Model Output Discussion October 2012

[SMU]

FWIW I think the GEM has the surpressed pattern correct-

http://modeles.meteociel.fr/modeles/gem/runs/2012101212/gemnh-0-144.png?12

I keep emphasising that Northern Europe will see some CAA developing at day 12 ( that was 5 days ago)

& within this pattern its clearly shown, its unimportant whether the whole pattern can force that cold air across norway & then south to us, but the natural progression out of the GEM at day 10 will bring it south & possibly west-

S

[Frosty.]

FWIW I think the GEM has the surpressed pattern correct-

http://modeles.meteo...nh-0-144.png?12

I keep emphasising that Northern Europe will see some CAA developing at day 12 ( that was 5 days ago)

& within this pattern its clearly shown, its unimportant whether the whole pattern can force that cold air across norway & then south to us, but the natural progression out of the GEM at day 10 will bring it south & possibly west-

S

Thanks for answering the question I asked OldMetMan

[OldMetMan]

That's a perfect undercutting low if ever I saw one. Can't say I really pay much attention to the GEM model, I always thought it was one of the cannon fodder models?

12z GFS keeps high pressure over Greenland for the entire run but also traps low pressure over us for the foreseeable

Hi Daniel, I don't look at the GEM that often also, but I have noticed it prove correct on long terms trends on a number of occasions, usually at odds with what all the other models are saying.

[MR EXTREMES]

Stuck on the fence with the model outputs today the northern blocking trend seems to be pushed back with each run.

I think depression 15 is causing all sorts of mixed signals!.

Couple more days I might be convinced of blocking but will the vortex play ball.

Million dollar question.

[Met4Cast]

Stuck on the fence with the model outputs today the northern blocking trend seems to be pushed back with each run.

I think depression 15 is causing all sorts of mixed signals!.

Couple more days I might be convinced of blocking but will the vortex play ball.

Million dollar question.

?

The blocking has already developed

[MR EXTREMES]

To be fair its not looking likely it will sustain its grip for a period of time.

With cooling strat and strengthened vortex although still early days.

Models seem like default pattern to be the outcome after a brief dryer spell.

[Radiating Dendrite]

The strat always cools at this time of year, it's October in the Northern hemisphere!

I agree it is an important piece of the jigsaw, but some on here are acting as if it is the only factor. A cold strat does not mean permanent cyclogenesis and no blocking at all.

[Gibby]

Good evening. Here is the evening look at the 00zs from GFS, UKMO and ECM. Incidentally, I am too busy to do a report tomorrow morning but will be back for the 12zs later tomorrow.

All models now show the Low for Sunday keeping far enough South to not influence the weather over the South. A showery West flow tonight and tomorrow becomes a Northerly over Sunday with showers covering all coastal counties, spreading inland through the daytime. Monday sees a brief gap between Low pressures giving most areas a bright and breezy day with the chance of a shower. Then over Tuesday and Wednesday low pressure moves in close too the West with strong winds and rain and showers spreading back to all areas by the end of wednesday.

GFS then shows low pressure centres milling around just to the West of the UK with South or SW winds and further rain at times in near average temperatures. FI tonight shows little change for a while before filling Low pressure and ridging High pressure near Southern Britain settles things down somewhat late in the run.

The GFS Ensembles show 850's near or slightly above normal with time over the UK as Low pressure sets up shop to the West of the UK promoting South or Southwest winds with periods of rain and strong winds frequently.

The Jet Stream is programmed to drive across the Atlantic close to Southern Britain and France over the coming week or so.

UKMO at noon on Thursday shows Low pressure over NW Scotland with a strong west or SW air flow over Britain with outbreaks of rain and heavy showers flowing quickly though all areas on temperatures close to the seasonal average.

ECM too shows a complex Low structure close to Western Britain with active troughs delivering some heavy rain at times everywhere in brisk winds. temperature here too are shown to be well up to the mid October average though it will feel chilly in the breeze and rain. Later in its run little change occurs with low pressure in total control over the UK.

In Summary tonight there is little overall change from previous runs with Low pressure in total domination of the weather over the UK. Heavy rain and strong winds would feature regularly over all areas through the two weeks with the West likely to bear the brunt of the rain. In all this gloom there is a positive note in the shape of the temperatures which would stay well up to average over the UK eliminating the risk of any widespread fog and frost problems.

[Zenarcher]

This evenings model comparison using the GFS, ECM, UKMO, NOGAPS, GEM and JMA.

96 hours 16th October: Most of the models show weak low pressure out in the Atlantic and over the UK. The only big difference is to the South of Greenland where the ECM, UKMO and GFS place a small low pressure system all the other models don't.

120 hours 17th October: We have two things to compare here first over at the UK all the models place a weak low pressure system to the far west of the UK giving us a bit of wet and windy weather, the GFS however goes a bit more extreme compared to the rest and shows very windy weather moving over Ireland and Scotland at the moment it lacks support. Now over to the other side of the Atlantic, all the models seem to show a low pressure system entering the Atlantic, the exact position and deepness remains a mystery for now. It's really a 2 V 2 V 2 situation, we have the GEM and UKMO place it in the same place but in terms of how deep it is there are large differences. Then we have the ECM and JMA who both agree with each and are similar on the deepness. Finally the GFS and NOGAPS are slightly similar to each other as well.

