Model Output Discussion 17th Dec.2013-12z onwards.

[phil nw.]

A new thread then ready for the 12z runs due out anytime now.

 

Usual requests to keep on topic folks and be polite to each other,tis the season of goodwill after all.

 

OK then continue when ready.

Edited December 17, 2013 by phil nw.

[Cecil Hogmanay Melchett]

NAE at least gives many in North western Britain some falling snow through Thur.

Unfortunately the accumulation charts are green but would be nice to see snow falling from the sky

Edited December 17, 2013 by happy days

[legritter]

A new thread , lets enjoy what the models throw at us in this very interesting disturbed spell over the coming week or so .plenty on offer going by todays output and Data ,and plenty of surprises in the very quickly mobile synoptic situaton that could gradually get colder if those colder 850 s come a visiting .

[Paul]

We've updated our GFS charts in the last 24 hours, hope you like them (more additions and upgrades to follow).

 

http://www.netweather.tv/index.cgi?action=nwdc;sess=

[karyo]

The 12z GFS out to 144 hours has moved everything further north with more pronounced high pressure over the continent. Not as good for cold zonality.

Karyo

[Cheshire Freeze]

Lurking with intent....

 

[Cecil Hogmanay Melchett]

The 12z GFS out to 144 hours has moved everything further north with more pronounced high pressure over the continent. Not as good for cold zonality.Karyo

Agreed K.

Not a good start to the 12z's.

[bradymk]

The 12z GFS out to 144 hours has moved everything further north with more pronounced high pressure over the continent. Not as good for cold zonality.Karyo

More of a ridge in the atlantic though with trough digging deeper in W Europe.

[Cheshire Freeze]

The 12z GFS out to 144 hours has moved everything further north with more pronounced high pressure over the continent. Not as good for cold zonality.Karyo

 

Yes but could have ramifications into FI...keep your eyes peeled for a potentially wintry low res.

[karyo]

Let's hope so guys.

[Cecil Hogmanay Melchett]

Yes but could have ramifications into FI...keep your eyes peeled for a potentially wintry low res.

How so?

No idea why your suggesting this based on the current data to hand?

Hope your right though cc.

[johnholmes]

Yes but could have ramifications into FI...keep your eyes peeled for a potentially wintry low res.

 

maybe someone will bet you a fiver and then a further fiver that whatever GFS FI shows will not occur?

[Cecil Hogmanay Melchett]

Pretty awful gfs 12z with the jet further north,nowhere near as good as 06z

Hopefully ukmo will be better!

[johnholmes]

Lurking with intent....

 

 

are you referring to the upper ridge in the Newfoundland area with the next developing low underneath it or hopecasting that a ridge will develop out of nowhere after the first surface low?

[MR EXTREMES]

the gfs has thrown a spanner in the works but does show if correct colder upper not much but enough for snow at elevation in the far north its certainly more of a downgrade for those in the north after yesterdays runs although it is only one run.

 

the main feature will be the wind and rainfall amounts which will be of concern to the uk met.

 

over all though northing prolonged with deep cold just flirting visits from lower upper air temps and snowfall likely for higher on the hills in northern areas but could well be flood warnings in place by the big day its self no above average temps so certainly feeling chilly.

 

frost at a minimum to.

 

the latest chart from the gfs does look a little exciting but 99.9% likely not to happen with the volatile nature of the weather at the moment you would be better sticking with the ukmo.

 

I still see no hlb in any of the charts this is still very unlikely for sometime yet.

Edited December 17, 2013 by emotional rollercoaster

[Cecil Hogmanay Melchett]

are you referring to the upper ridge in the Newfoundland area with the next developing low underneath it or hopecasting that a ridge will develop out of nowhere after the first surface low?

CC baffled me with that post for sure JH.

1Z wipes out the hope of snow for even those up north!!

[Cheshire Freeze]

How so?

No idea why your suggesting this based on the current data to hand?

Hope your right though cc.

 

Hi HD, I was expecting heights to be lifted to our N around the top of the UK troughing. Although the GFS sort of gets there/sniffs out potential, the UK doesn't really benefit.

 

 

maybe someone will bet you a fiver and then a further fiver that whatever GFS FI shows will not occur?

