Model output discussions pm 31/12/15

[Ali1977]

Whatever happens in FI is still up for grabs, however by this time next week the air Weill definitely feel the coldest of this winter.

[northwestsnow]

3 minutes ago, bluearmy said:

The mobile Atlantic amplification looks favoured for the time being. I'm not seeing any strong evidence for ridging through Greenland though that isn't to say it won't be possible at all. A lot of pressure from the Canadian lobe of the vortex means that a sustained height rise is more likely around Iceland eastwards if it to happen.

certainly going to feel a lot more seasonal and i suspect Exeter waiting for the overnight extended ens runs before changing  the gist of their 6/10 day output.

we have no idea if MOGREPS sees this. If it doesn't, they will stay ultra cautious. 

EXACTLY what i mentioned during the run, thanks Blue

[Ali1977]

Cold enough for snow for most of the Country at days 7-10 with Atleast -6c uppers, away from coasts anyway. Would we get decent frosts in a Northerly flow???

[nick sussex]

6 minutes ago, Mucka said:

The block certainly doesn't topple but the original ridge does in a sense with energy pushing under the tip of Greenland which conversely helps sharpen the pattern behind.

I am happy that the upstream remains amplified to give us a second chance but weary that the 1st attempt doesn't really succeed in fully cutting off the Atlantic.

Turns out to be a stonking 10 day chart anyway which I guess is what counts in the end.

I'm just going to have my evening cup of Horlicks! lol and I'll be doing my rounds of the NCEP state forecasts to see what they have to say.

The ECM could have made things less dramatic if it deepened the low at T168hrs, this would have built better heights towards Greenland. Instead it dragged out the drama. Its difficult given the dire winter so far to be too picky, if people were offered anything like the ECM upto T216hrs during December they would have been very happy. Glass half full IMO, it would be nice to have it overflowing but we'll see over the next few runs.

Edited January 4, 2016 by nick sussex

[Glacier Point]

4 minutes ago, bluearmy said:

The mobile Atlantic amplification looks favoured for the time being. I'm not seeing any strong evidence for ridging through Greenland though that isn't to say it won't be possible at all. A lot of pressure from the Canadian lobe of the vortex means that a sustained height rise is more likely around Iceland eastwards if it to happen.

Unless of course if the trough slides out through the Atlantic south-east being the catalyst for our proper -NAO flip......could well be our torpedo surfacing before it strikes its target.

[northwestsnow]

Just now, Ali1977 said:

Cold enough for snow for most of the Country at days 7-10 with Atleast -6c uppers, away from coasts anyway. Would we get decent frosts in a Northerly flow???

Certainly

 

[mountain shadow]

4 hours ago, Spah1 said:

Hopefully the MO will change their 'brief' cold spell in the next couple of days to something more sustained.

It will all depend on the overnights I think.

Decent runs tonight. ECM with 4 days of sub -5 850s followed by something more prolonged. 

Winter hangs in the balance. 

[chris55]

Excellent ECM tonight. ties in well with the GEFS 12z, the 850s at 192-216-240 are all below -5 for London and the reload looks in place to continue those kind of temps or perhaps colder!

 

[bobbydog]

talk about pattern change... i just ran the animation of the ECM on meteociel, the pattern changes on every frame! have the ECM team factored in all-out nuclear war??

[nick sussex]

Just now, mountain shadow said:

It will all depend on the overnights I think.

Decent runs tonight. ECM with 4 days of sub -5 850s followed by something more prolonged.

Winter hangs in the balance.

And so does the mental wellbeing of the many cold and snow lovers in this thread! I'm in no mood for an England penalty shoot out fiasco.

Time will tell whether this is a cold snap or decent spell. Still a lot of water to run under the bridge most of all whether the ECMs last gasp victory is the way forward or whether some other route might open up like in GP's post.

[IDO]

Another ECM run another possible outcome.

What we have learnt over the last 48 hours is seeming good sustainability for a Kara High. That is a good positive and will allow further bites of the cherry.

Also ECM has trended towards the initial WAA linking the EPO with the Russian HP which is disappointing as the extra CAA would have allowed further cold to move south (UK/Euro region). Instead the CAA is pushed into the trough over the US, sinking the upper cold and aiding the development of further low pressure. Of course the coldies in the US will take our misfortune:

That blows up the trough, but with the longevity of the upper low in the Atlantic we get a further wave of WAA from the Atlantic by D10. The GFS has been playing with that upper low west of the Azores since yesterday so it is a possibility, and probably needed if we get the initial cross flow from the EPO to Russia. Lots of ball juggling here from ECM to get that cold and I suspect this is not the final solution. Hopefully there is still time for a return to the initial Kara/Arctic High to link with the Atlantic>Greenland Ridge as this will divert the cold uppers to the Euro region, ideal for possible Scandi/Icelandic blocks down the line. Still a good cold run from the ECM with snow possible for even the Duchy during that run.

[Frosty.]

Makes a very nice change not to see those red charts knocker has been posting through winter so far...Bring on those dark blues from the Ecm 12z!! First nationwide cold spell could be ours next week!!

[ANYWEATHER]

Coldies should be at least a little happier tonight , with both ecm and gfs shows the North Pole warming and displacing the cold to lower latitudes . Both in agreement tonight, should at least be a good sign. Theres no point at this stage on trying to pin details down, but lets get the cold in first and go from there. If the models are right some places will get plastered with snow with these synoptics........... Well after all its Winter.

Edited January 4, 2016 by ANYWEATHER

[mcweather]

It might seem churlish but I preferred last nights  ECM cross polar flow, in terms of getting the cold here and more importantly keeping it going.

