Model Output Discussion

[SMU]

http://91.121.94.83/modeles/gfs/run/gfsnh-0-132.png?18

As expected the trough axis is slightly tilted more SW rather than West-

More importantly though more energy in the southern stream now ( ring any bells like the last couple of days the immeadiate timeframe shifted in the 72 hour range to a bit more energy in the southern stream)

now that system over portugal is slowing the trough up & will also slow any system down coming south through greenland-

Window of snow in the SE may run for 30/36 hrs on this run-

Starting at T 123 onwards--

WATCH THAT SOUTHERN ARM HOLD IT UP!!!!!!!!!!!!!!!!

S

[PB22]

The all important T+120 FAX chart: http://www.meteociel.fr/ukmo/fax/fax120s.gif

Looks promising with the cold sweeping in...

[Yeti]

Some nice convection for the East Midlands there!

http://www.wetterzentrale.de/pics/Rtavn1264.png

These synoptics are awesome, just look at that swathe of low heights moving in at 120:

http://www.wetterzentrale.de/pics/Rtavn1201.png

Feeling pretty raw too with the temps and wind:

http://www.wetterzentrale.de/pics/Rtavn12017.png

http://www.wetterzentrale.de/pics/Rtavn1209.png

[John Snow]

Not the slightest sign of a downgrade on this run, if anything its an upgrade

Severe weather is pretty much nailed on now, biggest backtrack in history if doesn't occur now

[Neilsouth]

http://91.121.94.83/modeles/gfs/run/gfsnh-0-132.png?18

As expected the trough axis is slightly tilted more SW rather than West-

More importantly though more energy in the southern stream now ( ring any bells like the last couple of days the immeadiate timeframe shifted in the 72 hour range to a bit more energy in the southern stream)

now that system over portugal is slowing the trough up & will also slow any system down coming south through greenland-

Window of snow in the SE may run for 30/36 hrs on this run-

Starting at T 123 onwards--

WATCH THAT SOUTHERN ARM HOLD IT UP!!!!!!!!!!!!!!!!

S

Agreed this run is bloody fantastic for many , including us in the east and south east

http://www.wzkarten.de/pics/Rtavn11414.png

LOL look at the jet , it's gone so far south :winky:

Edited December 11, 2009 by neilsouth

[LomondSnowstorm]

Not sure about it, snow is not as heavy further north from a personal point of view but it does look good in general, and I guess we would probably see more convective precipitation than shown on this. Still, an upgrade for central England and Wales.

[TEITS]

Brilliant run so far.

If the 18Z verified it wouldn't be snow showers but more organised bands of snow sweeping in from the NE. Seen this many times during the 80's and in one case I witnessed 1ft of snow fall in the space of 3hrs!

[Snowaddict]

Another excellent 18Z run, I can't believe all this in the more reliable 1 - 6 day timeframe....

MUCH better FAX T+120 chart... Excellent in fact with the 528DAM line across majority of British Isles..

Troughts embedded in a stiffening easterly flow..

It's getting close to the timeframe where this can really begin to be ramped up..

STUNNING synoptics!

[Lewis]

Some nice convection for the East Midlands there!

http://www.wetterzentrale.de/pics/Rtavn1264.png

These synoptics are awesome, just look at that swathe of low heights moving in at 120:

http://www.wetterzentrale.de/pics/Rtavn1201.png

Feeling pretty raw too with the temps and wind:

http://www.wetterzentrale.de/pics/Rtavn12017.png

http://www.wetterzentrale.de/pics/Rtavn1209.png

Lovely is it not? Breath taking!!!

The temps on the projected charts are way to high especially towards the E coast, expect them a good 2-3c below across the country.

Lewis

[Nick F]

18z an improvement for the cold wave later next week (Thurs) with the low coming into Biscay taking a more southerly track than 12z GFS across N Spain which in turn allows colder air to come further south as it advects west and advect west quicker with stronger flow. Dream charts towards late next week ... -15C T850s in touching distance of SE England, shame it's so far away to verify.

