Model Output Discussion October 2012

[Roger J Smith]

NOAH bulletin ... build an ark.

[Summer Sun]

Not a bad ECM tonight after an unsettled week next week ECM shows high pressure building across a huge area of Europe into the week after as per tonight's GFS

This is one hell of a euro high

Welcome back the Azores high

[Mark Bayley]

Not a bad ECM tonight after an unsettled week next week ECM shows high pressure building across a huge area of Europe into the week after as per tonight's GFS

This is one hell of a euro high

Welcome back the Azores high

Although interestingly the PV remains weak and disorganised with blocking over the pole, more so than the GFS

GFS

http://modeles.meteo...nh-0-216.png?12

http://modeles.meteo...nh-0-240.png?12

[Gibby]

Good evening folks. I hope you all dodged the showers today. Here's a look at the 12zs from GFS, UKMO and ECM tonight.

All models show a fairly slack flow over the UK in relatively Low pressure. This allows light winds overnight frost and fog and coastal showers. This weather type continues through tomorrow and Monday with the wind flow having subtle differences in the areas affected by heavy showers. By late Monday Low pressure swings up from the SW with rain moving NE late in the day and overnight Monday. Tuesday sees a brighter day with blustery showers before the midweek period sees further low pressure swing up the Western side of the UK pushing troughs NE with heavy rain and strong winds in tow though temperatures will recover a little by midweek.

GFS then keeps the unsettled weather going as Low pressure lies close to the West of the UK with SW winds bringing milder air than of late with further rain and showers for all, heaviest in the West and North. In FI tonight the pattern gradually becomes a more mobile one as Northern blocking breaks down and High pressure develops to the South of the UK and deep low pressure takes a more traditional route North of the UK. Rain at times would occur with most of this in the North while the South sees longer drier spells in temperatures close to or somewhat above normal in the South.

The GFS Ensembles still show a very unsettled spell up and coming with rain at times.The operational was a warm outlier at the end so the milder air at the end shown there could be unlikely. However, the average of the pack indicates close to average uppers very likely with a few very mild and rather cold options on offer. Northern locations do show a lot of spread late in the run.

The Jet Stream continues to be positioned close to Southern Britain for the next week or so with the UK on the colder side of the flow, though with SW winds over the UK at ground level no real chill will be felt at the surface.

UKMO for noon on Saturday shows a Low pressure just to the West of Scotland with an unstable SW flow for all areas. Troughs in the flow will bring spells of rain and showers to all areas in temperatures close to normal.

ECM shows very unsettled weather at the same time point with rain and showers in a strong SW flow. Later in the run the winds stay SW but with High pressure building over Europe the axis of fronts move further NW with drier spells for the SE where along with the rest of Britain temperatures would be on the rise to levels near or just above normal.

In Summary tonight there is little overall change in the unsettled pattern. The main difference with time which is shared by GFS and ECM is that a pressure rise to the South and Southeast of Britain looks likely in a week or so time with less rainfall in the SE and a rise in temperatures too, above normal possibly in the SE.

[Nick F]

The 6-10 day H500 outlook from the CPC certainly indicative of a mean trough to the W and SW of the UK and ridging to the east. Bit of a turnaround from the colder outlooks of recent:

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

[johnholmes]

yes and the 8-14 outlook backs off even further from the solid looking +ve area and ridging to our north. I am not sure Nick that I agree it showed the colder outlooks as you termed it though?

If it was the Met 16-30 day outlook I also found that a bit ott in terms of its temperature ideas and the current terms seem much more likely.

[JP1972]

Bloody hell, so after all the excitement it seems there is nothing whatsoever cold to be looking forward to.

Dearie me, it seems some people need to stop hopecasting or making crazy assumptions on what MIGHT happen and start taking charts at face value to give the less knowledgable (myself) a chance to learn.

[Frosty.]

The 6-10 day H500 outlook from the CPC certainly indicative of a mean trough to the W and SW of the UK and ridging to the east. Bit of a turnaround from the colder outlooks of recent:

http://www.cpc.ncep....10day/500mb.php

Yes i'm kind of hoping it will turnaround again as some of the recent background signals have been indicating a colder trend towards the end of the month and into early november, i'm not thrilled about the euro high getting comfy and blocking our route to an early wintry spell, the same thing happened last autumn but a more watered down version of that is probably the worst case scenario. If the current trend continues, we will likely have a nw/se split with northern and western uk being mild and unsettled with the south and east eventually becoming very mild and mainly dry but at least a week of relatively cool and unsettled weather to come before that.