144 hours 18th October: Mixed solutions here so we have the GFS which makes this low pressure now cross the Atlantic and gaining power and the same thing happens on the NOGAPS. We then have the ECM, JMA and UKMO that seem to agree to a certain extent they have a weak low over the UK that will still bring us unsettled weather but out in the Atlantic that low pressure system seems to just die out eventually. GEM remains on it's own here as it shows the low pressure systems in the Atlantic seem pretty weak due to the Northern blocking gaining big strength.

168 hours 19th October: The ECM and JMA show weak low pressure over the UK and the blocking still in place. The GFS makes that strong low die off in the Atlantic as the blocking weakens the Atlantic. NOGAPS however just goes mental as usual and keeps this low going and places a big 950mb storm to the West of Ireland.

Overall - I believe the low pressure entering the Atlantic plays a big part in our weather for the near future with many different solutions today it's hard to pick one with confidence yet but hopefully tomorrow when it's at 96 hours the models will have a better idea of things then. The run of the day has to be the GEM as it shows the blocking looking healthy and strong at 144 hours both on it's morning and afternoon runs.

[SMU]

very poor ECM tonight- its going in the reject bin- especially after the 00z run

JMA looks like the GEM & continues out with the pattern to 192- so thats where my blended money is...

S

[BLAST FROM THE PAST]

very poor ECM tonight- its going in the reject bin- especially after the 00z run

JMA looks like the GEM & continues out with the pattern to 192- so thats where my blended money is...

S

Steve

We see the GFS and ECM slowly backing away although my timings have been last 3rd towards backend of October for colder shot. GFS deep FI never worries me and ECM still in ball park so no probs IMO. We're on the weekend now so I don't suppose we'll be any wiser until early next week.

BFTP

[Frank Trough]

very poor ECM tonight- its going in the reject bin- especially after the 00z run

JMA looks like the GEM & continues out with the pattern to 192- so thats where my blended money is...

S

seriously though, poor in what way? it's not human. That is its output, regardless of bias.

From the outputs we can all seee and view, a Euro high looks more likely than the north pole migrating to London.

also it's worth noting that it is only October 12th.

Edited October 12, 2012 by chionomaniac
Removed off topic section

[Snowy Easterlies]

http://modeles.meteo...2-10-18-0-0.png

probably been talked about already but look at this, from october 2002

fast forward to november and its all gone, http://modeles.meteo...02-11-1-0-0.png a classic case of wasted synoptics

no need to get excited or downbeat in october

Edited October 12, 2012 by Snowy Easterlies

[SMU]

seriously though, poor in what way? it's not human. That is its output, regardless of bias.

Why bother looking any further? From the outputs we can all seee and view, a Euro high looks more likely than the north pole migrating to London.

also it's worth noting that it is only October 12th.

Why is it a poor ECM because of inconsistency against its 00Z run-

S

Edited October 12, 2012 by chionomaniac
removal off reply to off topic section

[peterf]

seriously though, poor in what way? it's not human. That is its output, regardless of bias.

let's be honest - this forum is setting itself up for a MASSIVE fall from what i've read so far. The outlook in the reliable timeframe is (and has been for a while) wet, windy and dominated by low pressure gradually located to the west of the UK. Eventually this may draw up some very mild air from the south.

Why bother looking any further? From the outputs we can all seee and view, a Euro high looks more likely than the north pole migrating to London.

also it's worth noting that it is only October 12th.

Why bother looking any further?

maybe because its the model output discussion thread,is that not the idea of it?

[Snowy Easterlies]

Why bother looking any further? From the outputs we can all seee and view, a Euro high looks more likely than the north pole migrating to London.

also it's worth noting that it is only October 12th.

A euro high is always more likely to affect us than a Greenland high, as i said earlier euro highs can shift around a bit and we will still be generally in the same sort of weather, mild dry or wet, we can get a stonking Greenland high but still be under a southwesterly, so i do believe in the pharse of wasted synoptics in terms of greenie highs, cos what are the odds we get a repeat of it again in this country when they are rare to deliver the perfect set up, there are so many different synoptics our island can get from northern blocking

yes we had northern blocking this summer but we didn't constantly get raging easterlies or northeries from it did we ? we were just under slack cool air masses a lot, though i can understand if people get negative when they see GFS FI churn out a raging PV,cos thats the norm in this country in autumn and early winter esp, i don't mean to state the obvious, but we have to make the most of northern blocking when it comes around, if people like gavin cry out for a euro high in winter he will likely get his wish as it is a common synoptic

Edited October 12, 2012 by Snowy Easterlies

[Geordiesnow]

seriously though, poor in what way? it's not human. That is its output, regardless of bias.

The outlook in the reliable timeframe is (and has been for a while) wet, windy and dominated by low pressure gradually located to the west of the UK. Eventually this may draw up some very mild air from the south.

