Model Output Discussion

[SP1986]

"Cooling Climate" says in his post above "he cannot understand why next weeks low pressure system insists at this stage on appearing to go farther west than he thought it would", I have to say that I concur and would like the views of some of our resident experts. I know the weather will do what the weather will do but certainly the norm is for lows to move on a south-easterly track down the North Sea.

The same reason, I suspect as the low that moved SW and brought us the bitter NE'ly in December.

This is symptomatic of a -NAO and -AO oscillation, however lows going to the west of the UK is the calling card of a notable west based NAO as I see it.

[Rollo]

The same reason, I suspect as the low that moved SW and brought us the bitter NE'ly in December.

This is symptomatic of a -NAO and -AO oscillation, however lows going to the west of the UK is the calling card of a notable west based NAO as I see it.

Thanks for that Stephen,I supppose as it is all still in F1 we shall just have to wait and see,what a difference 200 miles further east would make.

[full_frontal_occlusion]

"Cooling Climate" says in his post above "he cannot understand why next weeks low pressure system insists at this stage on appearing to go farther west than he thought it would", I have to say that I concur and would like the views of some of our resident experts. I know the weather will do what the weather will do but certainly the norm is for lows to move on a south-easterly track down the North Sea.

Make an analogy with say a leaf carried downstream by the current, then look to the Jetstream and notice where all the analogous current energy is?

There is nothing to force a southerly track.

The Coriolis effect is negated by high pressure blocking to the east and once each systems angular momentum is in phase with the earths rotation,viola, stationary low pressure.

The high pressure continues filling the low with the effect of shunting the centre of mass of the low westwards.

ffO.

Edited February 10, 2010 by full_frontal_occlusion

[chionomaniac]

"Cooling Climate" says in his post above "he cannot understand why next weeks low pressure system insists at this stage on appearing to go farther west than he thought it would", I have to say that I concur and would like the views of some of our resident experts. I know the weather will do what the weather will do but certainly the norm is for lows to move on a south-easterly track down the North Sea.

I reckon that it is stratospherically driven Rollo. ( Well I would say that wouldn't I?!!! ) See latest post in strat thread.

[Cheshire Freeze]

Wow 13 posts since midnight.

Seems to me, as i said before, that this month has been a case of chasing the cold that has never been in the reliable time frame. Looks like the rest of the month will be the same, with only 18 days of winter left (in my book) this Feb is going out with a big wimper.

A very big turn around in the models (showing in the reliable) is now needed, looking at charts in FI caught us out last week in regards to this weeks downgrades and again last night and on moday people saying next week is the week to watch.

Chasing cold in FI is mad, if we cannot get any cold in the reliable nailded first.

IMBY this week has been fine dry and sunny so far with temps just below average, feels like spring in the sunshine....out of the wind mind you.

Yep the trend for next week is worrying; it could have been a snowfest if the trough wasn't projected so far west. As for FI charts, I highlighted the possibility of the retrogression idea going wrong and got told I was too negative....nah it's called common sense and realism

Edited February 10, 2010 by CreweCold

[bluearmy]

the 00z NAEFS is better than the ops wrt the trough (in line with the GEFS should nt be a surprise seeing as its part derived from this). i think we still have hope for next week but its certainly on the wrong edge of the envelope as far as we are concerned. i'm sure the models will struggle with modelling situations with strong neg zonality so we may as well stay positive for the time being!!

[Frosty.]

No real change from the GFS 06z, becoming less cold next week but very unsettled cyclonic conditions and cold enough in scotland for snow but mostly on hills, then becoming milder further into FI and remaining unsettled.

[nick sussex]

Yep the trend for next week is worrying; it could have been a snowfest if the trough wasn't projected so far west. As for FI charts, I highlighted the possibility of the retrogression idea going wrong and got told I was too negative....nah it's called common sense and realism

The models idea of the retrogression was totally correct but unfortunately its gone too far in terms of too far west. If you read Chionos post in the stratospheric thread that gives a good explanation, thats why I said too much of a good thing can be bad! reverse zonal winds are not always beneficial as they've dragged the whole pattern too far to the west, unless theres a pressure rise further east towards Svalbard and the north to edge the pattern south then its a case of the reverse zonal winds going into overdrive thwarting the cold.

[Cheshire Freeze]

The models idea of the retrogression was totally correct but unfortunately its gone too far in terms of too far west. If you read Chionos post in the stratospheric thread that gives a good explanation, thats why I said too much of a good thing can be bad! reverse zonal winds are not always beneficial as they've dragged the whole pattern too far to the west, unless theres a pressure rise further east towards Svalbard and the north to edge the pattern south then its a case of the reverse zonal winds going into overdrive thwarting the cold.

