Model Output Discussion 29th December - Into mid-Winter.

[nick sussex]

Just now, Ali1977 said:

Well GFS is also consistent - jury still out

Downstream yes but its a bit more amplified over the ne Canada at T84hrs, the PV elongation and digging into the Atlantic should occur a bit further west here.

[Dunlop Dave]

Sadly looks like a rain event for us. Payback for the low slider of March 2013 that gave us 40cm in a day and none for you lot !

[MKN]

6 minutes ago, Summer Sun said:

Friday 13th not unlucky for some

For seeing snow falling things are certainly looking good but if that chart prooved correct the majority would be without any lying snow.  Of course the potential after that point is still there to help with that matter. 

[Southender]

26 minutes ago, SN0WM4N said:

Oh god, im unprepared for anything like this.

 

Fingers crossed mate! The snow/rain line is going to change so much between now and then. Hoping for a few flakes, even though it won't settle. First flakes in around 4 years perhaps?!

Edited January 10, 2017 by Southender

[SMU]

GFS at 96 now better & more amplified -

why? - jet profile not split over the atlantic taking the azores up & NE as opposed to cutting through the UK- thats another swing to the ECM...

again...

[Met4Cast]

The improvement upstream early on is leading to a more amplified high. Up she goes towards Scandi at T102!

 

[Just Before Dawn]

This still looks concerning for a North Sea storm surge on Friday - Spring tide between 4 and 7am down the east coast with sustained NNW at 40mph or higher close inshore - one to watch.

[Long haul to mild]

GFS still brings an area of rain, sleet and snow down the Eastern side of the country on Friday morning. Could be some nasty conditions considering the strength of the wind too. Very marginal for ppn type and the mild sector may keep it as rain near the East coast.

[nick sussex]

In your own time GFS, for heavens sake get on with it! zzzzzzzzz

[Ali1977]

3 minutes ago, nick sussex said:

In your own time GFS, for heavens sake get on with it! zzzzzzzzz

This is really annoying and always leaves a worry that it may actually be correct

[swfc]

2 minutes ago, nick sussex said:

In your own time GFS, for heavens sake get on with it! zzzzzzzzz

dont think its there tbh.looks like me after a night out,tired and flat nick!!.

[I remember Atlantic 252]

8 minutes ago, Just Before Dawn said:

This still looks concerning for a North Sea storm surge on Friday - Spring tide between 4 and 7am down the east coast with sustained NNW at 40mph or higher close inshore - one to watch.

Yes, wouldn't be surprised if it was storm named D, 4th one of season

[The Enforcer]

23 minutes ago, Iceberg said:

Hi res has it turning to snow ready and heavy to in places. 

22 minutes ago, Daniel Smith said:

18z definitely upgrading back edge snowfall - It is the GFS though.

Context all important for those precipitation charts: snow risk mostly above 400 metres. GFS always secondary to hi-res models - the likes of Hirlam, NMM, Arpege and Euro4, so accuracy could be questioned at this range. However, I would still rather this system take a more southerly track into France as otherwise its primary achievement is to convert Day 1 of the cold spell into a rain day and to delay the arrival of Arctic air in the southern quadrant of the UK until Friday.

[john mac]

5 minutes ago, nick sussex said:

In your own time GFS, for heavens sake get on with it! zzzzzzzzz

Unbelievable mate isn't it. I reckon it will be summer by the time the GFS catches up with the EUROS!!

[nick sussex]

1 minute ago, Ali1977 said:

This is really annoying and always leaves a worry that it may actually be correct

Yes I know how you feel, generally in easterly disasters one model doesn't want to know at all, in this case the GFS sort of wants to know but is determined to be the centre of attention for a while yet. It may get there eventually but is dragging the drama out.

[The Weather Dragon]

Milder air returning for Sun/Mon & a mid latitude block next week - ECM will catch up tomorrow 

[Snowman.]

18 minutes ago, Southender said:

Fingers crossed mate! The snow/rain line is going to change so much between now and then. Hoping for a few flakes, even though it won't settle. First flakes in around 4 years perhaps?!

My mind draws me to the polar event, but that was gone by lunch.

GFS continues to show a band working south along the east coast. Hopefully we get lucky?

[blizzard81]

1 minute ago, nick sussex said:

Yes I know how you feel, generally in easterly disasters one model doesn't want to know at all, in this case the GFS sort of wants to know but is determined to be the centre of attention for a while yet. It may get there eventually but is dragging the drama out.

And now it has just given up - frozen at 162hrs lol

[Weathizard]

Just now, Jonathan Evans said:

Milder air returning for Sun/Mon & a mid latitude block next week - ECM will catch up tomorrow 

 

Can I buy your crystal ball please?

[tight isobar]

Gfs determined to find the slowest most difficult' unsympathetic route to an easterly..or at least a decent one!!!!

Edited January 10, 2017 by tight isobar

[SMU]

GFS is again slowly picking up the scent of the ECM & lifting the shortwave North at 96 as opposed to cutting it SE- the half step on the 18z means that whilst its not digging SE at 96 its still not fully going NNE ( before cutting SE ) like the ECM - hence some restriction of the ridging...

however that said pidgeon steps add up at 168

18z v 12z sees a light easterly over the SE now from the Theta charts-

just need another 12-18 hours of painstaking small corrections to make the leap to ECM....

 

Edited January 10, 2017 by Steve Murr

[frosty ground]

Just a few hundred miles it.... same pattern as ECM just slightly further south and east..... assume a meeting in the middle and it will get pretty cold with a slight continental drift

[Jason M]

8 minutes ago, nick sussex said:

Yes I know how you feel, generally in easterly disasters one model doesn't want to know at all, in this case the GFS sort of wants to know but is determined to be the centre of attention for a while yet. It may get there eventually but is dragging the drama out.

They are not actually much apart. Just about 250 miles...... In terms of weather at that range that's nothing!!

Trouble is that experience tends to suggest with easterlies you get that small last minute adjustment south, which we can't afford on this occasion. Its interesting though that this run seems to hint at wanting to nudge everything a little north by 180. Maybe not a sinker?

Edited January 10, 2017 by Jason M

[bluearmy]

3 minutes ago, Jonathan Evans said:

Milder air returning for Sun/Mon & a mid latitude block next week - ECM will catch up tomorrow 

Jonathan - is this just an analysis of the GFS runs or do you know something we all don't ? 

[PersianPaladin]

Again, these are small but significant differences in the modelling of the PV split/movement. Currently the GFS persists with the shortwaves jutting out eastwards from Greenland, and this in turn impacts the amplitude of the northern polar front, creating an eastward bow-curve in the northern arm exactly where we don't want it. The GFS will "get there" eventually for Euro continental cold. But it'll be the anticyclonic dry type and with not particularly cold uppers.