[johnholmes]

Bloody hell, so after all the excitement it seems there is nothing whatsoever cold to be looking forward to.

Dearie me, it seems some people need to stop hopecasting or making crazy assumptions on what MIGHt happen and start taking charts at face value to give the less knowledgable (myself) a chance to learn.

what a very very sensible post

Once again folks read what chio said about when its normal to START looking at the Stratosphere then read the post from GP which suggests looking there prior to November is a waste of time.

Maybe while we all wait for the end of October it might be a good idea to go to the winter thread and READ carefully the intro from chio. Lots and lots of helpful advice on what to look for and how to use it.

[Liam J]

Not a bad ECM tonight after an unsettled week next week ECM shows high pressure building across a huge area of Europe into the week after as per tonight's GFS

This is one hell of a euro high

Welcome back the Azores high

Certainly wouldn't be fine, dry & sunny over the UK looking at those charts. Anyway thats right at the closing stages of the output atm and is highly likely to change quite markedly.

In the meantime some very unsettled weather ahead for the upcoming week with flooding likely to become a problem in some areas.

[Nick F]

I am not sure Nick that I agree it showed the colder outlooks as you termed it though?

To tell you the truth, I haven't religiously been following the CPC outlooks, but I remember the operationals for a while were hinting at the blocking to the north shifting further west over Greenland/NW Atlantic to allow colder air south towards the UK.

Instead of the mean trough edging east, it now looks like it may loiter to the west and southwest.

[johnholmes]

I don't often use this source to quote but just for our visitors and new members, (by the way a big welcome-in spite of what may appear on some threads at times we are a pretty friendly crowd, all nuts as we spend so much time talking/arguing about the weather), but it encapsulates my views about the run into early November perfectly for the UK.

from UK Met

Anyone who pretends they can give a more realistic preview is, in my view, being a touch economical with the truth. Of course the weather may easily make a monkey out of the Met O, it would not be the first nor the last time, but then none of us is perfect.

UK Outlook for Sunday 28 Oct 2012 to Sunday 11 Nov 2012:

Indications are that through the end of October and into November mixed autumnal weather will continue to dominate across the UK. Some drier and less unsettled spells are likely, particularly across eastern and perhaps southeastern parts of the UK for a time. There will, however, also be showers or longer periods of rain affecting most parts but more especially the north and west. Overall the rainfall signal is for near normal amounts through this period. Temperatures are likely to be around average for the time of year, with some chilly nights possible with mist and fog patches developing and the risk of some wintry showers for upland parts of Scotland.

To tell you the truth, I haven't religiously been following the CPC outlooks, but I remember the operationals for a while were hinting at the blocking to the north shifting further west over Greenland/NW Atlantic to allow colder air south towards the UK.

Instead of the mean trough edging east, it now looks like it may loiter to the west and southwest.

yep Nick I'd agree with that summary

[Guest]

Bloody hell, so after all the excitement it seems there is nothing whatsoever cold to be looking forward to.

Dearie me, it seems some people need to stop hopecasting or making crazy assumptions on what MIGHT happen and start taking charts at face value to give the less knowledgable (myself) a chance to learn.

Agreed.

And the worrying thing is that some of the more experienced posters on here were the ones fuelling the colder hopes.

Not a good sign for rational posts this coming winter.

[phil nw.]

Let`s keep to the topic please.

[chionomaniac]

Agreed.

And the worrying thing is that some of the more experienced posters on here were the ones fuelling the colder hopes.

Not a good sign for rational posts this coming winter.

The thing is Bb is that currently it is cold! There is a frost forecast for England and Wales tonight. The 850's for London are 5ºC below average. The forecast for cold and blocking have come to fruition and were not nonsense! (NO snow at this time of year of course)

However we are now forecasting from this position of cold and we are now seeing a return to more average temps but with a very wet spell.

[Methuselah]

Agreed.

And the worrying thing is that some of the more experienced posters on here were the ones fuelling the colder hopes.

Not a good sign for rational posts this coming winter.

I think you might be being a wee bitty unfair to Chio and GP (and whomever I've missed); all they can do is report on what they see. And whether or not someone-else jumps to daft conclusions, this far out, is surely down to them...

