Model output discussion - 20th Feb onwards

[chris55]

So an interesting period of model watching coming up!

Going from the 00z ECM we can see that from 48 through to 120 the whole of the UK is bathed in some pretty cold air, although quite settled, this will result in some very cold nights for the main and some sunny but chilly days (we do have to take into account the strength of the sun at this stage in winter, which means chilly days and not ice days).

Beyond this we have to consider how that Biscay low (or energy in the vicinity) interacts with the colder air over the UK and the high pressure over us, and to the north, but also what happens to the mild air being wrapped around to the south!

These details will not be sorted for a fair few runs yet i would suspect, however the ingredients are there for some snowfall to parts of the UK, and the southern half of the country looks like a good place to be IMO.

Beyond this Ians posts are suggesting that the Mets various model suits are pointing towards a continuation of the colder conditions.

Certainly lots going and past 120 I'd say the ops are open to some changes whatever they are showing.

[IDO]

Again the 12z shows the second diving low next weekend go too far south and Spain/Portugal get some heavy persistent snow. The low is not as intense and that means the uppers are not warmed out as much. Not much use for us at the moment with all the action further south. D6:

So cool-cold with no frontal or snow from shortwaves. Maybe a trough or disturbance in the flow, but not a lot really. So dry mainly for 95% of the mainland.

 

[feb1991blizzard]

Just now, karyo said:

Those troughs coming down the Irish sea often pep up as we approach the event. In other words, the precipitation charts tend not to pick them up well.

For example, previous GFS runs had hardly any precipitation although the 0z UKMO had a trough coming down from the northwest at the same time.

Possibilities but just suspect the high will be a bit close, could get something I suppose.

[snowice]

Loads of lake effect snow on east coast of uk and Ireland-8 uppers here comes winter.Gfs has cold Easterlys of warm sea cold uppers =snow machine.

Edited February 21, 2016 by snowice

[chris55]

7 minutes ago, IDO said:

Again the 12z shows the second diving low next weekend go too far south and Spain/Portugal get some heavy persistent snow. The low is not as intense and that means the uppers are not warmed out as much. Not much use for us at the moment with all the action further south. D6:

So cool-cold with no frontal or snow from shortwaves. Maybe a trough or disturbance in the flow, but not a lot really. So dry mainly for 95% of the mainland.

 

Trying to pick out ppn at 144 is simply futile IDO.

Often once the cold air is in situ ppn events pop up at T48 or even less.

Its the broad-scale pattern we should be focusing on.

And as the flow is from the east dew points are looking pretty good, as well as the 850s!!  

DP

Edited February 21, 2016 by chris55

[Blake]

Thames/Kent streamer...?

Could be good from an IMBY perspective. Low further north on this run.

[Ice Day]

UKMO at 144hrs looks good, uppers are of course unknown but should be cold enough!?

Edited February 21, 2016 by Ice Day

[Banbury]

UK is ok at 144

[chris55]

12 minutes ago, Banbury said:

UK is ok at 144

At face value that chart is immense!!

Looking very nice in general at the moment for a late winter shock eh!

Edited February 21, 2016 by chris55

[Gowon]

There's always shortwaves that hang around to the NW that stops proper ridging to the north.. The ukmo makes less of it, but you can see on the gfs it just hangs around.

 

 

[Banbury]

Anyone know why you cant get the uppers off the UKMO charts? Just wondering why they leave them off

[IDO]

Just now, chris55 said:

Trying to pick out ppn at 144 is simply futile IDO.

Often once the cold air is in situ ppn events pop up at T48 or even less.

Its the broad-scale pattern we should be focusing on.

And as the flow is from the east dew points are looking pretty good, as well as the 850s!!  

Yes I know. Just looking for something more substantial. That LP had UK on it a few runs ago, now a pasting for the Alps and N. Spain.

As you say the disturbances pop up at T-24 so no point worrying about those yet though they by nature will be hit and miss.

Anyway not even sure that we have next weekend's synoptic resolved yet. GEM is totally different to GFS by D5 and UKMO also a variation on a theme:

GEM at D5:

[SMU]

Afternoon-

Lets not underestimate the 12Z UKMO

One of the best runs of the winter, more so because there is deep cold ( -8c) at T72 

At 144 the flow allignment means minimal mixing of Mild uppers from the ESE & another cold pool dropping into scandi for continuation of cold thereafter...

As said - the best run of the year because the cold is not +6 days away-

also plenty of snow opportunities - even in the far SW !

S

[Long haul to mild]

2 minutes ago, IDO said:

Yes I know. Just looking for something more substantial. That LP had UK on it a few runs ago, now a pasting for the Alps and N. Spain.

