Model output discussion - 21st Jan Onwards

[Man With Beard]

Temperatures definitely on the way down for the first week of Feb - quite a surprise for me after seeing the ensembles a few days ago. Whether cold enough for lasting snow or not, looking encouraging for northern areas but the south still likely to miss it (though at least 'in the game' now). The 10C+ days are over after D5 on ECM, and GEFS 850s for London has a nice cluster at -6C for at least 48 hours next week.

[Frosty.]

8 minutes ago, Jason M said:

 

I thought Frosty's summary looked perfectly reasonable. 

 

 

Cheers Jason ....and Paul

Edited January 28, 2016 by Frosty.

[jvenge]

3 minutes ago, Frosty. said:

I suppose that was aimed at me? I am not visually challenged but I can't see anything wintry in the south where most members on here are from with max temps in the 5 / 8 celsius range! 

Heh! Difficult to see anything south of the midlands actually. Rain and maybe sleet. Looks like only the hills to me, even in the north. 

[booferking]

9 minutes ago, Paul said:

Frosty is making a reasonable point - if anyone is expecting lying snow away from the higher ground of northern Britain (perhaps excluding lower parts of northern Scotland) during the weekend, then they're going to be disappointed. This weekend will bring some wintriness, but we're talking sleet, wet snow, hail etc at lower levels from the midlands northward, so don't be dusting the sledges off unless you plan to climb a hill! 

 

6 minutes ago, Frosty. said:

I suppose that was aimed at me? I am not visually challenged but I can't see anything wintry in the south where most members on here are from with max temps in the 5 / 8 celsius range! 

Why does everybody think this isle starts from the midland south???? And why are clearly missing out the 3 key words used in the sentence???? most of us

[EastAnglian]

Frosty so did I seemed very reasonable to me although that type of representation with the hatching always confuses me what is wrong with good old purple for snow? 

2 minutes ago, Frosty. said:

Cheers Jason

 

[Paul]

3 minutes ago, booferking said:

 

Why does everybody think this isle starts from the midland south???? And why are clearly missing out the 3 key words used in the sentence???? most of us

But most of us don't live on the top of hills and mountains! Which is kind of the point I'm making - if you want lying snow, you need to be from the midlands north & high up..

[winterof79]

Calm down people. Here's a probability chart from the mild machine  more commonly known as the GFS

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=6&code=&mode=26&carte=3&proba=1

 

I do not live on the top of a hill nor a mountain and refer people to this diagram once more. It may not be settling snow but who cares after such a turgid start to winter

And this is the milder model output outcome so chins up.

Edited January 28, 2016 by winterof79

[Frosty.]

1 minute ago, Paul said:

But most of us don't live on the top of hills and mountains!

Absolutely Paul, thanks for your support

[nick sussex]

A disappointing ECM run this morning which although having a very similar NH pattern has less amplitude upstream and doesn't clear shortwave energy to the west.

As I mentioned last night you don't want any phasing with shortwave energy in the Atlantic because this stops a stronger ridge from developing to the nw.

As soon as this phasing happens you're left with a struggle as this pulls the upstream troughing further east and stops decent WAA to the east/ne to help develop a stronger ridge.

The knock on effect is the pattern is edged east and the cold advection reduced into the UK.

Regardless of its days 9 and 10 output there shouldn't be the assumption that this will verify when we've already seen negative changes within T144hrs.

Edited January 28, 2016 by nick sussex

[BarnetBlizzard]

15 minutes ago, booferking said:

Yea maybe for you rain!   but really can people in here not read maybe i need to highlight the 3 crucial words that people love to overlook.  most of us

 

Now when you look at that chart provided kindly by Rocheydub you can see over 3/4 of the country is seeing some way in form of snow

You take that GFS chart way too literally. It is by no mean accurate. If you want to look at precipitation type and amount in more detail then there are several good options on a site like Meteociel. 

[Paul]

Just to give some idea of heights with the decent snow risk (ie a better chance of lying snow). Looks like northern England - 200-400m, north Wales, 300-400m, Scotland 100-200m, and Northern Ireland 200-300m, 100-200 in places. 

