Model Output Discussion

[SP1986]

The winter here has been very good and for you in the UK, I was merely making the point that theres very few chances in the UK to get some very cold upper air so it would be nice to see this happen, the likely cold pooling to the east doesn't happen often so thats really what I was alluding to.

Sorry Nick I totally forgot you'd moved to France, I had assumed you were in the UK

[Guest North Sea Snow Convection]

The data was there a week ago, MMW, MJO,convection building over the date line, ridging into the Arctic,

hights moving across the pole and linking with the Siberian high, GLAAM and mountain torques predicted to

rise which you could see on the northern hemisphere charts,hints of fast downward propagation of easterly

winds in the stratosphere together with the warming and also remembering the initial response last year to a

sudden stratosphere warming (MMW)plus looking at the developing circulation pattern in the northern

hemisphere which I kept asking people to look at.

I don't know, but it seems maybe you are trying to put forward a case for being the best forecaster around that there is

Let me put it this way, the data was there, but the ingredients were not yet as primed or able to potentially deliver (imo) to the same degree as they might now. It doesn't change the point that I am making that there was, and to quite a degree still is, no certainty that these factors would or will deliver a UK cold spell.

People such as me as well as other regulars on here always look at the northern hemisphere circulation pattern as a matter of course. But doing that doesn't guarantee a cast iron outcome like you seem to think it does - otherwise we would all be millionaire forecasters! lol!

However, based on looking at those, personal interpretations about the outlook are made. Just as one example, as chionomaniac documents on the stratosphere thread, no MMW is the same, nor has the same effects in the same places every time. Somethimes they have no effects at all. In fact none of the above factors you mention above, even in combination, guarantee a cold spell for the UK - even if the chances are of course enhanced. Just because they may potentially interact favourably doesn't automatically mean a big UK freeze

So unlike you, I personally was not nearly as assured about an imminent cold spell as you were./are. I would like to think that in the event, that decision has been reasonably well validated so far on the basis that the models have been over progressive with the evolution to the next (possible) cold spell. Not that it matters especially if it does or has been validated, as this is just for fun, and not a 'competition to win' as far as I am concerned.

Still, I have come a cropper like others before though in terms of letting hopes override realities and hence if I have learned anything at all from net weather and the valuable information and expert opinions available on here it is my decision these days to take a more measured and objective view instead of what I could still do and predict cold just because I want it to be cold.

[Bobby]

Looking a better run so far the 12z. Things are more south and west meaning the cold stays over us better.

Edited January 28, 2010 by Barb-

[cooling climate]

I don't know, but it seems maybe you are trying to put forward a case for being the best forecaster around that there is

Let me put it this way, the data was there, but the ingredients were not yet as primed or able to potentially deliver (imo) to the same degree as they might now. It doesn't change the point that I am making that there was, and to quite a degree still is, no certainty that these factors would or will deliver a UK cold spell.

People such as me as well as other regulars on here always look at the northern hemisphere circulation pattern as a matter of course. But doing that doesn't guarantee a cast iron outcome like you seem to think it does - otherwise we would all be millionaire forecasters! lol!

However, based on looking at those, personal interpretations about the outlook are made. Just as one example, as chionomaniac documents on the stratosphere thread, no MMW is the same, nor has the same effects in the same places every time. Somethimes they have no effects at all. In fact none of the above factors you mention above, even in combination, guarantee a cold spell for the UK - even if the chances are of course enhanced. Just because they may potentially interact favourably doesn't automatically mean a big UK freeze

So unlike you, I personally was not nearly as assured about an imminent cold spell as you were./are. I would like to think that in the event, that decision has been reasonably well validated so far on the basis that the models have been over progressive with the evolution to the next (possible) cold spell. Not that it matters especially if it does or has been validated, as this is just for fun, and not a 'competition to win' as far as I am concerned.

Still, I have come a cropper like others before though in terms of letting hopes override realities and hence if I have learned anything at all from net weather and the valuable information and expert opinions available on here it is my decision these days to take a more measured and objective view instead of what I could still do and predict cold just because I want it to be cold.

I certainly would not pretend to even think I was the best forcaster around here, not even close

and the lecture was not necessary by the way. why you feel the need to keep responding to my

posts I don't know.