Why bother looking any further? From the outputs we can all seee and view, a Euro high looks more likely than the north pole migrating to London.

also it's worth noting that it is only October 12th.

Don't normally rate posts but I have this one, despite all the blocking, I have seen little evidence of any sustained cold shot heading our way and it does look like the Atlantic is going to kick up a gear or two.

I always find the ECM tends to over-do blocking and always shows the most "clean" set up whereas the GFS is tends to be more messy but it has to be said, the GFS looks more consistent with the outlook for our shores at least.

And indeed, its only October 12th, lets enjoy some autumnal weather at least and a spell of wet and windy weather won't go a amiss with me.

Edited October 12, 2012 by chionomaniac

[chionomaniac]

Keep it friendly guys please - I know when a thread can go pear shaped......

[Snowy Easterlies]

Don't normally rate posts but I have this one, despite all the blocking, I have seen little evidence of any sustained cold shot heading our way and it does look like the Atlantic is going to kick up a gear or two.

I always find the ECM tends to over-do blocking and always shows the most "clean" set up whereas the GFS is tends to be more messy but it has to be said, the GFS looks more consistent with the outlook for our shores at least.

And indeed, its only October 12th, lets enjoy some autumnal weather at least and a spell of wet and windy weather won't go a amiss with me.

Agree a lot of people are harping on about the blocking now, but if this was winter would we be getting any snow? i doubt it, we will be under a southwesterly next week even with copious northern blocking

[SMU]

Don't normally rate posts but I have this one, despite all the blocking, I have seen little evidence of any sustained cold shot heading our way and it does look like the Atlantic is going to kick up a gear or two.

I always find the ECM tends to over-do blocking and always shows the most "clean" set up whereas the GFS is tends to be more messy but it has to be said, the GFS looks more consistent with the outlook for our shores at least.

And indeed, its only October 12th, lets enjoy some autumnal weather at least and a spell of wet and windy weather won't go a amiss with me.

maybe you consider the fact that seeing as everyone keeps reminding us of the date they fail to recognise that the subsequent air masses are at a level relevent to October the 12th-

But we havent seen any cold weather yet??

Why is the hadley CET 1.4c below the norm then?

I dont think anyone has said its going to freezing cold- just cold relative to the norm-

S

[Geordiesnow]

Agree a lot of people are harping on about the blocking now, but if this was winter would we be getting any snow? i doubt it, we will be under a southwesterly next week even with copious northern blocking

We do get a brief NE'ly on Sunday but its weak and fills in very quickly. Its hard to say if in a few months time if a similar set up came along, will it be more potent because obviously the uppers will be much colder therefore the set up could turn out differently in respect that if you have a large slice of PV over Scandi then no doubt any warmer airmasses will find it harder to break it down, a little difficult to explain.

maybe you consider the fact that seeing as everyone keeps reminding us of the date they fail to recognise that the subsequent air masses are at a level relevent to October the 12th-

But we havent seen any cold weather yet??

Why is the hadley CET 1.4c below the norm then?

I dont think anyone has said its going to freezing cold- just cold relative to the norm-

S

That's fair enough but I havant seen much output to suggest on a cold lovers POV, there's too much to get excited about and I think for those who are new to the models need to realise that.

However as I said a few days or so ago back, the northern hemisphere set up has got interesting on a pressure pattern POV, its unusual too see northern blocking and the PV hit for 6 in October and it was interesting too see how the models will handle it. Sadly it all gone a bit messy especially with the GFS but I think this model has handled what the weather may be like for us much better than the ECM which suggested the blocking may effect our weather more than the models are showing now.

[chionomaniac]

Just to add some perspective to the current pattern.

Firstly, the 850 temps are currently forecast to be around 5ºC below average for the next couple of days and are not forecast to reach around average until around T+120.

That is five days away and all models have kept northern blocking in that time.

From there, there will be a number of options, but it is worth noting that there is a large spread of options with neither northern blocking or a stronger mobile jet stream pattern more indicated at this point.

In recent years we have seen that once northern blocking has occurred the model have quite often programmed and then delayed it's demise.

Other than snow on Scottish hills I have not seen snow touted as being on the cards for any lowland areas in the UK even though a 5ºC below average 850 is significant.

Moving on into a less reliable time frame there are suggestions that the MJO may move on to phase 1 - the likelihood from this is a reduction in Northern blocking.

However, the NH blocking forecasts still indicate strong northern blocking

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/blocking/real_time_nh/mrf3.nh.shtml

Let's see what the pub run can bring!

[bluearmy]

However, the NH blocking forecasts still indicate strong northern blocking

http://www.cpc.ncep....h/mrf3.nh.shtml

Let's see what the pub run can bring!

but thats derived from one gfs suite (00z). not clear if its via the op or ens. note that cpc still have low confidence in the fi model output.

Edited October 12, 2012 by bluearmy

[BLAST FROM THE PAST]

Pub run looking interesting? will it revert to more blocked outlook? Also 25 years ago we had the great October 87 storm.....we have a potential deep depression hitting us around the anniversary

BFTP

[chionomaniac]

One chart worth showing tonight.

Just where is the jet stream heading?

Edited October 12, 2012 by chionomaniac