 

[Frosty.]

7 minutes ago, nick sussex said:

A disappointing ECM run this morning

Not a bad end though Nick, very 2010  like

[Abyss]

30 minutes ago, Paul said:

Frosty is making a reasonable point - if anyone is expecting lying snow away from the higher ground of northern Britain (perhaps excluding lower parts of northern Scotland) during the weekend, then they're going to be disappointed. This weekend will bring some wintriness, but we're talking sleet, wet snow, hail etc at lower levels from the midlands northward, so don't be dusting the sledges off unless you plan to climb a hill! 

But it's not just Northern Scotland that will see lowland snow as you adamantly state. I'm sure certain areas of Northern Ireland and Southern Scotland won't have to climb a mountain to see some lying snow but rubbish for the South as usual. As per the met office warning " snowfall is possible to low levels at times, especially overnight." Whilst not snow galore lowland snow cannot be ruled out. Met office regional fc for NI and Strathcylde "Bitterly cold Saturday with sleet or snow showers and gales."

 

 

Edited January 28, 2016 by -Bomber-

[booferking]

11 minutes ago, Paul said:

But most of us don't live on the top of hills and mountains!

Okay i see were your coming from but them snow charts i always take with a pinch of salt, snow here last night cookstown 76 msl and in Derry sea level with the brief cold interlude we had.

 

 

[winterof79]

1 minute ago, -Bomber- said:

But it's not just Northern Scotland that will see lowland snow as you adamantly state. I'm sure certain areas of Northern Ireland and Southern Scotland won't have to climb a mountain to see some lying snow but rubbish for the South as usual. As per the met office warning " snowfall is possible to low levels at times, especially overnight." Whilst not snow galore lowland snow cannot be ruled out.

 

 

Here is euro4s take on early Saturday am

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2016/01/28/basis06/ukuk/prty/16013006_2806.gif

[booferking]

11 minutes ago, Paul said:

Just to give some idea of heights with the decent snow risk (ie a better chance of lying snow). Looks like northern England - 200-400m, north Wales, 300-400m, Scotland 100-200m, and Northern Ireland 200-300m, 100-200 in places. 

 

Okay i see were your coming from but them snow charts i always take with a pinch of salt, snow here last night cookstown 76 msl and in Derry sea level with the brief cold interlude we had.

[Eskimo]

The models are trending colder, with the opportunity for lowland snow increasingly likely as the days go on. Just be patient, for the sake of this great forum.

Edited January 28, 2016 by Polar Maritime

[nick sussex]

12 minutes ago, Frosty. said:

Not a bad end though Nick, very 2010  like

Unfortunately at day ten and given the backtrack already from the ECM then I wouldn't be confident of this verifying. If we can't even get the ECM to verify within T144hrs then  at T240hrs its expecting an awful lot for something else to not go wrong. As soon as the upstream troughing phases then you're already on a sticky wicket with no margin for error.

Show me last nights output again this evening and I might change my tune, however I'm not convinced at the moment.

Bear in mind the ECM only manages to get to day ten without going completely pearshaped because lobes of the PV are not thrown back westwards across Greenland.

 

Edited January 28, 2016 by nick sussex

[Singularity]

14 minutes ago, nick sussex said:

A disappointing ECM run this morning which although having a very similar NH pattern has less amplitude upstream and doesn't clear shortwave energy to the west.

As I mentioned last night you don't want any phasing with shortwave energy in the Atlantic because this stops a stronger ridge from developing to the nw.

As soon as this phasing happens you're left with a struggle as this pulls the upstream troughing further east and stops decent WAA to the east/ne to help develop a stronger ridge.

The knock on effect is the pattern is edged east and the cold advection reduced into the UK.

Regardless of its days 9 and 10 output there shouldn't be the assumption that this will verify when we've already seen negative changes within T144hrs.

Two sides to it I suppose; disappointment to see that low not behaving so favourably, but a degree of encouragement from the fact that the blocking theme driven by increased amplification from the Pacific still manages to establish.