Its time to put a line under this.

[Thundery wintry showers]

I expect some kind of snowy easterly out in "Fantasy Island" on the GFS run this time- indeed, everything is further south and the Atlantic lows are held well out to the west. But before cold/snow lovers can get too excited we need the ECM/UKMO to jump on board because this morning's ECM showed what looks like a cold cloudy dry south-easterly flow in FI.

[Coast]

Its time to put a line under this.

Ah yes that reminds me, Model Output Discussion

[Cecil Hogmanay Melchett]

Its soooo frustrating watching the models.Look at all the bitter air to our east but that stubborn atlantic

just forces the az high towards the UK effectively blocking the cold air.

At 120h i thought this run was much better to but even with the atlantic further west than 06z we still cant seem to get the cold stuff to us in the reliable timeframe.

[gottolovethisweather]

However, based on looking at those, personal interpretations about the outlook are made. Just as one example, as chionomaniac documents on the stratosphere thread, no MMW is the same, nor has the same effects in the same places every time.

Hello NSSC and others.

I love the thrill of this chase we are having with these models, will it, won't it etc. and after so much fun for coldies already in the bag we want more.

Anyway, geting to the point of my post is, please can you define MMW as by searching the web all I can find is something to do with "millimetre waves"

Please can you answer in basic plain english terms and i'll see if can learn something. Once again all the top posters are in here so keep it up guys n gals!

In my interpretation and others , also by studying the wonderful NW charts etc. I'm thinking that no WARMTH until at least mid february is on the cards, WOW take that raging zonality.

Wintry Cheers

STORMBOY

[Rollo]

I don't know, but it seems maybe you are trying to put forward a case for being the best forecaster around that there is

Let me put it this way, the data was there, but the ingredients were not yet as primed or able to potentially deliver (imo) to the same degree as they might now. It doesn't change the point that I am making that there was, and to quite a degree still is, no certainty that these factors would or will deliver a UK cold spell.

People such as me as well as other regulars on here always look at the northern hemisphere circulation pattern as a matter of course. But doing that doesn't guarantee a cast iron outcome like you seem to think it does - otherwise we would all be millionaire forecasters! lol!

However, based on looking at those, personal interpretations about the outlook are made. Just as one example, as chionomaniac documents on the stratosphere thread, no MMW is the same, nor has the same effects in the same places every time. Somethimes they have no effects at all. In fact none of the above factors you mention above, even in combination, guarantee a cold spell for the UK - even if the chances are of course enhanced. Just because they may potentially interact favourably doesn't automatically mean a big UK freeze

So unlike you, I personally was not nearly as assured about an imminent cold spell as you were./are. I would like to think that in the event, that decision has been reasonably well validated so far on the basis that the models have been over progressive with the evolution to the next (possible) cold spell. Not that it matters especially if it does or has been validated, as this is just for fun, and not a 'competition to win' as far as I am concerned.

Still, I have come a cropper like others before though in terms of letting hopes override realities and hence if I have learned anything at all from net weather and the valuable information and expert opinions available on here it is my decision these days to take a more measured and objective view instead of what I could still do and predict cold just because I want it to be cold.

I think that is perhaps a bit cruel Tamara,whilst you and I who have experienced the highs and lows while being members for several years CC is relatively new and does get a bit carried away from time to time,try to take into account the magnificent F1 charts we have been seeing and also bear in mind what has preceeded the current charts thus far this winter.With times come experience so I would encourage CC to continue in the same vein.

[Lewis]

12z downgrades the Northerly, it lasts 30 hours now. It's slowly vanishing....

[nick sussex]

The UKMO looks good tonight with shortwave heading se'wards at 120hrs, at 144hrs a definite upgrade from this morning.

[chionomaniac]

Its soooo frustrating watching the models.Look at all the bitter air to our east but that stubborn atlantic

just forces the az high towards the UK effectively blocking the cold air.

At 120h i thought this run was much better to but even with the atlantic further west than 06z we still cant seem to get the cold stuff to us in the reliable timeframe.

I think that the AH moving north is a critical trigger in helping this block westwards, HD.

Hello NSSC and others.

