different again on the next run no doubt.

 

 

t180 to lo res was only the height of the horror, the previous output is just as ghastly…

 

Face it the Atlantic and the jet stream are in charge for the foreseeable. There's not a chance of any heights building over Greenland or Scandi in time to rescue January 2014.

Edited January 12, 2014 by Iceni

[stewfox]

We are stuck in this atlantic driven weather pattern for the whole month according to the models. Our only hope is that the block to our east doesn't vanish completely as it could push further west should the atlantic weaken come February, which can and has happen. We seem to be getting one mild winter and one cold  winter recently. Not the bad old days when it was 14c in Feburary and people were out without coats in the middle of winter. Whatnhas happened to the Stratospheric warming event, is it over?

 

 

Lassie I was like you once, then I actually read what the season forecaster were saying , 'uncertainty' is the key don't put the coat in the attic just yet, hell you may even need it for March 

 

Strat details found here well worth a read

 

http://forum.netweather.tv/topic/78161-stratosphere-temperature-watch-20132014/

 

The prospect of an easterly - albeit temporarily - from end of next weekend into following week can't be wholly discounted yet, albeit as of 00z output any support for such outcome sits at ca. 15% MOGREPS-15 and 10% EC. The key message from UKMO remains one of ongoing greater than average uncertainty beyond next weekend, with a wide range of possible synoptic outcomes. However, strongest signal ultimately is for some build of pressure to the south; northward bias to jet position and thus more unsettled to N/NW with rPm episodes introducing somewhat colder spells periodically. But the ongoing uncertainty remains a key message: this is something those who have "written-off" winter in a fit of pique might be advised to reflect on.

Edited January 12, 2014 by stewfox

[BLAST FROM THE PAST]

Don't tell me the moon has changed its mind again.

 

Back to the models and meteorological way of looking at the weather.

You obviously didn't use meteorological way on you December forecast, more the 'madden way'

Hats tipped to the rest of the post… Anyway interesting stuff

BFTP

[john mac]

But I don't want two months of deep freeze in March or April or even February. It's when I want to be out getting the garden up and running for summer, when orchard blossom comes out but there is nothing around to pollinate it.

 

I suppose a few weeks relief from the constant mud and dirt that's carried into the house as a result would be nice - but that's all.

 

 

 

 

t180 to lo res was only the height of the horror, the previous output is just as ghastly…

 

Face it the Atlantic and the jet stream are in charge for the foreseeable. There's not a chance of any heights building over Greenland or Scandi in time to rescue January 2014.

It might be worth reading ian f's earlier posts re the high uncertainty beyond this week let alone the rest of the month.

[Long haul to mild]

I can officially announce that the hunt for cold is over! Yes, I have just been outside for a few minutes and I can confirm that it is.....cold

Joking aside, I'm expecting to see better 12z runs. It's probably once of those myths, but I can't remember the last time I got up in the morning and looked at the forums to see people celebrating over the 00z models. Just seems to me that the models save all the good stuff for the afternoon runs!

Edited January 12, 2014 by Chalk Serpent