Model output discussion - Winter has arrived

[West is Best]

And by the way, there's quite a storm brewing for tomorrow night in the far west and south-west:

 

 

[sheikhy]

22 minutes ago, Tim Bland said:

Who know which one is accurate Not too much in it now though. Here’s the ECM ... 

You got the charts for 12pm and 3pm mate? Also any snow depth charts?

Edited December 3, 2020 by sheikhy

[Tim Bland]

17 minutes ago, sheikhy said:

You got the charts for 12pm and 3pm mate? Also any snow depth charts?

Have a look on this site. If you use it on your phone it works very well, really simple drop down menu for models 

WXCHARTS

WXCHARTS.COM

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A new weather forecast model data viewer for Europe and North America. Clickable forecast and ensemble plots...

 

[nick sussex]

The morning outputs in good agreement which makes a change !

One change is yet another troublesome shortwave which hangs over the UK at day 6 .

The phasing of that with the approaching low from the west complicates whether there could be some snow off the frontal band . The phasing effects the approach of that low so the flow into the UK is impacted .

The key in these situations is to get a feed of drier colder air undercutting the precipitation .

The situation was marginal anyway because at this point there’s not the normal amount of cold to the east se to draw on .

The ECM does however develop a slightly colder pool to the east se . At the moment it looks mainly rain from that band but more uncertain towards the se which could hang onto a sufficient flow off the continent . Again though exactly how much cold would be there to draw on at this stage is still uncertain .

The models are overall more progressive this morning so any snow would likely be transient unless that is they start to pull back from that and disrupt more energy se’wards.

[carinthian]

Morning all, ECM run produces some widespread frontal snowfall for much of the British Isles towards the back end of next week with some impressive accumulations over upland Britain, especially the north, I have just asked our portal service forecasters their view on this chart and the UKMO/ ECM run. Their view is by the middle of next week, low pressure will be active over Northern Italy with the westerly jet  still being deflected against the most dominant feature still being West Russia  High. Obviously forecasts much beyond 144t will be very much open to change. However, the scenario of Atlantic lows/troughs heading  towards Western Europe will coming up against an increasing block of colder air mass as the days progress and may produce the snowfall as shown on the chart below. The million dollar question is , will the Russian high start to move and flex its muscles or the Atlantic milder lateral flow push trough. Very interesting , old school winter battle on the cards. They think 60/40 in favour of an extended cold outlook. 

Edited December 3, 2020 by carinthian

[nick sussex]

2 minutes ago, carinthian said:

Morning all, ECM run produces some widespread frontal snowfall for much of the British Isles towards the back end of next week with some impressive accumulations over upland Britain, especially the north, I have just asked our portal service forecasters their view on this chart and the UKMO/ ECM run. Their view is by the middle of next week, low pressure will be active over Northern Italy with the westerly jet  still being deflected against the most dominant feature still being West Russia  High. Obviously forecasts much beyond 144t will be very much open to change. However, the scenario of Atlantic lows/troughs heading  towards Western Europe will coming up against an increasing block of colder air mass as the days progress and may produce the snowfall as shown on the chart below. The million dollar question is , will the Russian high start to move and flex its muscles or the Atlantic milder lateral flow push trough. Very interesting , old school winter battle on the cards. They think 60/40 in favour of an extended cold outlook. 

That’s interesting so the ECM at least factors in some snow off that frontal band especially for higher ground .  Much depends though on how the models deal with the shortwave over the UK . If it’s going to remain it needs to be as shallow as possible . That really complicates an already complicated scenario ! 

[sheikhy]

11 minutes ago, carinthian said:

Morning all, ECM run produces some widespread frontal snowfall for much of the British Isles towards the back end of next week with some impressive accumulations over upland Britain, especially the north, I have just asked our portal service forecasters their view on this chart and the UKMO/ ECM run. Their view is by the middle of next week, low pressure will be active over Northern Italy with the westerly jet  still being deflected against the most dominant feature still being West Russia  High. Obviously forecasts much beyond 144t will be very much open to change. However, the scenario of Atlantic lows/troughs heading  towards Western Europe will coming up against an increasing block of colder air mass as the days progress and may produce the snowfall as shown on the chart below. The million dollar question is , will the Russian high start to move and flex its muscles or the Atlantic milder lateral flow push trough. Very interesting , old school winter battle on the cards. They think 60/40 in favour of an extended cold outlook. 