Yes Nick, annoying isn't it. Just checked the 6z control run on meteociel- not too bad for up here at all. I'd take Midlands northwards snow events next week

[swilliam]

The GEFS control run seems to offer the best hope. Although the initial low from the N is quite far West it is not too deep. When it engages with the Atlantic low the latter dominates and then moves E to the South of us. Following behind we get cold NE winds.

That needs a lot to go right though so I would not be too optimistic.

I would add that we may see charts that do not look to good for many days and then this kind of evolution can pop up at the last minute

Edited February 10, 2010 by swilliam

[Matty M]

This type of scenario could easily develop into this and the northern and Irish members remember this one very well.

Well spotted Mr Data,

One of my fond memories when i was younger, really got me into the whole weather craze.

Was a fantastic day, we probably only got around 6 inches of snow but it was the most i've ever got and it was a proper snow storm type

situation.

Whats crazy is, it occured on Pancake Tuesday, i rememeber it well! We had to cook our pancakes on the gas cooker because the electricity was gone!

And guess what day next Tuesday is?? Pancake Tuesday!

And here is the chart:

Lets hope for a repeat of 01'

[nick sussex]

Yes Nick, annoying isn't it. Just checked the 6z control run on meteociel- not too bad for up here at all. I'd take Midlands northwards snow events next week

I can understand the frustration by some members in here as generally you have so many positive factors but then up pops very strong reverse zonal winds. It's very unlikely that there will be a last minute reprieve in terms of the models shunting the whole pattern much further east so its a case of trying to find a way for the expected set up to still yield some positive results.

There are several ways this could still occur especially for more northern parts so we'll just have to see what the models do with the UK and Iberian lows.

[stewfox]

Have to say I do feel rather short changed looking at the models. What could of been 2 weeks of very wintry weather has turned into wintry showers for this week followed by cold rain next week. Just hope the output changes more favourably.

There is a tendency on here for people to keep posting charts from T168 and if they don't like them post a T240 all FI

Then the disappointment comes when la la land doesnt come off.

I know we can't mention BBC and the like forecast on a model out put discussion thread but if you look at any 'forecast' within the reliable time frame no 'beasts of the East, North or the like have ever been mentioned. Its all 5,5 ,5 ,5 ,5 type stuff etc

Peoples disappointed is over a T168 or T240 model out put not happening rather anything suggested within the reliable time frame.

Of course its disappoint for cold lovers but can we blame the models .

What is their accuracy at T168 30% T240 15% , don't know ?

We are now going to see charts for the end of Feb and no doubt will get the disappointments that follow.

For me I can live with another sub CET month with occasional snow showers.

[ScottSnow]

Yes although the trend doesn't lool good for snow at low levels. As a keen skier in Scotland, the situation looks excellent for snow over the mountains. This season has already been fantastic in Scotland and the northern England ski tows. There's already deep bases of snow and this season looks as though it could even be better than 2001 which was excellent with Scotland described as having the best snow in the northern hemisphere.

Also with pressure remaining high to our north there is still the potential there for more colder weather, although the trend isn't fantastic if high pressure is still to our north then at least theres something to build on.

Edited February 10, 2010 by Snow White

[Cheshire Freeze]

Yes although the trend doesn't lool good for snow at low levels. As a keen skier in Scotland, the situation looks excellent for snow over the mountains. This season has already been fantastic in Scotland and the northern England ski tows. There's already deep bases of snow and this season looks as though it could even be better than 2001 which was excellent with Scotland described as having the best snow in the northern hemisphere.

Looks good for snow at low levels in the north and west as this is where the more favourable dewpoints and upper air temps will be. I would imagine any heavy precipitation will bring some quite heavy snow Shropshire northwards on current charts. Obviously, any altitude will see you better off.

Edited February 10, 2010 by CreweCold

[MR EXTREMES]

i came in here this morning very optimistic now i see nothing the strat has let us down and west nao its all but failed now.

although i will be watching the news next week with scotland and ireland getting plastered along with north wales.

still i have some fond memories of this winter im now looking forward to next already lol although i dont think where be seeing charts like this for awhile after all the sun is picking up pace now,

but you never know.

the one thing the models did have some wobbles i think they just did not know what to do with shortwave over scandi and our high to the northwest,but when things settled down they picked up on a growing trend and theres noway of getting away from the current outputs,this week is the end of any really cold outputs.

Edited February 10, 2010 by badboy657

[Weathizard]

Not necessarily over yet it is, we have seen bigger turn arounds in the models in just the past week.

