Model Output Discussion 17th Dec.2013-12z onwards.

[garbagebags]

With regards to the stratosphere-

 

Its totally the wrong thing to do to remove links/ images to the strat from this thread- As people are learning all the time & images will help that process & well as introduce people to thought of including it in their thought processes-

 

Its very straight forward- we have 3 threads already live.

 

All there needs be is-

General model discussion- which includes the usual links/banter/ stratosphere anything goes type posts

 

Indepth model thread

Indepth Stratosphere thread.

 

Job done.

 

S

 

PS cra**y 06z Ensembles- nothing like the ECM-  11/12/18 are the only ones of slight interest.

Lets hope the GFS is as useless as it was on the last eastwerly set up which was Feb last year....

 

Why would strat posts be removed from this thread? It is the stratospheric model the exact same as any other model. It is a model and this is the model thread. It would be like saying you can post ECM but not GFS. 

[Timmytour]

My impression was that Chio was relating to speculation about what changes in the stratosphere might do to models who were not as yet responding to them when he suggested they should not form part of the discussions here. I can see the logic in that. Am i right to believe that the models can only respond to SSW that's occured rather than is forecasted?

[johnholmes]

correct

 

all models run on current data NOT what any model at whatever level may be predicting.

[Mucka]

Absolutely no way to make a judgement where the output is going at the moment with so much divergence between models still in such a relatively short time-frame. Not only that the models are giving completely conflicting signals. ECM resolute with its Atlantic ridge, UKMO resolute with its flatter pattern and GFS resolute with building a stronger Scandinavian ridge but with operational's disinterested in the Atlantic ridge and that is just out to day 5/6!

 

Actually I am surprised that nobody else seems interested to comment on the clear trend of GFS output of late regarding heights to our NE and how the pattern is being backed West given this is only 5 days out and if continued could have important implications for the upstream pattern.

Here are the last 5 Operational runs from just 06z yesterday inclusive. 

 

 

 

So we have ECM amplifying the pattern to the West while GFS is amplifying the pattern to the East and UKMO is amplifying neither!

Let's hope ECM is correct out West, GFS is correct out East and UKMO is just plain wrong.

[Polar Maritime]

My impression was that Chio was relating to speculation about what changes in the stratosphere might do to models who were not as yet responding to them when he suggested they should not form part of the discussions here. I can see the logic in that. Am i right to believe that the models can only respond to SSW that's occured rather than is forecasted?

 

B.A said the models take into account the warming model'd in low res..  Hope im correct.

 

Yes Mucka as i said early'er a growing trend reg GFS.

Edited January 1, 2014 by Polar Maritime

[johnholmes]

B.A said the models take into account the warming model'd in low res..  Hope im correct.

not as far as I know PM, see my post above

 

best ask either Jo or Ian F what they say in Exeter as all model centres will run their models in a similar fashion?

[Polar Maritime]

not as far as I know PM, see my post above

 

best ask either Jo or Ian F what they say in Exeter as all model centres will run their models in a similar fashion?

 

My brain is not very good this morning for one reason, or another so sorry if i have misquoted B.A.

[bluearmy]

not as far as I know PM, see my post above

 

best ask either Jo or Ian F what they say in Exeter as all model centres will run their models in a similar fashion?

 

in perspective - the model (be it gfs or ecm) has the troposphere and stratosphere running as one large dynamic of small boxes.  there are images on the ecmwf website to illustrate this.  there are 137 vertical levels of boxes on the ecm op model and 91 on the ecm ens model. the boxes are also smaller on a horizontal scale on the ecm model than the gfs model (see the thread on model resolution for further info). given the extra vertical levels on the ecm model, than the gfs, it has more definition (ie the size of the vertical aspect of these boxes) in the stratosphere (or if you like, the upper part of the dynamic model) than the gfs.  so the starting data is set and the model then goes off to calculate the next x number of hours.  it only has the starting data and if it develops events in the strat, it is in tandem with what it is showing in the trop as it is all one model of the atmosphere.  the size of the boxes does not change throughout the ecm op run whereas on gfs op, they get larger after T192. (imagine what that can do to the complex calculations being undertaken within these boxes to determine what is happening to the air inside them). it is no surprise that the gfs op run can become odd post T192 in comparison with what was showing at that timescale. 

 

so to go back to PM's point, if the model creates a SSW during its run, it will carry on modelling its effects. it has no idea what it is creating - it is just calculating what happens to the air inside the boxes and their interaction with all the boxes adjacent to them. 

 

the thead on model resolution is to be found here

 

http://forum.netweather.tv/topic/72326-model-resolution/

Edited January 1, 2014 by bluearmy

[nick sussex]

What a nice surprise that ECM was followed by the letdown of the GFS and UKMO which develop low pressure too far east, this current uncertainty upstream is very common with these types of situations, you will rarely get good agreement when you're dealing with an interaction of Gulf moisture and the northern stream energy.