 

Bit unfair John

[karyo]

Yes, the high pressure over southern and eastern europe puts a stop to the Atlantic trough from moving further east. As a result we are constantly under southwesterly winds.

Quite often the models show the jet travelling south and east but tend to take it back west in the reliable timeframe.

Karyo

[johnholmes]

I am afraid that reference to what the upper air pattern has and continues to show, amidst all the changes on the synoptic outputs is the only sure way to see what is happening in the bigger picture with the UK just a tiny part of this.

Overall the tendency is for the upper air to cool slowly and slightly, thus allowing the jet to edge a shade further south with time. This will increase the probability of, chiefly to the rear of these deep depressions, snow to fall on high ground and, as with the comment above, for this to edge a little further south with time. How far south is impossible to judge at this stage, if it is Xmas Day you are interested in. Eight days away, a lifetime in terms of detail as most on here should understand by now.

Best estimate IF mas Day gives weather to the rear of a low rather than ahead of one, is for some passing snow at low levels down to the Grampian region, hills further south, possibly as far south as the Peak District. Transient only away from the mountains though.

Realistic this in my view but do feel free to shoot the post down.

[Cheshire Freeze]

are you referring to the upper ridge in the Newfoundland area with the next developing low underneath it or hopecasting that a ridge will develop out of nowhere after the first surface low?

 

I suspect it was obvious to most people I was on about the deep low to the W of the UK? Hopecasting and ridges? The world of meteorology doesn't revolve around cold weather John....as you should know having worked for the Metoffice.

[MR EXTREMES]

it cant make it crewcold because theres far to much residual energies and still a fairly strong jet its not going to happen just yet.

 

and as karyo said European heights just an endless stream of low pressure coming across the alantic and azores running west to east its not good for most.

 

to be fair crewcold I thought the same thing as john in reference to your post theres really no sign of any kind of block except euro and azores.

Edited December 17, 2013 by emotional rollercoaster

[johnholmes]

Hi HD, I was expecting heights to be lifted to our N around the top of the UK troughing. Although the GFS sort of gets there/sniffs out potential, the UK doesn't really benefit.

 

 

 

Bit unfair John

 

why, nothing you have shown suggests your probability has any real prospect of happening-to me that is hopecasting not trying to forecast what the meteorology suggests?

Look at the long wave pattern you show, the height pattern of I think it is the 558 or 552dm line. Is that likely to alter to allow an upper dige, what probability would you put on that? What probability that the long wave pattern remains about the same feeding a series of surface deep lows?

[Cecil Hogmanay Melchett]

Hi HD, I was expecting heights to be lifted to our N around the top of the UK troughing. Although the GFS sort of gets there/sniffs out potential, the UK doesn't really benefit.

 

 

 

Bit unfair John

I see.

At the moment all on offer to my eyes at the very best is transient PM air if the jet digs far enough south(ala 06z GFS).But even then it will be transient in nature as the blocking is just not on offer to 'keep' the southern arm in command.

In essence,until we see a huge change in the NH profile we are up the swanny without a paddle,so to speak.

An awful awful pattern to be stuck in at any time of the year.

This December will certainly go down as 'one to forget'.

My mind is already focused on Jan and no matter what anyone says the early part (at least)ain't looking great either.

[Barry12]

UKMO has -4 uppers for a lot of the UK throughout Thursday - snow possible over higher ground.

 

[Cheshire Freeze]

why, nothing you have shown suggests your probability has any real prospect of happening-to me that is hopecasting not trying to forecast what the meteorology suggests?

Look at the long wave pattern you show, the height pattern of I think it is the 558 or 552dm line. Is that likely to alter to allow an upper dige, what probability would you put on that? What probability that the long wave pattern remains about the same feeding a series of surface deep lows?

 

I haven't got the willingness to go to great lengths to annotate what I was seeing towards the end of hi-res but you could clearly see that the ridging further N of the high to our east was promoting spats of higher heights round the top of our troughing.......something I believe even Bluearmy has pointed out over the past few days. I wasn't summarising the NWP as a whole or hopecasting in the slightest...merely commenting on one run. Don't understand why you have to constantly try and undermine or snipe at others when they have a differing view to your own?