Model Output Discussion 12z 04/12/2012

[london-snow]

This is what i was saying earlier. The more westward the pattern the better.

The models have a history of moving a pattern far too east, However in time the pattern gets modeled further west each run as things firm up as we enter the later part of reliable.

Expect further upgrades on the 00z and the UKMO & ECM to start coming inline with the GFS.

[Wilxy]

Its hard not to ramp when a run like this comes along but, the trend is still going strong.

[TEITS]

The UKMO fax charts look very similar to the raw output.

It would have been nice to see those modified away from the raw output. Ian F if you're about a question, was there any talk about modifying especially the 120hrs?

If I was honest Nick 99% of the time the fax charts always go with the raw output. Remember last winter when many of us knew the UKMO was wrong being an outlier and yet for some reason the Met O still backed the raw output.

Such is my confidence that the UKMO/Fax chart is wrong I have saved it onto my HDD for another day!

[bluearmy]

The way the 18z deals with the shortwave at t120 compared to the new fax, makes it fairly implausible in it's quickness. I recall saying something similar re the 18z run at the weekend which drove the WAA to create the Atlantic ridge.

[Snowy Liverpool]

Oh lord, snowmageddon for the south at 240

[ITSY]

Blizzard anyone?

[karlos1983]

WOW, not counting my chickens yet, seen these never come good before, but WOW, that is a thing of beauty, and we are only 4 days into winter ladies and Gents!

[Matty M]

Ummmmmmmm the 18z FI looks so unrealistic it puts a question mark over the higher resolution part.

Bin the run after 192hrs as the evolution looks extremely unrealisitc.

[nick sussex]

seems like i have been looking at those CPC charts for about a month now with people posting them in here i dont think they have ever come off

Well they just give a representation of the overall expected pattern, they don't give specific detail re the finer things like shortwaves etc.

Of course like any forecast they're not always going to be on the money but given the background signals they do have a chance of verifying.

[If Wishes made Weather]

And by 252 we end up with some low pressure being dragged from the south over the UK lowering heights and upping the PPN, a lobe of PV being pulled down into far eastern Europe/western Aisa ready to be pulled south and round teh scandi high, and 0c 850s have made it accross the Atlantic from the east to the west, as well as an easterly gale over the UK.

Dont be depressed tomorrow when things downgrade.

[weatherguy]

Ummmmmmmm the 18z FI looks so unrealistic it puts a question mark over the higher resolution part.

Bin the run after 192hrs as the evolution looks extremely unrealisitc.

Happily...I could look at the 192 chart all night!

[Bristawl Si]

Blizzard anyone?

Ooohhhh! Retro chart - i'll dig out my Specials records!

[ITSY]

haha you couldn't make this stuff up. The above blizzard, followed by a channel low, followed by a reload:

None of that will happen, of course, but to see it modeled is quite amazing

[cold snap]

Norty gfs going to the pub on a school night

I don't think I've ever seen such a epic run .fautless smooth transition to the next ice age

[karlos1983]

And by 252 we end up with some low pressure being dragged from the south over the UK lowering heights and upping the PPN, a lobe of PV being pulled down into far eastern Europe/western Aisa ready to be pulled south and round teh scandi high, and 0c 850s have made it accross the Atlantic from the east to the west, as well as an easterly gale over the UK.

Dont be depressed tomorrow when things downgrade.

Perhaps, but it completely loses the plot after +192 - +204, really doesn't make much sense to me....but I'm no expert, that would take some downgrade surely to get away from an easterly now.

[Fred Sykes]

WOW, not counting my chickens yet, seen these never come good before, but WOW, that is a thing of beauty, and we are only 4 days into winter ladies and Gents!

So, a few hours ago everyone was swallowing their Prozac, and now they're spitting it out!! I suspect some will be licking it off the carpet tomorrow morning! Talk about a change in mood! lol

[Cloud 10]

Note the strat polar vortex moving towards siberia as the run progresses which

could have big implications as we head towards christmas!

[kold weather]

Well an interesting GFS run, all sorts of slightly mad things happen later in the run BUT importantly it keeps the same set-up the 12z did within 144hrs, thats the key area where this whole thing could go wrong. If the PV extends a little too far east its going to shunt the whole lot eastwards and we'll be fighting to just get the scraps of any SE/ESE airflow we can get rather the full hog roast.

[TEITS]

The way the 18z deals with the shortwave at t120 compared to the new fax, makes it fairly implausible in it's quickness. I recall saying something similar re the 18z run at the weekend which drove the WAA to create the Atlantic ridge.

Even I admit the 18Z might be a bit progressive in the speed of the shortwave and the resulting E,ly. However I feel the UKMO is the reverse and the BOM takes it NE. So overall a middle ground might be correct here, so instead of an E,ly at +144 like the GFS shows and the ECM at +192, maybe around the +168 timeframe is when an E,ly could arrive (11th Dec).

Edited December 4, 2012 by THE EYE IN THE SKY

[karlos1983]

So, a few hours ago everyone was swallowing their Prozac, and now they're spitting it out!! I suspect some will be licking it off the carpet tomorrow morning! Talk about a change in mood! lol

It's been emotional, I'll tare my remaining hairs out when this doesn't verify

[ronan]

Note the strat polar vortex moving towards siberia as the run progresses which

could have big implications as we head towards christmas!

Can you explain what these implications would be? Thanks.

[cyclonic happiness]

Lol! this is getting truly annoying now, can we get a run that we can bank now and verify later as well please?

It's a thing of great beauty to look at though isn't it?

The pendulum keeps swinging though

[SnOwFeSt]

The size of the block is huge. Great to see some linking of the heights in the mid Atlantic with the Siberian high moving westward. It makes the margin for error much larger, and one would expect some sort of easterly to materialise from this.

Obviously the earlier runs have been relatively disappointing, and this has been a stonker, so perhaps it would be realistic to expect something in between?

[If Wishes made Weather]

Its a scream at the end of the run - Atlantic blocked, Scandi/Baltic high, Greenland high, PV all over the place, but mostly now over the pole having migrated and -28 or colder 850s just to the north of Iceland apparently heading south!

[ITSY]

Can you explain what these implications would be? Thanks.

It would mean a general east to west airflow - which for us is likely to spell cold weather