Model Output Discussion - Christmas and New Year

[Allseasons-Si]

1 minute ago, Scott Ingham said:

The wrap around off the North sea gives Lincolnshire South Yorkshire and Derbyshire moderate to heavy snow from 6pm till the next morning. 

Good time with it being nighttime!

Yeah just looked at this...

then it heads down into SW England.

[SMU]

Just now, Kasim Awan said:

The difference this time is a slightly low ppn intensity requirements for snow - then about 40% now >65% of the precip will be snow Mon AM. The upshot of this is greater confidence in accumulation once the low track is resolved reflected in the lesser precip intensity requirements.

ECM Hi Res does seem good at resolving at ranges >T60. However if it was too far west then I would bank that it might be marginally too far north right now anyway. M4 south for me.

Yes - I would like the track a bit more east to cut off the onshore SE bend ( for me )

 

GFS now full on amplification towards the Euros at 144....

[ALL ABOARD]

Yes 144 much better... 

[Tim Bland]

Still seems bizarre that on models like GFS we get almost zero precip considering the low is slap bang over us

Edited December 25, 2020 by Tim Bland

[Kentspur]

14 minutes ago, Allseasons-si said:

Evening all

not been on all day(boy that was hard lol)as i spent time with the family as i promised them and it does do you good to get away for a time,remember that saying,...absence make the heart grow fonder,...glad to be back though

it took a while to read through here this evening and i see that the downgrade brigade is out in force as soon as they smell a whiff in the horizon but personally i don't see that at all looking at the latest charts and anomalies

i see no relaxation from a meridian flow on these...

cpc 6-10/8-14 day 500mb outlook

Climate Prediction Center - 6-10 Day 500mb Outlook

ORIGIN.CPC.NCEP.NOAA.GOV

EPS at day ten 500mb and 850's temp anomalies

 

EPS Model

WWW.TROPICALTIDBITS.COM

---

500mb Height Anomaly

NAO/AO still on the cobra neg slide esp the AO

and lastly,...i have just tried some mulled wine that someone got me as a gift...yuck

Fantastic anomalies there from EPS up to 5c colder than normal over most of the south and central England is surely cold enough for some snowy surprises if there's enough precip around❄

 

 

[Weathizard]

Simply sensational, Merry Christmas  

[dragan]

1 minute ago, Tim Bland said:

Still seems bizarre that on models like GFS we get almost zero precip considering the low is slap bang over us

i wonder if it’s  BDBM , so pressure is so low it won’t allow precip to form...

[Mike Poole]

Well one thing you can say with this pub run, is that the cold as is available is now in place.  Cracking run, T162:

Some margin for error now built in.  Let’s see where it goes.  

[Purga]

There'll be some happy folks in Hampshire

[Kasim Awan]

5 minutes ago, Steve Murr said:

Yes - I would like the track a bit more east to cut off the onshore SE bend ( for me )

 

GFS now full on amplification towards the Euros at 144....

Hopefully you'll get heavy enough ppn to erode that maritime layer.. Valid worry as a more northerly track would take the heavier stuff inland. The result could be ice pellets for some.

[iceman1991]

5 minutes ago, Tim Bland said:

Still seems bizarre that on models like GFS we get almost zero precip considering the low is slap bang over us

Yeah because y it oi have Covid vaccine 

[Allseasons-Si]

The gfs develops a feature/trough in thee flow over England at 162.

[kold weather]

Another cold run from the GFS again.

Also, reasonably snowy with several bands beyond the 28th. The ECM gas hinted at other bands recently as well so something to have a watching brief with I think.

[Ice Day]

Out to 180 and there's a cold pool growing in situ to our north east, turning into yet another cracker this run.  Love it!

   

[Kasim Awan]

I have a feeling Tuesday isn't modelled very well yet. The uncertainty on Monday contributing to this. From experience these snow systems tend to stall out near their penultimate end & produce prolonged light to moderate snow.

Once the earlier precip has been dealt with we may see these options being shuffled around in a more accurate mannor. 

[Allseasons-Si]

Wow what a difference at 192 from the 12z,...BANK!

now where's that downgrade brigade

 

 

Edited December 25, 2020 by Allseasons-si
typo

[Scott Ingham]

1 minute ago, Allseasons-si said:

Wow what a difference from the 12z,...BANK!

 

Very good run for us Northen boys. First time ive seen a genuine accumalation chance up here. Friday looks like it has potential but it also shows that troughs can pop out of nowhere 

[Mike Poole]

T192:

BANK and BOOM

[Tim Bland]

1 minute ago, Kasim Awan said:

I have a feeling Tuesday isn't modelled very well yet. The uncertainty on Monday contributing to this. From experience these snow systems tend to stall out near their penultimate end & produce prolonged light to moderate snow.

Once the earlier precip has been dealt with we may see these options being shuffled around in a more accurate mannor. 

To be honest Kasim I haven’t seen any models today that show any decent levels of precip on Monday? Most places are shown as having a mainly dry day. Can’t be right surely under a 970 low? Perhaps we are just unlucky and the majority stays offshore ?

[Dazzer6666]

20 minutes ago, Battleground Snow said:

My family have decided to watch Mrs brown boys, so thought it was a good time to pop back on,

18z GFS moves towards the ECM with the low around Newfoundland. Probably not quite enough to make a Greenland high yet tho

 

 

Move out. 

[Mildcarlisle]

44 minutes ago, SLEETY said:

Wow that mean at the end is very reminiscent of the Record cold February of 1895,surely not..

Very tasty charts but  I’m curious,how are they produced from so far back? Are they speculation based only? 

[Kasim Awan]

Just now, Tim Bland said:

To be honest Kasim I haven’t seen any models today that show any decent levels of precip on Monday? Most places are shown as having a mainly dry day. Can’t be right surely under a 970 low? Perhaps we are just unlucky and the majority stays offshore ?

You can be bone dry in a 970mb low as the convection will be mostly around the edges (showery feeds) where the pressure gradient is stepper, and the centre usually more stable like the eye of a hurricane.

In this area ppn will be from shortwaves. Atm Monday looks like an early & late thing for some.

[Mike Poole]

This pub run keeps on giving (almost as if it knows its in Tier 4 tomorrow) at T216:

[Allseasons-Si]

Downstream trough sharpening up off NE states should put more fun into the mix.

[Kent Clipper]

17 minutes ago, dragan said:

i wonder if it’s  BDBM , so pressure is so low it won’t allow precip to form...

It's mid winter meaning there is no solar input to aid convection over land. Coastal areas will be most prone and inland areas too when troughs and other disturbances form. (Such mesoscale features normally only show up within 48 hours). I wouldn't be too concerned.

If it was mid summer under the same setup inland would be a rash of thunderstorms with coasts relatively dry.

Edited December 25, 2020 by Kent Clipper