Winter Model Discussion - Cold Hunting -12Z 06/01/13

[mcweather]

We have been told by those with the best knowledge like Ian F that the models will flip about in their output through the transition to colder conditions so it is no surprise to see tonights ECM. We all know that we would like to see the big three home in and focus on one solution but at the moment we seem to get two out of three at any one time tonight it was the ECM'S to be the odd one out. It is worth remembering we are still at the very beginning of the transition to colder conditions and that the worst of those have not been predicted to happen till later in the month once the SSW effects really propagate into the tropospheric pattern so whilst I am as impatient a the next coldie to see things get a move on I think those who show patience will be amply rewarded.

The way to look at it is like this. If you were promised a repeat of the winter of 1947 would you be complaining at a mild chart at the beginning of January?

Whilst I am not saying that we will get a 47 repeat, there never the less remains an excellent chance that we will see some decent cold and snowy weather between now and mid march. Try not to live every run otherwise you'll all be too exhausted to go out and play in the snow when it does come!

Edited January 7, 2013 by mcweather

[ChartViewer]

Uncertain CMA T72 chart

Every frame takes ages so i reckon well be at T120 at about 4am...dont wait up ......Not sure what Bejing are up to!

Edited January 7, 2013 by ChartViewer

[Iceni]

After the 15th, huge scatter, but mostly on the right side of the 0ºC line.

[weather eater]

You're acting like that run was terrible..it's not, infact it's pretty good up to +144, anything other than that, which has been said a million times is FI and is highly unlikely to verify. Possible Easterly this weekend with snow for places.

FI is unlikely to verify ever at least in my book, what we are looking for is some sort of consistency, a way of ascertaining what the broad pattern will look like for about the next 5 days and that is proving pretty elusive, a couple of runs maybe, then the dam eel slips away again and we are groping thin air.

[Tim Bland]

£50 says ECM op is a mild outlier on the ensembles...any takers?

[High Altitude]

Between 72-96 the big 3 broadly have the same idea with lows tracking south and a ridge to the north. After this is FI however looking at the jet stream and on the same basis that + t96 is FI then I see a window of opportunity for the high to retrogress towards greenie as the jet slackens between 96-120.

By this time we 'may' start to see the SSW starting to influence the pattern reinforcing this retrogression.

[lorenzo]

Lorenzo,

How can you say that the ECM is underwhelming tonight?

Because fantasy island is not showing the right pattern you expect?

.........

Thanks London Snow, not meaning to be miserable and am certainly not miserable about the model output, just had hoped for something a little more entertaining that that low powering up at 168, I agree the output at 120hrs is good and the cold uppers are never too far away and of course can be nudged a couple of hundred miles west/east from run to run. From a purely local perspective I prefer the JMA ideas, so in comparison ECM underwhelming.

Guess I still have the solution from the weekend where the operational led the cold pack before bouncing to the top of the milder cluster of ensembles. Was looking for more activity from the Kamchatka ridge making inroads to the Arctic whereas on this run an army of short waves stop that idea.

[on the coast]

These wild swings are surely what Ian F was talking about a few days ago?

[Chris K]

By all means talk about what the models are showing but please, please be careful how you word things, because clearly some people are taking the later frames in F.I seriously even with the HUGE uncertainty fairly early on at the moment.

Look how far we are from a week or so ago with pretty much a pure zonal outlook back then!!!! The fact we have potential should have people drooling enough..... if it doesn't materialise? Well that's how the nature of this science - full of unpredictability.

Anyway, a couple of tweets from some known names to add into the mix:

Brian Gaze:

Lol! ECM 12z looks like bringing the blowtorch back at t+240. Run likely to be an outlier, but still worth noting.

Gavin Partridge

As I said in todays video, "best leave next weeks weather alone for the time being" Concentrate on weekend.

[Grimsby Snow Lover]

£50 says ECM op is a mild outlier on the ensembles...any takers?

Well Matt Hugo seems to think the same as you for what its worth

Matthew Hugoâ€@MattHugo81

Given recent EC ENS I have a distinct feeling the 12z ECM will be a mild outlier...Time will in about an hr.

[Southender]

With the Strat currently the same temperature as London. No wonder we are getting these wild swings. All output past about 5 days should be ignored completely.

[Iceni]

The weekend is looking uncertain....let alone Feb lol.

Sun to strong in Feb anyway lol

#

The sun is NOT too strong in February — the hours of daylight start increasing again, that's all. Some of the best snow events ever have occurred in Februarys over my life time — in fact January 31st 2003 sticks in my memory as the day the M11 was shut down and when I finally got to the station where my car was, I had to scrape 15" of snow off it to open the door and we were snowed in for nearly a week.

Edit. Just looked at the date of the chart and realised you were being ironic. Apologies.

Edited January 7, 2013 by Iceni

[cooling climate]

Must say I think the ECM operational has blown it tonight. The difference between the

GFS and the ECM is that the American model phases the the low in the atlantic with

the one coming out of the states allowing heights to rise to the north from the Azores

rigde. The UKMO looks as though it would do the same.

The ECM on the other hand phases the Atlantic low with the low to the south of

Iceland moving it eastwards and flattening the pattern.

The ECM got this area wrong a couple of days ago when we saw the ridge building into

Greenland and I suspect it will be wrong again.

[Isolated Frost]

Mesoscale modelling time !

