Winter Model Discussion - 11/01/13 00z Onwards

[Cloud 10]

Long range ECM ensembles show the op run heading above the mean towards the end of its run.

[southbank]

in NH winters , specially in the current set up, FI is T 72 ........best to keep an eye on FAX and met and higher resolution if you are interested in where it snows

[Glacier Point]

The real developing story for me being the impending collapse of the polar vortex. We should be looking around day 9/10 for a complete cleaving in half across the Arctic with tropospheric reponse a few days later. A few GFS ensembles showing this.

Still looking very likely that the second phase of cold will come out of the NE.

Strog ensemble mean and teleconnective support for a deep trough to take up residence over Europe in the meantime, and also signal for low pressure in the Atlantic. ECM op not for me.

Edited January 11, 2013 by Glacier Point

[Methuselah]

And, in case anyone's feeling a whinge coming on...

[Gael_Force]

Like ECM 32 day report, JMA maintains strong northern blocking on its week 3/4 ensemble mean.

[Methuselah]

Lovely cross-model agreement at T+0...Loving this!!

[bradymk]

The real developing story for me being the impending collapse of the polar vortex. We should be looking around day 9/10 for a complete cleaving in half across the Arctic with tropospheric reponse a few days later. A few GFS ensembles showing this.

Still looking very likely that the second phase of cold will come out of the NE.

Thanks GP, GFS op also showed a beauty of an artic high before it went into low resolution. Any milder weather could be very short lived especially if you think a trop response d8-10

[Southender]

The real developing story for me being the impending collapse of the polar vortex. We should be looking around day 9/10 for a complete cleaving in half across the Arctic with tropospheric reponse a few days later. A few GFS ensembles showing this.

Still looking very likely that the second phase of cold will come out of the NE.

So are you thinking of a detached PV lobe out of Greenland, a transitionary cold zonal period then heights building in the GIN corridor giving a renewed cold shot from Scandi?

[al-Tikriti]

While we all debate the performance of the NWP I hope the opportunity will be taken to learn lessons from this most fascinating period of model watching. The volatility of the models and the record 'shannon entropy' will hopefully give us a chance to refine our knowledge of the models and refine our weather forecasting in the future. A post winter analysis will also help to point out the strengths and failures of the models in the face of this volatility.

The NWP of course is an attempt to predict the behaviour of a chaotic system and this chaos has been very evident this week. Lessons to be learned by both old and new weather watchers. British weather in particular never will be predictable or follow pretty patterns, unless of course that pattern follows fractal geometry LOL

Finally although the models have not fallen into lockstep, realistically we can expect a cold second half of winter. The chance of mild still exists but IMHO is receding fast.

[TEITS]

Dave

Justs look at 12z and 00z and even think of 00z yesterday, that is a huge switch by the ECM post 144, so I think its very fair, its plain awful medium term pure and simple. I'm not too bothered as the models are just not to be relied on and any solution is possible at present model wise.

BFTP

Sorry Fred I think I might of misread your post. I thought you were suggesting the 0Z ECM is like yesterdays GFS with your backtrack comment when that clearly isn't the case. The ECM at +120/+144 is massively different to yesterdays poor GFS runs.

Oould be wrong but I suspect this LP will be further W when it tracks S.

[Troubleatmill]

While we all debate the performance of the NWP I hope the opportunity will be taken to learn lessons from this most fascinating period of model watching. The volatility of the models and the record 'shannon entropy' will hopefully give us a chance to refine our knowledge of the models and refine our weather forecasting in the future. A post winter analysis will also help to point out the strengths and failures of the models in the face of this volatility.

The NWP of course is an attempt to predict the behaviour of a chaotic system and this chaos has been very evident this week. Lessons to be learned by both old and new weather watchers. British weather in particular never will be predictable or follow pretty patterns, unless of course that pattern follows fractal geometry LOL

Finally although the models have not fallen into lockstep, realistically we can expect a cold second half of winter. The chance of mild still exists but IMHO is receding fast.

Well said and put and do agree , doubt however that we will learn from this as the weather is somewhat like snowflakes as in two set ups are never the same...globally and its all linked. We can look at charts for our part of the world and say this looks very much like 1963 or 2010 or any set up...cold or mild, but it will not be the same and mesoscale changes are the 'flap of a butterflies wings' so to speak. hope the day comes where we 'nail' it, or should say the Pro's nail it with supercomputers but sure we are a million miles from that yet.

Learn from taking runs at face value definately, think we always try to, but when it shows great charts, the kid in you comes out and you get excited, errrr well i do anyway

i will grab my coat......Taxi!!!!!