I love the thrill of this chase we are having with these models, will it, won't it etc. and after so much fun for coldies already in the bag we want more.

Anyway, geting to the point of my post is, please can you define MMW as by searching the web all I can find is something to do with "millimetre waves"

Please can you answer in basic plain english terms and i'll see if can learn something. Once again all the top posters are in here so keep it up guys n gals!

In my interpretation and others , also by studying the wonderful NW charts etc. I'm thinking that no WARMTH until at least mid february is on the cards, WOW take that raging zonality.

Wintry Cheers

STORMBOY

Try clicking on the link in my sig and all will be revealed SB.

[Iceberg]

12z downgrades the Northerly, it lasts 30 hours now. It's slowly vanishing....

But only because it keeps the cold air in place and transfers it to a ESE, SE or easterly flow and staying cold.

UKMET at 140 is bang on where it should be to support the easterly and colder evolution, this isn't out at 240 and really supports the general trend for a cold spell of continental air to spread across the UK from 5 or 6 days time onwards.

[Thundery wintry showers]

I think it depends on what one defines as the "northerly", because as far as I can see the Arctic airflow from the N or NW persists from midday Friday to midday Monday on this run- that's 72 hours. There is more like a 30 hour window for snow showers near some east coasts due to the specific wind direction, but even this is likely to be revised in the next few runs.

[nick sussex]

Its soooo frustrating watching the models.Look at all the bitter air to our east but that stubborn atlantic

just forces the az high towards the UK effectively blocking the cold air.

At 120h i thought this run was much better to but even with the atlantic further west than 06z we still cant seem to get the cold stuff to us in the reliable timeframe.

It might look frustrating but overall a step forward this evening, take a look at the UKMO 120hrs chart on meteociel, notice that shallow feature running se'wards through the UK thats the start of the change and its at 120hrs! we're not looking into FI for the first steps. We need as much margin for error though and want to see that Atlantic trough as far west as possible.

Edited January 28, 2010 by nick sussex

[Yeti]

The data was there a week ago, MMW, MJO,convection building over the date line, ridging into the Arctic,

hights moving across the pole and linking with the Siberian high, GLAAM and mountain torques predicted to

rise which you could see on the northern hemisphere charts,hints of fast downward propagation of easterly

winds in the stratosphere together with the warming and also remembering the initial response last year to a

sudden stratosphere warming (MMW)plus looking at the developing circulation pattern in the northern

hemisphere which I kept asking people to look at.

With the greatest of respect CC, if my memory serves me correctly you have been calling a return to cold ever since the end of the last cold spell - so, inevitably if/when it does return you will obviously be the first to have called it! As Tamara has already pointed out, the signs for a cold spell have not been (and still aren't) concrete, and February could quite easily have gone either way even though now a cold month is certainly favoured. IMO it is far too early to be celebrating forecasting victories, so let's just sit tight and see how things pan out. Even the northerly hasn't arrived yet, never mind any potential reloads from the East. This thread has, IMO, become quite polarised recently with two clear camps, which is a shame because judging by the comparative lack of posting with December, it is not just me who's decided to "lurk" instead of post.

As for the 12z, the HP doesn't get as far N as the 6z although I suspect that - as usual - the GFS is overdoing cyclogenesis and deepening those Atlantic depressions.

http://www.wetterzentrale.de/pics/Rtavn2041.png

Still, this is such a long way out that tiny changes in the short term will give rise to enormous long term changes, so it's almost useless looking at the 850 profiles as in the scheme of things these are small details that will become firmer later. Best keep an eye on the short to mid-term, particularly how the models are handling the troughing in Europe and upstream as this will be crucial to correct HP placement...

[Cecil Hogmanay Melchett]

It might look frustrating but overall a step forward this evening, take a look at the UKMO 120hrs chart on meteociel, notice that shallow feature running se'wards through the UK thats the start of the change and its at 120hrs! we're not looking into FI for the first steps. We need as much margin for error though and want to see that Atlantic trough as far west as possible.

ive looked at it nick and im not really impressed ?

At144 the high is still squashed over us!

[Bobby]

One has to say the 12z GFS and UKMO are an improvement on earlier. GFS shows some stunning synoptics into FI. ECM and GFS ensembles will be interesting.