Thought that was tomorrow mornings for a second!!was thinkinh how widespread is that

[SMU]

ICON 06z a swing west towards the ECM with the PPN getting to London now - 

 

[sheikhy]

6 minutes ago, Steve Murr said:

ICON 06z a swing west towards the ECM with the PPN getting to London now - 

 

Steve this looks like one of those radar watchin moments down to the last minute!!accumulations are further slightly further east this morning on ecm!!want to be excited about it but kinda hard in fear of being let down

[johnholmes]

Thur 3 Dec and another look at the latest

Ec-gfs and both have dropped the ridging/+ve height link from n Europe/Russia across Greenland and to n America; the 500 flow on both is slightly n of w into the very marked trough uk into Europe and the med.

Noaa retains a degree of ridging/+ve heights and as it has shown for several days a marked trough with –ve heights in it. The 8-14 looks, to some extent, similar to the straighter flow of the other 2. Anther point to note is the trough-ridge position in the far west. This is now further west than when the models first signalled a more meridional flow.

So we are, I think, seeing the blocking pattern starting to break down. It remains to be seen if this is a blip or something more substanti

links, as usual are below

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.ncep.noaa.gov//favicon.ico Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

[Anthony Burden]

Hints from charts this morning that the cold spell from 8 days out might return to more

average temperatures,not certain by any means.In the mean time snow possible in several 

parts of the U.K. and very wintery.

[northwestsnow]

EC cluster 1 and 4 bring a block to the NE next week...

[North East Blizzard]

6 minutes ago, northwestsnow said:

EC cluster 1 and 4 bring a block to the NE next week...

Yeah Matt Hugo just tweeted similar, more members going for northerly blocking than a return to an Atlantic onslaught. Interesting. 

[bluearmy]

5 minutes ago, northwestsnow said:

EC cluster 1 and 4 bring a block to the NE next week...

My take is that we will see more blocking towards svaalbard through week 2

[bluearmy]

8 minutes ago, North East Blizzard said:

Yeah Matt Hugo just tweeted similar, more members going for northerly blocking than a return to an Atlantic onslaught. Interesting. 

We are losing euro low anoms though ....

latest gfsp is a good illustration of what we may see in the 8/12 day period as the lw  trough axis gets a little too far north 

Edited December 3, 2020 by bluearmy

[Tim Bland]

GEFS not really interested in anything cold long term

[northwestsnow]

8 minutes ago, bluearmy said:

We are losing euro low anoms though ....

Sounds like that signal is maintained.

Drat.

[SMU]

12 minutes ago, bluearmy said:

My take is that we will see more blocking towards svaalbard through week 2

Some of the runs in try trying to bring a trough south past that region in the mix!

[TSNWK]

I'm trying to figure out the potential outcome is heights did rise over Svaalbard but we lose the low heights to our south? would it just be like nothingness - calm, chilly?  

[northwestsnow]

12 minutes ago, bluearmy said:

We are losing euro low anoms though ....

latest gfsp is a good illustration of what we may see in the 8/12 day period as the lw  trough axis gets a little too far north 

Which ties in with us losing the Euro low...

 

[northwestsnow]

Just now, TSNWK said:

I'm trying to figure out the potential outcome is heights did rise over Svaalbard but we lose the low heights to our south? would it just be like nothingness - calm, chilly?  

Smart money would be a swift return to garbage +NAO...

EC46 will be interesting later.

[mushymanrob]

12 hours ago, Steve Murr said:

Tell me how 5cm of snowcover adds up to rain & sleet? 

?..... who is getting that and when steve? not being funny or owt but most of us wont even see anything white falling let alone settle on warmer wet ground, or at best settle for long.

[snowking]

In the shorter term, taking a look at our little wave feature which brings the possibility of something wintry across a swathe of England tomorrow from the point of view of a selection of high resolution modelling available to us:

The general trend has been to push this feature significantly further East - the holdouts really continue to be Harmonie and the ECMWF.

Of course we all know in reality that with such a complex feature it will be all about radar watching in the morning. Without some substantial intensity to the precipitation I'm still struggling to see much in the way of lowland snow - so all eyes to the radar.

[northwestsnow]

6z looking a little more appealing ?

We are desperate for some retrogression in the Atlantic.

[Methuselah]

1 minute ago, northwestsnow said:

6z looking a little more appealing ?

We are desperate for some retrogression in the Atlantic.

Indeed... Freezing-fog patch incoming!