Edited January 11, 2013 by Nick JB

[Southender]

Looks like a slight Northward correction for the Rain/Sleet/Snow band on Sat morn/afternoon to me.

Edited January 11, 2013 by Shrimper

[TEITS]

Latest NAE suggesting snow showers moving into the NE, Yorks, Humber, Lincs.

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2013/01/11/basis06/ukuk/prty/13011306_1106.gif

[Southender]

Visible Westward shift for Mondays possible snow as well.

With the colder air digging in much quicker for all areas.

Edited January 11, 2013 by Shrimper

[WhiteFox]

While we all debate the performance of the NWP I hope the opportunity will be taken to learn lessons from this most fascinating period of model watching. The volatility of the models and the record 'shannon entropy' will hopefully give us a chance to refine our knowledge of the models and refine our weather forecasting in the future. A post winter analysis will also help to point out the strengths and failures of the models in the face of this volatility.

The NWP of course is an attempt to predict the behaviour of a chaotic system and this chaos has been very evident this week. Lessons to be learned by both old and new weather watchers. British weather in particular never will be predictable or follow pretty patterns, unless of course that pattern follows fractal geometry LOL

Finally although the models have not fallen into lockstep, realistically we can expect a cold second half of winter. The chance of mild still exists but IMHO is receding fast.

The chances of people learning from this experience are as low as the chances of a repeat of 1963, especially given some of the comments I've read this morning!

Anyway, looking good for early next week now with Monday into TUesday looking very interesting. I like the way that the FAX for Monday shows that the front has mostly occluded as it comes down so the warm sector is mostly mixed out. As for beyond Wednesday, I might as well go and draw a chart myself given how uncertain the outlook really is; chances are it would verify almost as closely as some of the model output at 168 hours!

[Orpingtoniceagedec10]

Please don't delete this message again , its a genuine question , model related . Could someone please tell me what a short wave is and why it is sometimes good and sometimes bad from a coldies point of view ?

This isn't the place to be asking these questions, it moves too quickly, and the team are trying to keep things on track, so your posts will either get lost in the sands of time, or be removed. Try asking in the weather discussion areas - and have a look here too http://weatherfaqs.org.uk/node/144#Shortwave

Edited January 11, 2013 by IanM
Just being helpful

[ICETAB]

Snow event Monday night into Tuesday for many on the 06Z GFS. Cold air stays a bit further west.

[Liam J]

A more progressive set of runs from the BOM, NOGAPS & GEM 00z's, a little concerning to see after these models were standing firm against attacks from the west. Just something to bare in mind. GFS potentially heading down that road on the 6z!

Looking good in the short term over the weekend and early next week.

Edited January 11, 2013 by Liam J

[Summer Sun]

Snow charts for Monday tea time

Just before the Tuesday morning rush hour

By 18:00 Wednesday

Friday 18:00 next week

[TEITS]

Looks like a poor GFS op coming up with the whole lot starting to already flatten out.

Still we will see how this all turns up later on, models are more or less cluless anyway past Monday.

That isn't how im reading the 06Z. Fully expecing another system to track SE on the nexr frames.

[nick sussex]

A messy wintry picture shown by the GFS 06hrs run so far.

The output today so far really is all over place with little confidence in any of the detail.

[kold weather]

That isn't how im reading the 06Z. Fully expecing another system to track SE on the nexr frames.

http://modeles.meteo...gfs-0-108.png?6

It may well do, the problem is we are by that time pretty much out of the cold air, that solution screams of rain and wintry stuff over the hills if that was to happen as per the GFS.

Not as good as the 06z for snow chances, though Monday/Tuesdays band still looks good.

It doesn't matter much though, because the models will probably look different again by the 12z suite is complete!

Edited January 11, 2013 by kold weather

[Snowmad79]

Latest NAE suggesting snow showers moving into the NE, Yorks, Humber, Lincs.

http://expert-images...011306_1106.gif

Nice little upgrade from the NAE since its 00z. That could well be a streamer, pushing snow across the Pennines into some of the Northwestern areas. Happened last Winter and gave my area 15cms. Not sure if the flow is strong enough mind.

Edited January 11, 2013 by Snowmad79

[East Herts Snow]

Please don't delete this message again , its a genuine question , model related . Could someone please tell me what a short wave is and why it is sometimes good and sometimes bad from a coldies point of view ?

Hi Orpingtoniceagedec10, try this link below as it provides a learner guide on short waves:

http://www.theweathe.../habyhints/131/

This is another link to a previous thread on the Netweather Forum:

http://forum.netweat...twave-features/

Edited January 11, 2013 by East Herts Snow

[warrenb]

Strat finally feeding into the trop, should be around the 96 hr mark that this begins, so confusion will reign I am afraid.