Winter Model Discussion 06Z 10/01/13>

[The Northern Ramper]

Some have said the ECM has downgraded this morning, however this is not how I read it.

The ECM is still sending the shortwave south east and this mornings run is another variable, it doesn't look as clean and I think has found the signals the Gfs has been reading.

The Gfs though is over cooking its reaction to these signals and I think we will now see some movement towards the ECM.

There may still be further movements after this from both models.

The other thing to consider is whilst the models are at their most uncertain the ukmo is currently leading the verification stats. The ukmo is having none of this drama.

[Isolated Frost]

Thanks GP – strongly disagree with the assessment for next week – don’t forget in December that the Cheltenham meeting that you thought would be off due to snow ended up being ran in double figure temps and pouring rain !

I hope you are right with your assessment and going forward with the blocking but I really can’t see it.

The ECM and UKMO dont.

[karlos1983]

For interest

@MattHugo81: Just 11 of the 51 EC ENS members support the GFS in terms of bringing in a milder, Atlantic flow...

@MattHugo81: The other 40 members between Tue-Thu of next week either show a 'slider low' or the bulk of the members (21) show an E or NE'ly flow.

@MattHugo81: Milder solutions do become more evident by the end of next week, but clearly that is in the realms of no-mans-land at the moment...

From my point of view it's always important to see the view if professionals, certainly helps me to keep my sanity somewhat

[NO LONGER POSTING]

11 of the 51 EC ENS follow a more milder solution..So (if my maths is right) 5.6% and it's FI. Still all to play for in my book.

[Buzzit]

11 of the 51 EC ENS follow a more milder solution..So (if my maths is right) 5.6% and it's FI. Still all to play for in my book.

Think you will find the % more like 20%

[Southender]

For interest

@MattHugo81: Just 11 of the 51 EC ENS members support the GFS in terms of bringing in a milder, Atlantic flow...

@MattHugo81: The other 40 members between Tue-Thu of next week either show a 'slider low' or the bulk of the members (21) show an E or NE'ly flow.

@MattHugo81: Milder solutions do become more evident by the end of next week, but clearly that is in the realms of no-mans-land at the moment...

From my point of view it's always important to see the view if professionals, certainly helps me to keep my sanity somewhat

So clearly the GFS is still the rank outsider.

No cause for alarm just yet.

However we need to see the GFS falling in line by the 00z output I feel. And the EC and UKMO remaining solid with regards to colder conditions.

[NO LONGER POSTING]

Think you will find the % more like 20%

I was just doing the maths and I think i made a mis calculation it didn't look right lol i think 1% is 5.1 so its around 12%

[nick sussex]

Given the timeframes involved regardless of the balloon data issue a very important GFS 06hrs run coming up.

Before that this just in from the NAM for T84hrs from the 06hrs run:

Compare that to the earlier GFS for 90hrs:

[Methuselah]

[Nick B]

I was just doing the maths and I think i made a mis calculation it didn't look right lol i think 1% is 5.1 so its around 12%

(11 / 51) x 100 = about 21.6%.

Still a healthy enough percentage of around 78.4% not going with a mild solution.

Edited January 10, 2013 by Nick B

[No Balls Like Snow Balls]

Given the timeframes involved regardless of the balloon data issue a very important GFS 06hrs run coming up.

Before that this just in from the NAM for T84hrs from the 06hrs run:

Compare that to the earlier GFS for 90hrs:

What am I looking for Nick?

[offerman]

Weird, Thought i`d posted earlier but not showing?

Just mentioned that snow even will be small and that ecm charts look better for predicting snow than gfs. Goes back to what i said earlier in the week about not getting hopes up to high for cold as it can all change quickly as happened in December and has happened again now with what GFS showed before.

P.S looks like flood risk returns for next 1.5 weeks to. So be prepared just in case as waters tables remian topped out, lots of roads still have water run off where i live from the fields.

[Wayneywoo]

You can clearly see here all the models and how they differ at around T+96 http://www.meteociel.fr/cartes_obs/comp_panel.php?mode=0&ech=102&size=2

Crucial we see how the LP's are handled off the NA East Coast...

[fromey]

Given the timeframes involved regardless of the balloon data issue a very important GFS 06hrs run coming up.

Before that this just in from the NAM for T84hrs from the 06hrs run:

Compare that to the earlier GFS for 90hrs:

sorry to ask, im not very good at spotting the difference, is it the low pessure off the N/E??

fromey

[Snowman31]

Given the timeframes involved regardless of the balloon data issue a very important GFS 06hrs run coming up.

Before that this just in from the NAM for T84hrs from the 06hrs run:

Compare that to the earlier GFS for 90hrs:

Is that bad?

[Snowmaggedon]

What people must remember is that the Met Office believe that this weekends cold spell has nothing to do with the SSW, so if there is any mild incursion next week it may only be temporary until the effects of the SSW are seen

[Nick B]

Given the timeframes involved regardless of the balloon data issue a very important GFS 06hrs run coming up.

Before that this just in from the NAM for T84hrs from the 06hrs run:

Compare that to the earlier GFS for 90hrs:

Look at the pressure change around Greenland - a good 10mB in the right direction. The low off the Eern seaboard helping to start reinforce the GH. In addition the low further south east is directing energy in a much more N/S direction. Basically more amplified.