[Harsh Climate]

Woohoo the charts are looking great

http://www.wetterzentrale.de/pics/Rtavn1561.png

Looks like people who were predicting/taking credit for a mild februrary are likely to have egg on there face.

[LomondSnowstorm]

Some pretty amazing FI charts from the GFS, but like the last cold spell the building blocks are in place a few days before the actual easterly. http://charts.netweather.tv/gfsimages/gfs.20100128/12/135/h500slp.png Like most major cold spells, the beginning of the evolution is height rises from the south. http://www.wetterzentrale.de/pics/archive/ra/2009/Rrea00120091211.gif http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910202.gif http://www.wetterzentrale.de/pics/archive/ra/1962/Rrea00119621222.gif

Nice UKMO as well http://www.meteociel.fr/ukmo/run/UW144-21.GIF?28-17

Seems to be more a matter of detail now - continental flow for late next week onwards seems almost nailed on.

LS

[gottolovethisweather]

I think that the AH moving north is a critical trigger in helping this block westwards, HD.

Try clicking on the link in my sig and all will be revealed SB.

Many Thanks Chionomaniac. I think a lot of that will go over my head but I get the gist of it, plus it's well written for folk like me to understand. Mr Chiono, what is your current take on the rest of winter according to the models/ensembles etc.?

I'm always keen to learn and understand our climate nuances as I'm sure, are many a lurker in here.

Maybe the next Laura Tobin or Michael Fish is reading these threads as we speak, so keep it together guys.

Cheers

STORMBOY

Edited January 28, 2010 by STORMBOY

[Frosty.]

One has to say the 12z GFS and UKMO are an improvement on earlier. GFS shows some stunning synoptics into FI. ECM and GFS ensembles will be interesting. :lol:

Yes the GFS 12z has everything further west so that milder air does not push east across northern britain like it did on the 6z, hopefully once the Northerly subsides, the cold air will remain intact so there is no thaw for the lucky areas which get a covering of snow this weekend. As you say, the FI synoptics are stunning and this wonderful winter continues the wow factor, hope the ECM 12z joins in the fun.

[Guest North Sea Snow Convection]

I think that is perhaps a bit cruel Tamara,whilst you and I who have experienced the highs and lows while being members for several years CC is relatively new and does get a bit carried away from time to time,try to take into account the magnificent F1 charts we have been seeing and also bear in mind what has preceeded the current charts thus far this winter.With times come experience so I would encourage CC to continue in the same vein.

I replied to his post addressed to me that was all. He has also questioned previously why I have not got excited about seeing an apparently obvious cold spell in the same way.

I have previously commented very postively in terms of some of the very interesting observations he has made. Cruel (for any faults I do have like most of us) I certainly am not. He is a very good new poster to the forum and knows infinitely more than I did as a newbie.

Back on topic - the UKMO looks very good this evening. The ECM this being an improvement on last night will be interesting to follow beyond t144 this evening, assuming It follows the UKMO. Good agreement with the GFS 12z for that time too.

Enjoy the output all

Edited January 28, 2010 by North Sea Snow Convection

[SP1986]

Woohoo the charts are looking great

http://www.wetterzentrale.de/pics/Rtavn1561.png

Looks like people who were predicting/taking credit for a mild februrary are likely to have egg on there face.

As will almost everyone else if this easterly doesn't occur or isn't as severe as perhaps someone would be led to believe if they were naive enough to believe everyone had a balanced view on the weather :lol: :lol:

I think certain people are right, although it does look like like an easterly is favoured, it wil never be even 80% certain until 2 days before the actual event starts. I do think the nature of the GFS does create a suggestion of a long easterly spell but that's to do with the 3 hourly/6 hourly time segments, depending on which models/part of the model you look at.

I don't believe myself that this certain yet, even if other members are getting excited. I do believe there will be come form of easterly, but a notable one I'm sceptical of yet.

[Iceberg]

Some fantastic Ensemble agreement from the GFS 12Z today at 168T for the Easterly to develop. You would have to be very brave/foolish to go against this. Particularly with the ECM agreement.

How about a pint for the first person that posts up a chart showing -20 850's somewhere in the BI. ?