WInter Model Output Discussion 12z- 28/01/2013

[East_England_Stormchaser91]

Will be good to see that azores high make itself useful and hook up with the Greeny High.

I reckon this winter is far from over yet, and we may well see some more disruptive snow and possibly in a more convective nature too, should another decent cold blast occur.

You know the saying, 'as the days get longer, the cold grows stronger.' Watch this space everyone.

[Stour7]

Very good and to the point. I also agree with what you say...But PLEASE can everyone get back to the models?

Very good point, however lots of people looking on this thread, with limited knowledge are too scared to post anything.........

[Panayiotis]

Before the 12z comes out I just want to mention again the ensembles are looking good post 228hrs, with the Azores ridging north and the low to the east, we are in a constant, cooler flow. One thing to note are the low-ish heights over Spain as the run progresses, as long as we have this, a colder and less zonal outlook is always on the cards. Few tweaks here and there and we could be looking at the Azores ridging into Greenland properly and then we will have the true GH. As long as we see these ensembles approach us instead of just staying at this timeframe, cooler/colder prospects look good.

Edited January 28, 2013 by Panayiotis

[Methuselah]

Very good point, however lots of people looking on this thread, with limited knowledge are too scared to post anything.........

Don't be. We have all sorts of different viewpoints...

[Stour7]

Don't be. We have all sorts of different viewpoints...

Don't mean to be off topic, but your comment is much appreciated, I am learning a lot as others have also said, have found this winter fascinating & have been reading this & the strat thread & have found many posts very educational,

Regards

N

[Mair Snaw]

Hi First post on here after a short time watching and reading trying to get a handle on the outputs, really good thread this and i think some of the more senior posters have given me a real good few weeks of model watching, just a shame that some get a bit caught up in it so much, i understand that people have hopes etc for winter and its good to see a difference of thought, I for one am a life long lamp post watcher and snow/cold fan. i hope for a BIG SNOW event in the next month or so, thats even after over 40cm IMBY in the last two weeks. Guys keep up the great work and keep this thread worth tuning into every day/night.

[lorenzo]

CPC summary for today rock solid on the pattern for days 6-10 citing well above average then days 10-14 4/5 for 'fair agreement' on models used.

Ensembles centred on the following days D8 / D11

Main product

Super Ensemble mean

North Atlantic heights a dominant feature here, however the analog composite painting a very different picture? Always subject to change and tweaks day to day, still interesting to see how they blend the models together.

ECM 00z mean weighted heavily as was GEM 00z for outcomes post 168 / 192 hrs. No agenda here. Just posting up the charts, for me perhaps reflective of the vortex lifting out, the 100hpa analysis chart also of interest today bearing in mind that rotten area spewing out energy recently.

[Isabellesnanny]

Don't be. We have all sorts of different viewpoints...

I agree - I am a newbie and a bit of a lurker here but I too feel a bit nervous about posting unless enthusing about a major cold event being on the horizon. Again I am learning a lot but there does seem to be a lot of negativity against posts that aren't ramping up a certain type of weather.

[phil nw.]

Tonights CPC forecasted anomalies show the AH easing west and with better ridging -compare the 2 charts.

http://www.cpc.ncep....y/610day.03.gif

http://www.cpc.ncep....y/814day.03.gif

they comment on this in their summary

8-14 DAY OUTLOOK FOR FEB 05 - 11 2013

THERE IS OVERALL GOOD AGREEMENT ON THE FORECAST CIRCULATION PATTERN FOR 8-14

DAY PERIOD. THOUGH THE RIDGE OVER THE NORTH ATLANTIC INCREASES SLIGHTLY IN

AMPLITUDE FROM THE 6-10 DAY PERIOD, THE RIDGE IS FORECAST TO MOVE SLIGHTLY

WESTWARD IN THE 8-14 DAY FORECASTS.

http://www.cpc.ncep....day/fxus06.html

which is what we want to see to reduce the influence of milder air coming around the top of the High within any SE tracking lows.

Edited January 28, 2013 by phil nw.

[Panayiotis]

At 69hrs and the PV over the West of Greenland seems to be much weaker compared to the 12z, this is bound to help us with getting the cold!