 

The phase point is critical and also the timing, you need the right interaction at the right time, after the morning uncertainties we could have hoped perhaps for a little nudge by the GFS 06hrs run towards the ECM to give us a bit more confidence in that but the 06hrs run is even flatter than the 00hrs so it's going to be a long wait now till tonights outputs.

 

In terms of trying to find some clarity I've looked at the latest State forecasts, now generally they still expect an inland runner, but how much inland is the key here, then looking at the Illinois forecast this is in the crucial Midwest where the the track would be quite important especially if the ECM was to verify:

 

Firstly from the Illinois state forecast:

 

THINGS BECOME A BIT MORE INTERESTING GOINGINTO SUNDAY AS THE UPPER TROUGH CONTINUES TO AMPLIFY HELPING ASURFACE INVERTED TROUGH TO FOCUS INTO THE OHIO VALLEY THEN ORGANIZEWHILE MOVING NORTHEAST. THIS OCCURS IN MUCH CLOSER PROXIMITY TO THEAREA THAN EARLIER RUNS INDICATED AND SUSPECT THAT FURTHER SHIFTSWILL OCCUR...WITH GUIDANCE HAVING COMMONLY BEEN TOO FAR SOUTHEASTWITH SIMILAR FEATURES THIS WINTER AND ULTIMATELY BRINGING THEMFURTHER NORTHWEST. THIS WILL OF COURSE BE DICTATED BY THE EVOLUTIONOF THE DEEPENING UPPER TROUGH.

 

We want developments to be held back further west so that's a positive, this from Ohio is really the best news I've seen re this low and certainly if you view this in the context of the very flat GFS 06hrs run then you'd think that its unlikely to verify:

 

MODELS ARE STARTING TO COME INTO AGREEMENT WITH THE DEVELOPMENT OF ALOW PRESSURE SYSTEM THAT WILL MOVE NORTHEAST ALONG THE COLD FRONTSUNDAY AT THE SURFACE. THE STORM SYSTEM IS EXPECTED TO INTENSIFY ASIT MOVES INTO THE REGION. WARM AIR ADVECTION WILL TAKE PLACE OVERTHE EASTERN UNITED STATES AHEAD OF THE STORM SYSTEM AS UPPER LEVELTROUGH BECOMES NEGATIVELY TILTED OVER THE EAST AS WELL. AS WARM AIRINTERACTS WITH THE ARCTIC AIR PLUNGING SOUTH...POTENTIAL EXISTS FORRAPID INTENSIFICATION OF THE LOW.  IT MAY BE POSSIBLE THAT THEMODELS JUST HAVE NOT CAUGHT ON TO THE INTENSIFICATION YET. SOME OFTHE BIGGEST STORMS FOR THIS AREA ORIGINATE OUT OF THE GULF COASTREGION WHEN AN EXTREME COLD AIR OUT BREAK TAKES PLACE.

 

Bearing in mind here that we want the storm to deepen rapidly over the interior to force this more ne rather than out into the Atlantic.

 

Below are comparisons of the WPC forecasters view at Midday Monday and the GFS 06hrs run to the same time:

 

WPC

 

 

GFS

 

 

NOAA in their extended discussions went with the ECM ensemble mean and that's reflected in their charts, the day 6 takes the low centre between Hudson Bay and Quebec, compared to the GFS which has it off shore to the north of Newfoundland:

 

WPC

 

 

GFS

 

 

 

You can see the GFS is already beginning to phase it with the low near the UK, I think the GFS 06hrs run is very much an outlier solution.

 

Anyway we'll know in a few hours time whether the ECM output is a starter in terms of that possible Scandi high.

 

 

 

 

 

 

[bluearmy]

shades of last month nick when ecm turned out to be too far nw with that track. lets hope it has this one right.

[nick sussex]

shades of last month nick when ecm turned out to be too far nw with that track. lets hope it has this one right.

 

Yes I think the sensible way forward is the ECM ensemble mean, that will take into account some of its bias, on the other hand though its an interesting set up especially with those comments from the Ohio state forecast, if the operationals of the other models are under doing the deepening then that would give a bit more support to the ECM.

 

I think I'll stay on the fence here, I would love the ECM to be right but have similar reservations as yourself.

[Northern Sky]

With regards to the stratosphere- Its totally the wrong thing to do to remove links/ images to the strat from this thread- As people are learning all the time & images will help that process & well as introduce people to thought of including it in their thought processes- Its very straight forward- we have 3 threads already live. All there needs be is-General model discussion- which includes the usual links/banter/ stratosphere anything goes type posts Indepth model threadIndepth Stratosphere thread. Job done.

I really agree with this Steve. It's perfectly reasonable for people to want to comment on the stratospheric output of each model run and the fast moving pace of the model output thread seems to me to be a better place for short comments/ reactions than what should be a more in depth Stratosphere thread.The Strat thread has done much to enlighten myself and many others over the last few years and I'm not sure it's the best place to post one liners on the ups and downs of each model run.

[shedhead]

Yes I think the sensible way forward is the ECM ensemble mean, that will take into account some of its bias, on the other hand though its an interesting set up especially with those comments from the Ohio state forecast, if the operationals of the other models are under doing the deepening then that would give a bit more support to the ECM.