[bluearmy]

The all important T+120 FAX chart: http://www.meteociel.fr/ukmo/fax/fax120s.gif

Looks promising with the cold sweeping in...

indeed - the lower dam has spread infront of the occlusion and the inflection point is in the centre of the shortwave which as sm has intimated, could be a bit further se. might we hope for the whole lot to be white ????

oh and by the way the shortwave coming roud the top of the block on the 18z after the ridge is further east so less risk of the west based - NAO to follow in FI

Edited December 11, 2009 by bluearmy

[SP1986]

This is either going to be one of the best cold spells/snaps in recent times, or going to be the biggest failure anyone has ever seen.

I would say the ECM probably isn't trustworthy at this stage, it's changed around flip flopping, it's not worth taking its run seriously. I think until the ECM builds on a solid run, it's output can be binned.

The GFS is definitely the leader on this one.

[Harsh Climate]

Looking at the biggerpicture for the UK as a whole, this run is an upgrade!

http://www.wetterzentrale.de/pics/Rtavn1441.png

no deep low pressure heading into scandanivia, should encourage further northern blocking as a result.

Edited December 11, 2009 by Jed Bickerdike

[cyclonic happiness]

OMG!!!! what the dickens is going on?

I keep looking at runs and every time find a new solution??!

The one thing that has remained steady is "cold", are the models really so bad at setting us out anything that is set in stone?

We have lost a huge MASSIVE low that was in the 12z ataround the northeast of iceland to be replaced with...well...not alot??? nothing?!!!

I'm not complaining, but this is a bit weird??? It does give us a better chance at prolonged cold though IMO.

Look!!

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=6&code=code&mode=0&mode3h=&carte=1&runpara=

[Altostratus]

Much better run for those in the south. Starting to look very exciting indeed. I arrive at Heathrow on thurs lunchtime - I couldn't have picked a better day and time - perfection!

[SMU]

Lovely is it not? Breath taking!!!

The temps on the projected charts are way to high especially towards the E coast, expect them a good 2-3c below across the country.

Lewis

Let see how interestingthis gets-

Im betting that we see a -10C minima over the midlands on the 156 chart-- Anyone got the high res yet- PERFECT PERFECT conditions-

Slack air-

Snowcover-

Bitter uppers-

S

[Duncan McAlister]

This is either going to be one of the best cold spells/snaps in recent times, or going to be the biggest failure anyone has ever seen.

I would say the ECM probably isn't trustworthy at this stage, it's changed around flip flopping, it's not worth taking its run seriously. I think until the ECM builds on a solid run, it's output can be binned.

The GFS is definitely the leader on this one.

Since I've started model watching it's always the GFS that comes up with dream synoptics and the ECM more cautious.

Could it be a case of 'even stopped clocks are right twice a day'?

[Bartlett Low]

This is AWFUL for north west

Unfortunately for us in the North West we may have to miss out in the short term to gain in the long term.

The overall synoptics are excellent for the whole country.

Still scope for snow in the north west from this set up. Patience will be required.

Once again, its the overall picture that is important here.

[k19]

Anyone know what this will hold for the northwest? Looks like the pennines are steeling our snow to me...

[John Snow]

It is time the Met Office started briefing the media and putting out alerts about next week, the levels of snow and disruption unless there is a major downgrade is going to dwarf last Feb

[Harsh Climate]

http://www.wetterzentrale.de/pics/Rtavn1502.png

wooah is that a -15 850 temp i see there in central england ??

[cyclonic happiness]

Unfortunately for us in the North West we may have to miss out in the short term to gain in the long term.

The overall synoptics are excellent for the whole country.

Still scope for snow in the north west from this set up. Patience will be required.

Once again, its the overall picture that is important here.

Don't worry, with the currant charts the northwest will be just as badly hit (goodly??) as everywhere else.

[cold snap]

Does 18Z want a nationwide event?

Because i cant work it out.how far does the 18Z push it in?

[Duncan McAlister]

http://www.wetterzentrale.de/pics/Rtavn1502.png

wooah is that a -15 850 temp i see there in central england ??

On closer inspection it looks like a -10C

[Geordiesnow]

Looking at the biggerpicture for the UK as a whole, this run is an upgrade!

http://www.wetterzentrale.de/pics/Rtavn1441.png

no deep low pressure heading into scandanivia, should encourage further northern blocking as a result.

I'm not too sure if it's an upgrade on the UK as a whole as it sinks the easterly flow quicker but it is another good run.

Although it's only one run but the GFS shows a low heading along Biscay and into France, this may come into play in future runs and may keep the easterly going for longer.