[ribster]

what a very very sensible post

Once again folks read what chio said about when its normal to START looking at the Stratosphere then read the post from GP which suggests looking there prior to November is a waste of time.

Maybe while we all wait for the end of October it might be a good idea to go to the winter thread and READ carefully the intro from chio. Lots and lots of helpful advice on what to look for and how to use it.

I think it's quite the opposite, if said member wants to go and learn, there are plenty of resources for doing so, I wouldn't suggest the model thread is the best place to do it, although things can be picked up. I don't see that anyone has posted anything that hasn't been based on the output available, however far out it may have been. Nothing wrong with hypothesis, conjecture, speculation on what a setup/chart might deliver should it come to fruition. Steves posts are fantastic for example, you can feel the enthusiasm and excitement in his posts, at the same time it's quite clear what he is saying and always adds appropriate caveats.

If we are just to discuss/read about the next 5 days and what has a cat in hells chance of actually occurring, you may as well change the name of the thread!

[Zenarcher]

Things still look uncertain around 120 hours between the main 3 with how they handle the low entering the Atlantic, the UKMO and ECM look more similar though.

[Guest]

I think you might be being a wee bitty unfair to Chio and GP (and whomever I've missed); all they can do is report on what they see. And whether or not someone-else jumps to daft conclusions, this far out, is surely down to them...

The overall tone of some posts were defo fuelling hopes.

Yes it is cold for early Oct at the mo.

[johnholmes]

I wouldn't suggest the model thread is the best place to do it, although things can be picked up.

sorry to come back but to set the record straight, I did not suggest going to the model thread, I posted go to the beginning of the winter thread and read the intro?

[BLAST FROM THE PAST]

Again some posts are out of kilt. Because there's been a change looking INTO FI to mild....it's right?!!! I think folk should stick to their own advice and don't look too far ahead. An awful lot of weather to get through and yes it might be mild or cold....we'll see.

BFTP

[georgiedre]

There was some snowfall on the highest tops of snowdonia today... Some of my friends were caught in some showers..

The thing is Bb is that currently it is cold! There is a frost forecast for England and Wales tonight. The 850's for London are 5ºC below average. The forecast for cold and blocking have come to fruition and were not nonsense! (NO snow at this time of year of course)

However we are now forecasting from this position of cold and we are now seeing a return to more average temps but with a very wet spell.

[JP1972]

The overall tone of some posts were defo fuelling hopes.

Yes it is cold for early Oct at the mo.

Well my post which basically echoed yours was removed for some unknown reason.

But I totally agree that 'cold weather' (whether it floats your boat or not) was certainly being hyped up.

[SMU]

Morning All-

Still some chance of Wintry PPN into NE scotland tonight-

just looking at the ECM-

That ones been running for a few days now-

In the mid term as the depressions get downgraded to shortwaves all the systems that were modelled north & west are continually modelled further South & east - this is because they are shallow & have a weaker pull northwards against the greenland pressure belt-

Also at 48

Another chance of snow over the northern hills- ^^ in -2c upper air & SE surface winds...

So cold I would say out to day 6- especially for the North-

Post that, I have to say things do look to warm up from the south/ south east- how long is dictated by the fact that the polar blocking looks strong & for the fact that realtime sees depressions further south-

( Although the UKMO at 144 shows that things could remain cool ( not particularly cold as it defelcts the lows further South again- )

so this mildish chart will be interesting at day 7-

to see if it actually comes to fruition....& how long the mild air holds-

I do have to conceed that the thought of polar air getting across Scandi further south didnt reach as far as first thought as its squeezed & drained away west, not south & west...

S

[Frosty.]

The Gfs 00z op run shows a much milder trend beyond the next week with winds going around to the south or southeast and raising temps well into the 60's F across the south at least which would be very warm for late october, so it's a far cry from what the models were showing in FI a few days ago when it looked like an early arctic outbreak was possible. Looking at the latest ens mean, we can see how the winds slowly change direction from a general westerly which backs sw'ly and then s'ly and we lose the cooler 850's, we also lose the unsettled weather from the south as pressure shows signs of rising but northern britain tends to remain unsettled with lows never far from northwest scotland, the far north will really struggle to lose the unsettled pattern but rather than a colder late october outlook, it currently looks like a warmer and drier trend is taking shape.