 

I think I'll stay on the fence here, I would love the ECM to be right but have similar reservations as yourself.

I think anyone who has watched the big two battle it out post T+192hrs so far this Autunm/Winter will have more reservations than the entire Sioux nation ever had over ECM's evolution. Personally I think we will end up with something of a half way house come later next week, with the Atlantic train slowing and gradually getting shunted towards a siding somewhat farther north, but I'm still not convinced the Trans Siberian Express will be leaving anytime soon with Galway on the board as it's final destination. 

Edited January 1, 2014 by shedhead

[nick sussex]

I think anyone who has watched the big two battle it out post T+192hrs so far this Autunm/Winter will have more reservations than the entire Sioux nation ever had over ECM's evolution. Personally I think we will end up with something of a half way house come later next week, with the Atlantic train slowing and gradually getting shunted towards a siding somewhat farther north, but I'm still not convinced the Trans Siberian Express will be leaving anytime soon with Galway on the board as it's final destination. 

I have to agree re the ECM, it has been a big let down in terms of reliability this winter so far from 168hrs onwards, the situation here is one of those domino type things, essentially here what happens around 120 to 144hrs upstream will likely dictate everything else either falling into place or being derailed.

 

The complexity of the upstream shouldn't be underestimated here, you have shortwave energy running across the south from the west as this heads east it picks up moisture from the Gulf of Mexico which in turn gets thrown north into the  PV and troughing over Canada.

 

So its the interaction and timing that could see either a weaker system developing or a rapid deepening as the Arctic air meets that moister warmer air, the amplitude of that troughing over Canada is important because this is what helps phase the two parcels of energy together.

Edited January 1, 2014 by nick sussex

[ARNOTT ad]

Met office outlook forecasts are very interesting and exciting!!

[shedhead]

I have to agree re the ECM, it has been a big let down in terms of reliability this winter so far from 168hrs onwards, the situation here is one of those domino type things, essentially here what happens around 120 to 144hrs upstream will likely dictate everything else either falling into place or being derailed.

 

The complexity of the upstream shouldn't be underestimated here, you have shortwave energy running across the south from the west as this heads east it picks up moisture from the Gulf of Mexico which in turn gets thrown north into the  PV and troughing over Canada.

 

So its the interaction and timing that could see either a weaker system developing or a rapid deepening as the Arctic air meets that moister warmer air, the amplitude of that troughing over Canada is important because this what helps phase the two parcels of energy together.

Very much so Nick, it's a situation almost akin to the development of an Easterly, whereby all the parts of the jigsaw have to fall into place at pretty much exactly the right time.  Stranger things have happened of course, but pinning any hope on it at this stage looks a tad foolhardy to say the least imho. 

Edited January 1, 2014 by shedhead

[lassie23]

Met office outlook forecasts are very interesting and exciting!!

UK Outlook for Thursday 16 Jan 2014 to Thursday 30 Jan 2014:

Current indications suggest that the recent unsettled conditions will persist at first. However there are then some signals that the weather may undergo a change later in this period, as colder conditions become increasingly likely. This would increase the risk of some wintry conditions developing during the second half of January, although mainly across the northern parts of the UK. This also indicates the potential for more settled conditions, bringing less in the way of windy and wet weather by the end of the month.

Updated: 1147 on Wed 1 Jan 2014

 

I live down south

[shedhead]

 

UK Outlook for Thursday 16 Jan 2014 to Thursday 30 Jan 2014:

Current indications suggest that the recent unsettled conditions will persist at first. However there are then some signals that the weather may undergo a change later in this period, as colder conditions become increasingly likely. This would increase the risk of some wintry conditions developing during the second half of January, although mainly across the northern parts of the UK. This also indicates the potential for more settled conditions, bringing less in the way of windy and wet weather by the end of the month.

Updated: 1147 on Wed 1 Jan 2014

 

I live down south

 

On the face of it an improvment for sure, but worth noting the few key bolded words imo. Perhaps not unexpected cautionary wording at this range, but still best kept in context for now imo.

Edited January 1, 2014 by shedhead

[nick sussex]

Very much so Nick, it's a situation almost akin to the development of an Easterly, whereby all the parts of the jigsaw have to fall into place at pretty much exactly the right time.  Stranger things have happened of course, but pinning any hope on it at this stage looks a tad foolhardy to say the least imho. 

At some point maybe our luck will change! the ECM scenario is plausible if upstream events play ball especially as you see it developing low pressure near the Azores, however it has had a bias for the last few winters of being overamplified in the later timeframes, the opposite of the GFS which is often too flat and progressive.

 

I wouldn't like to call this one!

[phil nw.]

Good afternoon all.

If you just hold off posting anymore for a minute or two i will open a new thread.

[phil nw.]

OK then new thread here

http://forum.netweather.tv/topic/78936-model-output-discussion-1st-january-2014-06z-onwards/

 

Locking this now.