Trouble is, the former is far more important with respect to whether the traditionally less snowy parts of the UK see anything of note within the more reliable range. Still some water to pass under the bridge though. UKMO seems to merge the shortwave pretty soon, yet the +144 chart suggests that the trough S of Greenland could exhibit a SE movement, perhaps with trough disruption as the Arctic High pushes into Greenland.

My conclusion is that the changes via the polar regions, initiating from a combination of a major ridge from the Pacific via Alaska and slight support from the displacement event in the stratosphere, is the dominant player for the overall trend over the next week or so, but any snow events in less climatologically favoured areas of the UK are a matter of small scale details  in the Atlantic.

In other words, the usual ordeal that we face whenever big changes are going on with the polar profile  

 

[Methuselah]

16 minutes ago, PerfectStorm said:

Some people clearly need another hobby, as to be disagreeing/arguing about whether places will get snow, even against the more seasoned posters here is really very sad.

The models are trending colder, with the opportunity for lowland snow increasingly likely as the days go on. Just be patient, for the sake of this great forum.

But, one's being a 'more seasoned poster' doesn't necessarily make one right, does it? Even us 'more seasoned posters' are capable of becoming a tad over-excited at times?

Edited January 28, 2016 by Ed Stone

[nick sussex]

Good post Singularity. I said the other day that my attitude to the outputs would be governed by whether they could produce non-marginal snow, frosts for several days and something more UK wide.

We don't have weeks to play with and chasing around a few hours of slush simply doesn't cut it IMO given the dire winter so far.

I'm happy to call a spade a spade. Last nights ECM was good and  had some scope for further improvements, todays outputs are generally the chasing around slush variety and therefore IMO are underwhelming.

My zero tolerance approach might not go down well as I might come across as being a bit of a Grinch but I'd like to see snow and cold deliver to the whole UK and especially areas that missed out on that  snow a few weeks back. Although even that was a pretty average affair.

Edited January 28, 2016 by nick sussex

[Rocheydub]

35 minutes ago, BarnetBlizzard said:

You take that GFS chart way too literally. It is by no mean accurate. If you want to look at precipitation type and amount in more detail then there are several good options on a site like Meteociel. 

To which I have also looked. HIRLAM also shows snow showers on Saturday across a large swathes of these islands. It will be marginal, I have no doubt, but you cannot rule it out! That would be foolish! 

[karlos1983]

For a second I thought I had missed something on this mornings model runs with the amount of new posts pinging off in the background, but then I started the painful process of reading err nothing.

To me we are no clearer on the path for next week. yesterday's 12z ECM was so jaw droppingly  good, that let's be honest, I think we all knew that the only way from there was going to be steps backwards, so still all to play for.

This weekend there will be snow in the North at elevation, but hey, it's Winter and thats kinda standard winter affair is it not? 

Don't understand why things become so personal in here, it is just the weather.........

 

 

[Frosty.]

18 minutes ago, nick sussex said:

Unfortunately at day ten and given the backtrack already from the ECM then I wouldn't be confident of this verifying. If we can't even get the ECM to verify within T144hrs then  at T240hrs its expecting an awful lot for something else to not go wrong. As soon as the upstream troughing phases then you're already on a sticky wicket with no margin for error.

Show me last nights output again this evening and I might change my tune, however I'm not convinced at the moment.

Bear in mind the ECM only manages to get to day ten without going completely pearshaped because lobes of the PV are not thrown back westwards across Greenland.

 

Lol Nick if you thought the ecm was poor, hope you didn't see the gfs 6z

[Paul]

29 minutes ago, -Bomber- said:

But it's not just Northern Scotland that will see lowland snow as you adamantly state. I'm sure certain areas of Northern Ireland and Southern Scotland won't have to climb a mountain to see some lying snow but rubbish for the South as usual. As per the met office warning " snowfall is possible to low levels at times, especially overnight." Whilst not snow galore lowland snow cannot be ruled out. Met office regional fc for NI and Strathcylde "Bitterly cold Saturday with sleet or snow showers and gales."

 

Not sure if you're trying to put words in my mouth or are just misunderstanding. but I'm talking actual lying snow. In heavier bursts, then lower levels may see snow, but it's likely to be wet, and not settle, or at the very least not settle any more than very temporarily.