Edited January 10, 2013 by Nick B

[Catacol]

Yep - its a fascinating period of model watching, and Gibby has it spot on: I dont recall either in my 9 years of model scanning seeing such a start contrast between the models at such a short time frame.

However we are still in a situation of ECM/UKMO supporting a block to the north with low pressure to the south (small scale surface features aside of course) and GFS going for the opposite. Amazing that this has been sustained overnight. Of the lesser models GEM goes with the block and JMA looks... well - to be honest it looks downright confused!

I still think the block will win out with energy sliding SE underneath, but then again I thought that in December and we know what happened then! However - to me the GFS pattern just looks too flat. That is a gut feeling - nothing more - and it may also be relevant to know that the Met Office never use GFS in their forecasts. GFS also still sitting below both ECM and UKMO in verification stats.

All this suggests to me that the block will win out.

[nick sussex]

What am I looking for Nick?

What am I looking for Nick?

The pattern in the ne USA because thats crucial for the shortwave heading se from Iceland and also impacts troughing in the west Atlantic.

The NAM is far better than the earlier GFS run.

You want the deeper low of the NAM and less shortwave energy trailing behind, also note the better ridging between the trough off the eastern USA eastwards.

Edited January 10, 2013 by nick sussex

[jethro]

I could have sworn that the outlook has always been for this weekend to be cold and possibly snowy for some but that this was expected to be a short term thing, a winter bonus, nothing to do with strat warming. Thereafter it was likely to warm up again for a week or so but that there was then potential for the weather to turn cold, possibly very cold with possibly snowy weather thrown in too towards the end of the month and into February.

Not being someone who gets drawn into the seesaw ride of watching every model run, preferring instead to accept the wiser, broader views of the likes of JH, GP and Ian F, I can't see that much has changed in the forecast. Folk moan about forecasts being wrong but then seem to skip over ones which were right. Now I'm not saying I can see into the future and their forecasts have verified about this period but so far, they're on the money.

[Southender]

Given the timeframes involved regardless of the balloon data issue a very important GFS 06hrs run coming up.

Before that this just in from the NAM for T84hrs from the 06hrs run:

Compare that to the earlier GFS for 90hrs:

Any chance of an explanation Nick please?

HP ridging better in between the Atlantic depression and the one coming off the Eastern seaboard? Causing it to split and hopefully allowing height rises in the key area. Sending the troublesome SW sliding down towards the UK ala EC and UKMO?

Or have I got that completely wrong?!

Edited January 10, 2013 by Shrimper

[lord stratus]

Some have said the ECM has downgraded this morning, however this is not how I read it.

The ECM is still sending the shortwave south east and this mornings run is another variable, it doesn't look as clean and I think has found the signals the Gfs has been reading.

The Gfs though is over cooking its reaction to these signals and I think we will now see some movement towards the ECM.

There may still be further movements after this from both models.

The other thing to consider is whilst the models are at their most uncertain the ukmo is currently leading the verification stats. The ukmo is having none of this drama.

Quite right. I think we are all guilty of micro managing upcoming weather events, especially cold weather. I believe the gfs will back away from zonal somewhat and settle into a middle ground. I think we should have one eye on bbc latest forecasts also as this will help pick up on a particular trend rather than us all hanging on every single output

[Methuselah]

All future posts regarding 11/51 will be deleted...

Edited January 10, 2013 by Rybris Ponce

[SMU]

Morning All-

Took a time out overnight & have just logged in & yes.

NO CHANGE. ECM very snowy although that snow margin has moved to the east & SE as opposed to the west for the fronts-

The UKMO & GEM are awsome & then we come round to the GFS..... what a stinker, although upgrades in the midterm-

Ive also noticed the PPN shunted back a bit on the UKMO & GFS & a more fragmented low with isolines at a SE angle as opposed to a circular low-

This will suck up the continental undercut quicker so for T60 ( although ideally the 54 chart at 06z sat)

http://www.meteociel.fr/ukmo/run/U60-594.GIF?10-06

We get the PPN into 528 air & surface charts

http://www.meteociel.fr/ukmo/run/U60-580.GIF?10-06

so again roughly a line from kent out to glouceser looks set fair for snow with places like the chilters / downs etc doing well-

Further out ECM PPN here

http://en.vedur.is/photos/atlant_evr_urkomuspa/130110_0000_120.png

need it to move west a bit! -

& the UKMO is perfect for the UK as a WHOLE

http://www.meteociel.fr/ukmo/runs/2013011000/UW96-21.GIF?10-06

In summary chart term snow potential high, upgrades for cold & snow in the mid term, post day 5 no resolution- but COULD be a lot of snow

S

[jimben]

What a bewildering (but fascinating) time for a newbie to start chart watching! Anyway, I have GFS/ECM/UKMO open in 3 windows and as I step through I can see the divergence emerge after T48.

At T72, ECM begins to do its own thing, but GFS and OKMO are still close (to my novice eyes).

UKMO

GFS

It's then that things begin to really change, but it seems a shame to me that neither UKMO nor ECM provide the 6h or 12h updates at that stage as GFS does so you can really watch the evolution in detail. So the question it leaves me is, leaving the models aside, are there any compelling physical reasons why that low would track E/NE rather than SE?

Others take note. What an excellent post.