Model output discussion - cold spell approaching?

[snowangel32]

29 minutes ago, Battleground Snow said:

Wow that is a very big shift, I'd expect the warning area to move south later this morning.

I've attached arome, also a shift

 

Going by that chart freezing rain could be a serious issue. But I expect by tomorrow it will again be even further South London area could be in the firing line if it continues the same trend South and West.

[KTtom]

Blimey!!

Terrible UKMO chart for the UK!

One of the main differences this morning is the low exiting Canada is more of a rounded low which doesnt provide the much needed WAA up the western side of Greenland.

 

 

 

Edited January 13, 2021 by KTtom

[Radiating Dendrite]

10 minutes ago, KTtom said:

Blimey!!

Terrible UKMO chart for the UK!

One of the main differences this morning is the low exiting Canada is more of a rounded low which doesnt provide the much needed WAA up the western side of Greenland.

 

 

 

Yes, not great.

Starting to think it will just never happen now. Everything gets watered-down in semi-reliable. Does make you question why the ECM and GFS go beyond 144 as they're never on the money. Let's hope it is just a blip

Edited January 13, 2021 by Radiating Dendrite

[Daniel]

Ecm just started. 

[Severe Siberian icy blast]

A wobble of sorts but certainly notning to start calling time on a spell that's not happened yet, the models have picked up on the hights to the south, and weakened the northerly blocking somewhat, however it doesn't mean too much on its own as its only one run, we have enough experience in this winter alone to understand the volatility of the models particularly when comparing each run with the previous one, 

The 0z over the last month has constantly gave us a wobble, with the runs slowly becoming more graceful as the day goes on, whether this is a data issue im not sure but the 0z do seem to of developed this theme

But it's best to compare like for like rather than comparing 18z/0z for example. 

18z quiet oftern give us the most prolific run of the day, so comparing 18/0z is pointless. 

Why this happens I haven't got the answers but it's certainly something iv noticed this winter in particularly. 

Let's just give it at least 24 hours to understand if it's something we need to accept, or not, as I hope the case may be.... 

And re tomorrow snowfall, it appears my ideas of a continued shift west has occurred which was almost a given, taking into consideration the classic situation of cold air to the east, under a strengthening high pressure. 

This along with the fact the jet stream having zero power to push the fronts through, leaves the lows meandering about like a sheep without a shepared grinding to a holt l, with a wave developing along the front holding it back, and increasing ppn levels as we go through tomorrow afternoon/evening. 

So certainly areas in the midlands I would put under the fireing line for snow, how much all depends on intensity, into the afternoon and more particularly the evening is the best chance for areas further south on low ground

Keep the faith

Edited January 13, 2021 by Severe Siberian icy blast

[NewEra21]

5 minutes ago, KTtom said:

Blimey!!

Terrible UKMO chart for the UK!

 

 

 

Those heights that were just over Spain/France on most models a few days ago are now just easing their way into Europe. Horrible, horrible chart!

[bluearmy]

 These cpc charts are decent illustrations that the trough axis is a little too ne/sw (improves a little from day 8 to day 11)

more importantly (and related), the angle of flow of the heights to our south needs to be more se (the arrows show it isn’t) which will keep the Atlantic air at bay. to anyone with a concern that they may end up too far north to benefit from the runners, don’t be. If you are under a cold slack trough then you will get occasional snowfall and it won’t melt. It’s best for the upper trough to clear the south coast into n France.  We may then miss the odd runner completely but it ensures that the whole country stays in the proper cold. 
 

I note the overnight runs have done nothing to alleviate the concerns from the below charts and if anything, they lessen the strength of the wedge/ridge over greeny 
 

  

[joggs]

1 hour ago, Battleground Snow said:

Difference v last night is stark on the GFS

Massive west based -NAO. If we were 2k miles further nw it would be great.

Sinking feeling ..........again 

If this is the trend, most will end up with rain. Not good at all from a coldie pov. If it can go wrong for us, it generally does.

