Model Output Discussions 18z 31/01/2016

[snowray]

They are probably looking at strength of PPN, Evap cooling, that sort of thing. Many times a marginal snow event is preceded by light PPn in the form of drizzle and then it turns to snow as the heavier stuff arrives. 

[The Enforcer]

10 minutes ago, Ed Stone said:

And your super-accurate forecast is?

Now there's a gauntlet being thrown down. With the precipitation band in that position, this would be a more likely position for the snowfall at that time around the northern and eastern flanks. I expect the precipitation would be aligned differently in any event.

Edited February 10, 2016 by The Enforcer

[Nick F]

This model watching for any potential for elusive lowland snow for those of us in southern climes of the UK as we near the end of  this winter is proving to test the patience of saints. First we were teased with snow on Friday, this was put back to Saturday - now this potential has faded to a damp squib. Still hope for those in more central and northern areas for some lowland snow, albeit marginal, Saturday through into Sunday, as the rain pushes into colder air trying to spread SW.

Still enough time, though, for the low to track further south and cold air to filter further south on Saturday than currently progged and so moving the marginal rain to snow risk further south. Then some sleet and snow showers for the NE Sunday and Monday the next snow potential.

GFS continuing to hint at a disrupting Atlantic trough and frontal system a week away moving in to the cold stagnating  airmass  - which it shows bringing a widespread marginal snow event ... but is it another carrot at the end of the stick? Maybe several bites of the cherry later and we are finally rewarded, but there is the risk that the trough pushing down from the NW doesn't disrupt and remains intact - like the 00z ECM. So all eyes on ECM to see whether or not the trough disrupts.

My 4-year-old-son keeps asking me when it will snow enough this winter to play in, spurred on again by the snow he saw on TV in New Hampshire, but I keep telling him, to his dismay, maybe not this winter. 

Edited February 10, 2016 by Nick F

[SMU]

Evening all -

well the continued backtrack in the models ( mainly the GFS ) so far has gathered some momentum today with both the 00z & 12z GFS slowly correcting west as the model begins to 'see' the not so zonal train continue to be derailed

remember just 2 days ago the GFS & ECM punched the atlantic through blasting the cold away east - now as some of us have commented the energy dropping SE has been favoured

here for comparison is the 240 chart 2 days ago & then todays 00z & 12z 192 charts-

240

if you look cafefully the block is wayyyyy east towards russia

Now just 48 hours later the block is signalled to be over scandi

 

You will also note the 12z is further amplified to the 00z

what does it all mean - well we are at the point now where orginally a deep fast area of SW winds would sweep across the UK at around day 8/9 with a big mild wedge & no snow

however now that area of PPn is coming in at a sharper angle & sliding SSE with a small wedge of mild air in the SW part- allowing for snow over a swathe of the UK- its literally moved that way in 12 hours-

in terms of future runs - with this high pressure over scandi just being 'seen' late in the day then theres a high likleyhood that as we reach 144 over the next 48 hours then the high could be even stronger modelled & the CAA over europe could well be deeper & colder with the net result meaning colder for longer over the UK with more snow

it may also save us from the Mildest Winter on record....

we also have the messy siders to contend with over the weekend first!

lets see how the models develop over the next 24 hours-

this scenario of a scandi high suddenly being robust & lows dropping in from the NW has happened in recent years - im just trying to recall when it did !

S

 

[snowray]

ECM looking very good at T96, more of an Easterly there and the colder air just North of London.

Do I see an Icelandic High?

Edited February 10, 2016 by snowray

[Frosty.]

WOW just catching up and the Gfs 12z shows a nice snow event mid next week and most crucially it stays cold next week with widespread frosts...hopefully the cold will become entrenched with no return to milder Atlantic westerlies at all next week!

Edited February 10, 2016 by Karl.

[karlos1983]

Excuse my ignorance but what is CAA?

cheers

karl

Edited February 10, 2016 by karlos1983

[TomDav]

Just now, karlos1983 said:

Excuse my ignorance but what is CAA?

cheers

karl

Cold Air Advection i think

[karlos1983]

1 minute ago, TomDav said:

Cold Air Advection i think

D'oh course it is 

[Methuselah]

2 minutes ago, karlos1983 said:

D'oh course it is 

I've always thought that CAA is the Civil Aviation Authority...

[nick sussex]

The ECM not interested in sharpening that trough up. In this sort of set up you'd expect it to be the other way round with the GFS not interested.

 

[weirpig]

The uppers do seem colder on the ecm if only slightly on the weekend.  It may make a difference then again.

[Richard Lake]

'CAA'

 

Or perhaps an extra big department store that used to be in the UK.

Edited February 10, 2016 by djrikki

[mulzy]

JMA has a decent attempt at trough disruption over the UK

Usual caveats apply for a day 7 chart.

[Mucka]

Another ECM fail?

 

JMA shows the way.

Edited February 10, 2016 by Mucka

[Methuselah]

Never fear, the NAVGEM is here!