[MisfitDog3]

"Chasing cold in FI is mad, if we cannot get any cold in the reliable nailded first.

IMBY this week has been fine dry and sunny so far with temps just below average, feels like spring in the sunshine....out of the wind mind you."

I agree with the first statement wholeheartedly! Given the recent experience with the models (and many times in the past) can we stop trying to hang our hats on forecasts being thrown up for next week. It's very unlikely to be accurate so comment is fine on FI model runs but why let it depress or excite yourself at the stage out? Now something due to occur 72 hours ahead or so is a different kettle of fish..

As for my take on events past the weekend, I don't think the cold is in a hurry to go anywhere. I don't feel the cold being shoved into the mid-Atlantic looks sustainable as an output based on previous experience. What exactly we are going to see is anyones guess really....

As for tonight. I think areas further west of Kent are going to get more snow than currently forecast looking at the North Sea radar and wind direction.

As for it feeling like Spring?! Have you been outside? Blinkin' perishing!

[LochGarman]

although i will be watching the news next week with scotland and ireland getting plastered along with north wales.

badboy, i dont know about that. After watching the models over the last while i think anything is possible. We still really need those -8's for snow. Anything could happen here over the next few days.

It aint over till its over.

[Cloud 10]

GFS>> ECM>>

The gfs is keener to keep the trough a bit further east than the ecm which would increase the wintry potential across a greater part of the country.

However,the gfs 06z ensembles for iceland show that the operational run has higher pressure in that region than the ensemble mean,so maybe the gfs will trend towards the ecm in future runs,although i hope not!

[MR EXTREMES]

badboy, i dont know about that. After watching the models over the last while i think anything is possible. We still really need those -8's for snow. Anything could happen here over the next few days.

It aint over till its over.

its not over for ireland your in one of the best places,judging from the models anyway:drinks:.

[cooling climate]

I have to say I am still totally unconvinced of the trend of a west based -NAO.

Heights over the Arctic will drop down more into the Iceland, Svalbard area with

the lows and troughs shunted further south and east.

I know some will say this is hope casting but looking at the stratosphere charts

and the warming over the Svalbard area at the 30hpa level I think we will see a

big shift east in the models over the next three days or so.

If by the weekend this is not the case then fair enough but this is how I see the

SSW playing out for our neck of the woods.

[NorthantsSnow]

Have we been teleported to the Autumn? Bypassing summer would not be such a bad thing actually. The point I'm trying to make in a roundabout way is that the models look very unsettled right into FI.

Snowy next week? Still possible. But it's very marginal. However, the cold spell of February 2009 was very marginal and delivered a heck of a lot of snow here so I remain upbeat. Better than this damp squib of an easterly and FAR more interesting to watch!

I agree that northern areas look favoured for a pasting as things stand, particularly in places with a bit of elevation. As things stand southern England could see some snowfall as well from this, but it's a messy flow so rain turning to snow more likely here.

[The Eagle]

Well spotted Mr Data,

One of my fond memories when i was younger, really got me into the whole weather craze.

Was a fantastic day, we probably only got around 6 inches of snow but it was the most i've ever got and it was a proper snow storm type

situation.

Whats crazy is, it occured on Pancake Tuesday, i rememeber it well! We had to cook our pancakes on the gas cooker because the electricity was gone!

And guess what day next Tuesday is?? Pancake Tuesday!

And here is the chart:

Lets hope for a repeat of 01'

Been keeping a close eye on whats now within 144hrs over the last couple of days. It's not time to be shouting from the rooftops just yet but we have a very good shot at significant snow early next week in Ireland and Northern Britain probrably also. Pretty good cross model agreement atm.

Edited February 10, 2010 by The Eagle

[TEITS]

There is a tendency on here for people to keep posting charts from T168 and if they don't like them post a T240 all FI

Then the disappointment comes when la la land doesnt come off.

I know we can't mention BBC and the like forecast on a model out put discussion thread but if you look at any 'forecast' within the reliable time frame no 'beasts of the East, North or the like have ever been mentioned. Its all 5,5 ,5 ,5 ,5 type stuff etc

Lets be honest though the models have downgraded within the reliable timeframe which is why the next few days are far less wintry than what the countryfile forecast suggested on Sunday. For some reason once an E,ly moves within +96 timeframe there is a tendancy in the models to shorten and slacken the E,ly flow.

Back to the models and the GEFS control run shows what I referred to last night. I agree with Nick S, I doubt the pattern will suddenly shift much further E and our only hope is something like what the GEFS control run suggests.

I will add I have seen snow fall every day this week so maybe im just getting greedy!