Edited January 28, 2013 by Panayiotis

[bluearmy]

i think far too much being made of greenland highs. with a strong euro trough in place, why do you need a greenland high ? if the atlantic ridge is too close, then the energy riding over the top is bound to introduce pm incursions into the mix. however, cpc seem to want to retrogress the ridge somewhat so i cant see a massive problem getting the jet to drop to our west. alternatively, there is a cluster of gefs runs (and no doubt ecm also) that extend the ridge ne towards scandi at times. that would mean any energy riding over the top has to come in from a more north/northeastern direction and any pm sector will hopefully have been mixed out by the colder longer routing. anything feasible but no reason to be too downbeat about a cold period beginning sometime after the 7th feb.

[Jaffusmaximus]

Appears to me another slight adjustment West on this run, I wonder what the cumulative effect would be if these continue until the weekend?

[Panayiotis]

Oh the joy,normally its the inverse with mild air!

[Penrith Snow]

Steve M I feel is quite right in what he is saying of no real cold in the next 10 days. However I still feel the real potential for a more sustained period of cold comes post D10. As long as you keep low pressure to our south in the med, it is quite hard to get mild weather for the UK and the models keep going with the trend of lowering heights to our south and amplifying the flow with a mid atlantic ridge ridging northwards. However as we have noticed this winter, greenland heights have been elusive due to dominant low heights to our north west so is this another period where higher heights modelled to our NW never come into a short timeframe or will we see our first good greenland high of the winter. MJO is looking great aswell as the many other teleconnections GP has posted but will they deliver? I hope so.

I dont think Steve has ever got over the Great December let down and I dont blame him really it was a disaster,

Despite the snow of the past two weeks the cold spell in terms of synoptics and coldness were very modest and the UK was lucky in having short waves move across at exactly the right latitude, things could easily have turned out far less interesting.

This Winter feels like one of wasted opportunity with the big SSW that had only modest effects (if any) in Western Europe and the very annoying habbit of the Greenland High bugging us all summer then going walkabout in Winter, while the Azores High does the reverse

As for the trend over the next 10 days yes its colder but nothing really exciting and that ticking sound is getting louder,,,,tick,tock.....

Andy

[nick sussex]

UKMO T96hrs fax chart, colder conditions spreading south with several fronts, looks quite wintry:

[Mair Snaw]

UKMO T96hrs fax chart, colder conditions spreading south with several fronts, looks quite wintry:

That 528 line just IMBY will take that as a start to Feb. quick question from a newbie does being at 250m asl make a difference to the 528 dam line or is that for sea level?. sorry if thats a silly question.

Edited January 28, 2013 by bigsnow

[Long haul to mild]

18z looking more like the UKMO with that Channel Low feature now gone for Saturday. Would be surprised to see the ECM continue modelling it in the morning. Should be some wintry showers in that flow I would imagine.

[phil nw.]

UKMO T96hrs fax chart, colder conditions spreading south with several fronts, looks quite wintry:

Yes it looks quite dramatic on that surface chart Nick-a direct northerly straight from the Arctic.

I guess it will be a brief one this time but a short butsharp reminder of what we could get from this setup if it improves further.

[Dibdabbers]

That 528 line just IMBY will take that as a start to Feb.

Hi I'm new to this can you explain why that line is significant ...thankyou :-)

[Geordiesnow]

UKMO T96hrs fax chart, colder conditions spreading south with several fronts, looks quite wintry:

Looks quite wet rather than wintry to me Nick!

Does not look like at this stage any Northerly is going to sustain for long enough for there to be much in the way of sunshine and snow showers unfortunately but a colder blip for the end of the week is looking more and more likely though.

[nick sussex]

Troughs shown in the flow, could be some snow overnight and further snow showers for the east and se in a strong n/ne flow.

[Grimsby Snow Lover]

Hi I'm new to this can you explain why that line is significant ...thankyou :-)

The 528 dam line is one of the factors needed if you are wanting showers to fall as snow. Hope this helps.

[phil nw.]

Hi I'm new to this can you explain why that line is significant ...thankyou :-)

Hi and welcome to the forum Dibdabbers.

This measurement is often used as one of the factors needed for snowfall although there are other things to take into account.

For a full explanation of Dam-lines here`s the link to our NW Guide.

I hope this helps.

[Long haul to mild]

Troughs shown in the flow, could be some snow overnight and further snow showers for the east and se in a strong n/ne flow.

That's a set up we've not really seen this winter so far. There's been a lot of frontal snow but very little convective activity. Could be an interesting little period over the weekend!

[Mair Snaw]

Hi I'm new to this can you explain why that line is significant ...thankyou :-)

new to this too but from what i understand its to do with the temp of the layer of air, 528 or less normally brings snow to the UK, guys if im wrong please explain.