[Mucka]

ECM 96h the low is a fair bit further NE than yesterdays 00z which seems to the morning trend but it better than GFS and while similar to UKMO upstream it is better downstream

ECM, GFS. UKMO

Edited January 13, 2021 by Mucka

[Mucka]

ECM 120 looks good, best of the morning anyway and we get the extra WAA NW from E flank of closed low to strengthen the ridge

Edited January 13, 2021 by Mucka

[BARRY]

4 minutes ago, Mucka said:

ECM 96h the low is a fair bit further NE than yesterdays 00z which seems to the morning trend but it better than GFS and while similar to UKMO upstream it is better downstream

ECM, GFS. UKMO

Is this another model climb down, happens most winters

[Battleground Snow]

1 minute ago, Mucka said:

ECM 120 looks good, best of the morning anyway and we get the extra WAA from Iberia to strengthen the ridge

Very much like the gem, but it's weaker than the 12z still, the gem wasn't great by the end of its run, let's see if ECM turns out different.

[The Beast From The East]

2 minutes ago, Mucka said:

ECM 96h the low is a fair bit further NE than yesterdays 00z which seems to the morning trend but it better than GFS and while similar to UKMO upstream it is better downstteam

Is this the Wobble we always hear about before a cold spell is due to start or is it the start of the charts watering down the cold spell? Usually it's always the back track sadly  but let's see what the models show us once they've had there breakfast ?

[bluearmy]

2 minutes ago, Mucka said:

ECM 120 looks good, best of the morning anyway and we get the extra WAA NW from E flank of closed low to strengthen the ridge

If this op manages to still deliver a wintry run countrywide from that position then many should chill out a bit  ......

 

[Ali1977]

Not sure 144 is going the right way!! 

[Mucka]

144 the best of a bad bunch

Certainly a long way from yesterdays output.

Let's hope this is as low as we go. It is really all about that second phasing low now. We just need it further SW and to stay closed while the ridge strengthens and the Scandi trough has time to draw in the cold.

Edited January 13, 2021 by Mucka

[Battleground Snow]

Thursdays snow line on ECM

 

[bluearmy]

Closest model to ec at day 6 is the para 

[Mucka]

2 minutes ago, bluearmy said:

Closest model to ec at day 6 is the para 

Yes very close.

It is amazing how that low has suddenly been turbo charged to burst through and give us a more worrisome W based -NAO

Still time for it to change I guess but all the output has pushed it further NW rather than SW

Edited January 13, 2021 by Mucka

[That ECM]

Not done but not great as a trend. Let’s see what the 12z look like. See you all this evening, mods are going to have a busy day when everyone wakes up

Edited January 13, 2021 by That ECM

[Battleground Snow]

4 minutes ago, bluearmy said:

Closest model to ec at day 6 is the para 

Para v gem v ECM at 168

 

[bluearmy]

1 minute ago, Mucka said:

Yes very close.

It is amazing how that low has suddenly been turbo charged to burst through and give us a more worrisome W based -NAO

Still time for it to change I guess but all the output has pushed it further NW rather than SW

By day 7 it’s the gfs op!

incidentally, assuming ssw related but the lows struggling to  get past the meridian out to day 7 to our north which means we struggle to clear the upper trough to our east and advent the cold across nw Europe. Watch the feature at day 6 and 7 n of Scotland ....it moves sw. 

[Radiating Dendrite]

1 minute ago, bluearmy said:

By day 7 it’s the gfs op!

incidentally, assuming ssw related but the lows struggling to  get past the meridian out to day 7 to our north which means we struggle to clear the upper trough to our east and advent the cold across nw Europe. Watch the feature at day 6 and 7 n of Scotland ....it moves sw. 

So the lack of a stronger Atlantic jet is killing our cold spell and leaving us in a west based NAO no man's land?

You literally couldn't make this stuff up. We are cursed here in the UK.

[ItNeverSnowsInWindsor]

Looks like the signal for a severe cold spell is diminishing by the day with fewer members going below -10c and more milder options appearing.

Edited January 13, 2021 by prolongedSnowLover

[Vikos]

Mild interludes are normal in cold winters prior cold spells. We are still in mid January with at least 6 weeks and more of pure winter time and chances. Don’t throw away your guns! Remember 2010 when models flipped in short range...