As you say the disturbances pop up at T-24 so no point worrying about those yet though they by nature will be hit and miss.

Anyway not even sure that we have next weekend's synoptic resolved yet. GEM is totally different to GFS by D5 and UKMO also a variation on a theme:

GEM at D5:

I've long since given up on the GEM, I find it appalling generally. Every now and again it is correct, but I think it's more because of the "even a stopped clock tells the right time twice a day" maxim than anything else......

[shaky]

Just now, Steve Murr said:

Afternoon-

Lets not underestimate the 12Z UKMO

One of the best runs of the winter, more so because there is deep cold ( -8c) at T72 

At 144 the flow allignment means minimal mixing of Mild uppers from the ESE & another cold pool dropping into scandi for continuation of cold thereafter...

As said - the best run of the year because the cold is not +6 days away-

also plenty of snow opportunities - even in the far SW !

S

Exactly!!if people think gfs 12z was good well the ukmo looks a lot better and a reinforcement of cold coming in from the north east at 144 hours!!

[IDO]

2 minutes ago, Long haul to mild said:

I've long since given up on the GEM, I find it appalling generally. Every now and again it is correct, but I think it's more because of the "even a stopped clock tells the right time twice a day" maxim than anything else......

Up to D5 (as far as I will go as by D10 it is awful) it regularly beats GFS. Current verification they are close at T120:

 

Edited February 21, 2016 by IDO

[chris55]

10 minutes ago, IDO said:

Yes I know. Just looking for something more substantial. That LP had UK on it a few runs ago, now a pasting for the Alps and N. Spain.

As you say the disturbances pop up at T-24 so no point worrying about those yet though they by nature will be hit and miss.

Anyway not even sure that we have next weekend's synoptic resolved yet. GEM is totally different to GFS by D5 and UKMO also a variation on a theme:

GEM at D5:

Id say the best suite of models comes from the Met office, sadly we don't have access to them, however Ian has intimated a continuation of the cold until well into March. For now that's enough for me at least to take the ops with a pinch of salt as we move beyond days 5-6.   

Edited February 21, 2016 by chris55

[Summer Sun]

7 minutes ago, Banbury said:

Anyone know why you cant get the uppers off the UKMO charts? Just wondering why they leave them off

Could be licensing reasons or maybe the cost? I'm sure Fergie or someone else will be able to confirm

[Long haul to mild]

Just now, IDO said:

Up to D5 (as far as I will go as by D10 it is awful) it regularly beats GFS. Current verification they are close at T120:

 

Interesting. Admittedly I tend to only look at it in the medium range and always find it bad at spotting trends, be they mild or cold.

[winterof79]

14 minutes ago, snowice said:

Loads of lake effect snow on east coast of uk and Ireland-8 uppers here comes winter.Gfs has cold Easterlys of warm sea cold uppers =snow machine.

It happened a few years ago in a slack set up.Streamers off the Irish Sea dumped 9" of snow to here and further north Pately Bridge North York's.-8 air is unstable.

[A.J]

3 minutes ago, Steve Murr said:

Afternoon-

Lets not underestimate the 12Z UKMO

One of the best runs of the winter, more so because there is deep cold ( -8c) at T72 

At 144 the flow allignment means minimal mixing of Mild uppers from the ESE & another cold pool dropping into scandi for continuation of cold thereafter...

As said - the best run of the year because the cold is not +6 days away-

also plenty of snow opportunities - even in the far SW !

S

you've just made my day with that last statement Mr Murr, thankyou! 

At face value the GFS does look pretty dry in the out until FI (although just dry is a relief for everyone who's been affected by flooding) but one thing I've learnt is that small disturbances rarely show up on the GFS (I think?) ...and as many learned people have posted over the years, get the cold in place, and the snow will follow......here's to a cracking wintry spell for everyone 

[feb1991blizzard]

1 minute ago, Summer Sun said:

Could be licensing reasons or maybe the cost? I'm sure Fergie or someone else will be able to confirm

I think (if someone can confirm) You used to be able to get the uppers but only up until 72 on meteociel, now ironically you cant get anything up until 72 but you can get H5 for rest of the run!!

[TomDav]

4 minutes ago, IDO said:

Up to D5 (as far as I will go as by D10 it is awful) it regularly beats GFS. Current verification they are close at T120:

 

Although those skill scores are for the entire northern hemisphere I think so less representative

[Frosty.]

Awesome ukmo 12z, especially the T+144 chart which is an absolute peach with height rises to the NW and a scandi trough nicely aligned and low pressure to the south with the uk locked into an Arctic airflow with lots of snow potential...superb!

[Hull snow]

Snow wise how many days away is this potencial snow machine great chats long may it continue