However after the crap we have had to put up with for the past two months then I,d take four days of sub -5 850's and a possible reload as a start.

Just imagine if this progged cold snap could hold on until GP,s torpedoed vortex towards the end of the month

 

[knocker]

There are two periods of snow on the ecm run both on fronts as they move NE over Scotland  One on Weds/Thurs which gives quite substantial falls in Scotland and some on high ground in N. England. And Saturday with a similar outcome. That's about it for snow but quite a severe frost towards the end of the run as a brief northerly regime sets in as the low moves away east and the ridge moves in from the south west. That of course is subject to change.

Oh and I'm still having a little dabble in the woodshed Frosty.

Edited January 4, 2016 by knocker

[booferking]

2 minutes ago, knocker said:

There are two periods of snow on the ecm run both on fronts as they move NE over Scotland  One on Weds/Thurs which gives quite substantial falls in Scotland and some on high ground in N. England. And Saturday with a similar outcome. That's about it for snow but quite a severe frost towards the end of the run as a brief northerly regime sets in as the low moves away east and the ridge moves in from the south west. That of course is subject to change.

Is there no chance people in the north will see snow on day 7,8,9,10??

[gottolovethisweather]

43 minutes ago, knocker said:

There are two periods of snow on the ecm run both on fronts as they move NE over Scotland  One on Weds/Thurs which gives quite substantial falls in Scotland and some on high ground in N. England. And Saturday with a similar outcome. That's about it for snow but quite a severe frost towards the end of the run as a brief northerly regime sets in as the low moves away east and the ridge moves in from the south west. That of course is subject to change.

Are the two dates you mention +Knocker concerning this week or next?

As if it is the former I have been keeping a keen eye on the Friday/Saturday event for a couple of days now, as illustrated by this post for one, am pleased to see this still being a viable event, even if short-lived and transient. The charts offering up the best potential for coldies still remain slightly out of reach beyond the 11th/12th January. However we are seeing signs of consistency in this latter aspect, so my wintry hopes are tentatively building by the day let's say. 

Edited January 4, 2016 by gottolovethisweather

[knocker]

5 minutes ago, booferking said:

Is there no chance people in the north will see snow on day 7,8,9,10??

Of course there is a chance I just posted what the ecm is showing, not that that is reliable certainly in that time frame.

Edited January 4, 2016 by knocker

[knocker]

6 minutes ago, gottolovethisweather said:

Are the two dates you mention +Knocker concerning this week or next?

As if it is the former I have been keeping a keen eye on the Friday/Saturday for a couple of days now, as illustrated by this post. The charts offering up even more potential still remain slightly out of reach beyond the 11th/12th January, however we are seeing signs of consistency in this latter aspect so my wintry hopes are tentatively building let's say.

This week.

[Frosty.]

1 minute ago, knocker said:

Of course there is a chance I just posted what the ecm is showing, not that that is reliable certainly in that time frame. It's frankly not worth paying too much attention at this stage IMO.

I would say there is strengthening support for our first nationwide cold outbreak next week, it's what the models are showing and the met office have mentioned plus GP fired a torpedo so it's all looking good for coldies for the first time this winter..almost time to turn down the AC in the woodshed and light that wood burning stove

[i luv snow]

3 minutes ago, knocker said:

Of course there is a chance I just posted what the ecm is showing, not that that is reliable certainly in that time frame.

And of course, the ECM shows 4 days of temperatures cold enough for snow, and as we all know, any finer details (if this evolution or something similar came to fruition) would not be known until much nearer the time. We have all been caught out/pleasantly surprised by unexpected snowfall in the past, so just getting the cold is the first big step!

[knocker]

Just now, Frosty. said:

I would say there is strengthening support for our first nationwide cold outbreak next week, it's what the models are showing and the met office have mentioned plus GP fired a torpedo so it's all looking good for coldies for the first time this winter..almost time to turn down the AC in the woodshed and light that wood burning stove

I wasn't referring to the cold Frosty just the snow as the cold interlude looks quite dry.

[weirpig]

3 minutes ago, knocker said:

I wasn't referring to the cold Frosty just the snow as the cold interlude looks quite dry.

but in your summary of the ecm  you said that there may may be harsh frosts  as the uk is under the influence of a brief northerly. Now i maybe very ignorant here but the later frame of the ecm suggests something more sustained. Is there any reason by looking at the ecm charts ypu believe it will on be a brief northerly?

[phil nw.]

Not a bad set of gefs ,slighty colder than the 06z set for c.England.

with a continuing trend for the colder air to land around the 13th from that Atlantic ridging.

Actually the mean at that time is quite relevant based on the temp/pressure graphs above.

the picture i get from those ens is for a cold north/north westerly and as the Atlantic ridge moves  east towards the UK the flow get's cut off after 3-4 days but we would retain surface cold air for some days after under building pressure.

It doesn't look a classic Northerly at the moment and the advection of the cold south could well be quite messy with shortwaves developing which would modify the true Arctic air. At this stage widespread lowland snow looks unlikely unless that Greenland ridging suddenly amplifies to a greater degree than currently modeled and we see a sharper dig of deeper cold coming south.

The overall picture is still promising though with the Arctic profile much better with splits showing across the polar vortex so if we miss out somewhat next week it could well be that GP.'s torpedo will do the job a little time after.

[knocker]

Just that the evolution has the wind backing northwesterly as the UK get's into the circulation of the Azores HP which itself is swinging on it's axis.. This is really a bit academic as no doubt the surface analysis for this period will be slightly different in a couple of days time.

Edited January 4, 2016 by knocker