GFS solution brings the upper low into SW England for d5 (12z, 12/01)-

Precip generally reflected to the NE of the low, in SW England and a signal for heavy precip in central and eastern parts, some light convective precip across the NE at this timeframe also

The golden '10c' is progged just off the north-east coast (in line with the -4c 850 temps), with 12c generally accepted around the upper low as 'snow' conductive as well.. this precip will fall mostly as rain across SE England on Saturday on current modelling

The EC solution does not do the upper low to the extent of a separate circulated sub-540dm upper low in the channel- a progressive answer with -7c 850s into the NE by Saturday 12z- to me this signifies the notable difference in short-term modelling in regard to the upcoming easterly incursion.

The upper low intact well on the EC solution, though more significant at a lower level, I'd suggest rain turning to snow in south and eastern areas with some notable bands following, with convective snow shrs in the north and east

What must be expressed is confidence in such a solution is low with the volatile outlook- though it's likely that parts of eastern Scotland and England, potentially pushing inland, could experience wintry showers, and snow at times in the upcoming weekend, with the prospects afterwards very much up in the air

[tight isobar]

Oh, dear for persons to be writing off winter at this stage, is somewhat ludicrious. In former post i suggested i was looking forward to the ecm/gfs 18z tonighwt and agree on ecm being underwelming,but again this can be fully expected in regards to ssw,and the like thats one reason i was exited in beleive something of that nature may manifest.dont hold myself to it but shocked i would,nt be if by the end of the 18z, things again were way on track...

[ANYWEATHER]

The pivitol turning point for cold coming in from both gfs and ecm is about Saturday. Pointless looking beyond that because that is well and truly deep into FI.

[phil nw.]

A couple of posts have been deleted because they added nothing to discussion. .

Let`s keep it calm peeps.

If you want to express disappointment then include some model proof or simply post in the moaning thread.

One line gripes or moans are not welcome and will be deleted.

Ok Thanks

[london-snow]

Thanks London Snow, not meaning to be miserable and am certainly not miserable about the model output, just had hoped for something a little more entertaining that that low powering up at 168, I agree the output at 120hrs is good and the cold uppers are never too far away and of course can be nudged a couple of hundred miles west/east from run to run. From a purely local perspective I prefer the JMA ideas, so in comparison ECM underwhelming.

Guess I still have the solution from the weekend where the operational led the cold pack before bouncing to the top of the milder cluster of ensembles. Was looking for more activity from the Kamchatka ridge making inroads to the Arctic whereas on this run an army of short waves stop that idea.

Thanks for the reply Lorenzo

The way i view things especially in these types of situations is that if we take all the output post 120+ and get a mean that mean would be balanced and favored colder conditions.

Then and rightly so you have to ask yourself could the 168+ be correct = Highly doubtful considering previous output and possible rare filtering signals into the data. Could well be a early defaulter back to mild. I would be very surprised to see it have some support in its ensembles which are due out soon.

Keep up the good work & thanks again.

L-S

[Paul]

I know I'm like a stuck record, but please can we keep it on topic - ie about the model output in here. Moans and whines, emotional outbursts and the like need to go into the model mayhem thread which is setup for just that sort of thing.

http://forum.netweat...n-ramp-go-nuts/

Also, digging at others and bickering is not on - we're getting to the point where we're going to need to look at stopping some people posting in here which we don't want to do. It's down to every person posting in here to ensure that their posts are reasonable, respectful and on topic which the vast majority manage, so the minority that refuse to need to sort themselves out before we reach that stage...

[Jason M]

Just been through the GFS ensembles. There are some stonkers in there. The end of no 20 is worth a look for anyone who likes it cool. The entire country is under -12 to -14c uppers with a huge area of -20c uppers inbound. Of course only for interest.

Weekend is gradually upgrading as the scandi heights become gradually more prominant. As for ECM, who cares really as too far away to be worried about and has little support elsewhere.

Jason

[nick sussex]

Lorenzo here are a couple of links for the DGEX:

http://www.americanwx.com/raleighwx/models.html

http://www.emc.ncep.noaa.gov/mmb/mmbpll/dgexops.conus/

Unfortunately neither have a good view of Greenland or the far ne USA which would be important given the ECM/GFS/UKMO differences upstream.

Its a high resolution ETA model and works off the GFS data.

[BOMBHEADS]

the ECM shows the high in the atlantic ridging north, being squashed then dropping back south and not holding a atlantic blocking pattern. Given what i have been reading on these forums this don't look right to me.

[Bobby]

I think our Arch-nemesis is that pesky energy around Greenland/NE Canada that won't go away, it was that which scuppered the last cold spell and here it is again trying to ruin the party. The ECM would seem have trended towards the MOGREPS that Ian F mentioned which signaled an Atlantic attack but they favoured the ECM, but if the ensembles also trend that way then that certainly isn't good.

But really anything beyond day 5-6 should be considered FI, even ensembles can change a lot in this situation. But meh I have a feeling...

[fergieweather]

I haven't got time to do this, but it would be v interesting for someone to pull together some chart archives from models around same inception point of any last similar major SSW, then compare to what actually became manifested in reality as tropospheric changes materialised. Anyone up to do this little project?

[Ian Brown]

Must say I think the ECM operational has blown it tonight. The difference between the

GFS and the ECM is that the American model phases the the low in the atlantic with

the one coming out of the states allowing heights to rise to the north from the Azores

rigde. The UKMO looks as though it would do the same.

The ECM on the other hand phases the Atlantic low with the low to the south of

Iceland moving it eastwards and flattening the pattern.

The ECM got this area wrong a couple of days ago when we saw the ridge building into

Greenland and I suspect it will be wrong again.

Let's hope so CC, but it does go the way of the GFS control. If that verifies, it's goodbye January for cold. I hope we are not back in the days of whichever was the worst run for the UK was the one that would verify. The JMA is much better.

It depends on how the models handle the energy coming off the seaboard, still a case of more runs needed.