[I remember Atlantic 252]

2 minutes ago, Ed Stone said:

Never fear, the NAVGEM is here!

dosen't even bring in the Atlantic, for most of us 

[nick sussex]

I'm not sure the ECM is the end of the story here re that sharpening trough.

There is the possibility of a major storm for the ne USA and this is expected to form as a shortwave amplifies. The ECM is very flat over the USA between T144 and T168hrs and it looks like a non-starter between those timeframes.

The UKMO/GFS look more inline in terms of the expected pattern over the USA. Whilst the former isn't as good as the GFS it could still sharpen up the trough as this responds to the more amplified upstream set up.

[Frosty.]

Nice conclusion to the Ecm 12z

[Duane S.]

Very good 12z suite, if not in its absolute state, in relation to the zonal bulldozer that was being spouted only a few days ago.

Trough disruption (and the effects of) is far far from being resolved. I get the feeling we haven't seen the end of the corrections west as the charts roll out towards the weekend. I wouldn't be shocked to see a less deep system emerge and it slipping SE'wards to our SW and through Brittany, all but missing the bulk of the UK. Not a bad outcome as it would likely help lock in the cold for longer ( and of course bring the SW areas into play regards a snow event)

Edited February 10, 2016 by s4lancia

[joggs]

I think the Ecm will be the outlook for nxt wk due to looking like the mo outlook sounds.Too many promises this winter from all the models at most of the time and the mo have been very good imo.You might as well read the mo updates before coming in here if it's cold and snow your after.Saves the frustration lol.

Edited February 10, 2016 by joggs

[nick sussex]

1 minute ago, joggs said:

I think the Ecm will be the outlook for nxt wk due to looking like the mo outlook sounds.Too many promises this winter from all the models at most of the time and the mo have been very good imo.You might as well read the mo updates before coming in here if it's cold and snow your after.Saves the frustration lol.

The UKMO outlook suggested the chance of some snow as fronts approached from the Atlantic, transient in nature but that could only happen if the troughing to the nw sharpens up. The ECM has already mixed out the cold ahead of that trough. NCEP don't like tonights ECM operational run for the ne USA so I wouldn't assume that's its going to verify. Its already had one epic fail this week and that was within T72hrs. We'll have to wait for the morning where hopefully we can get some agreement upstream.

[Long haul to mild]

Someone pop out to Staples and get a trough sharpener for the ECM! Apparently the Bolivian model* has a trough so sharp its mum has warned it that it will cut itself one day.......

Seriously though, these charts have the sneaky hint of improvements in them and the GFS, which is usually first to plough in with a flat pattern is really picking up the baton for next week. These heights to the NE can be very hard to shift and it wouldn't surprise me at all to see some very interesting cold charts over the next few days.

We deserve some snow just for Nick Sussex's sake if nothing else; his quest for a countrywide event is tireless and  he won't even get to experience it if it does arrive! 

 

*may not exist 

[Frosty.]

3 minutes ago, joggs said:

I think the Ecm will be the outlook for nxt wk due to looking like the mo outlook sounds.Too many promises this winter from all the models at most of the time and the mo have been very good imo.You might as well read the mo updates before coming in here if it's cold and snow your after.Saves the frustration lol.

Next week is nowhere near resolved yet so let's just be happy, well the coldies at least..because a colder spell, as rare as hens teeth this winter, is coming and as we have seen from the gfs, the Atlantic might not punch through next week. In the meantime, some of us will see snow falling and hopefully accumulating, Sun / Mon look particularly cold.

[nick sussex]

11 minutes ago, Long haul to mild said:

Someone pop out to Staples and get a trough sharpener for the ECM! Apparently the Bolivian model* has a trough so sharp its mum has warned it that it will cut itself one day.......

Seriously though, these charts have the sneaky hint of improvements in them and the GFS, which is usually first to plough in with a flat pattern is really picking up the baton for next week. These heights to the NE can be very hard to shift and it wouldn't surprise me at all to see some very interesting cold charts over the next few days.

We deserve some snow just for Nick Sussex's sake if nothing else; his quest for a countrywide event is tireless and  he won't even get to experience it if it does arrive!

 

*may not exist

Lol! Yes its getting on my nerves. Its shocking that the UK at its latitude can't even muster one decent snow event in a whole winter. Not one with Carol Kirkwood stuck on the top of the N/York moors trying to big up some deep freeze with snow! I won't rest till the whole UK has seen a covering of snow, bizarre I suppose as I live down here in sw France but I'm psychically linked to the angst of UK cold and snow lovers! Seeing as I suffered so many crxp UK winters myself I understand your pain!

To use a film analogy I feel like that character out of Poltergeist, you know that short woman who goes into to get rid of the beast, but in this case I'm battling the PV beast, and her comments go into the light all are welcome can be changed to go into the snow all are welcome!

Only when the whole UK has seen snow can I mutter those immortal words "this house is clean" or in this case " the whole UK has had snow" and then shuffle my way out and back to my normal spring hibernation.

Poltergeist is one of my all time favourite films, apologies for derailing this thread with yet another of my film analogies!

Edited February 10, 2016 by nick sussex