Autumn And Winter Lrfs

[Damien]

Oh dear.

http://www.btinternet.com/~highdown/

The worst pattern possible. Warm September followed by a cooler, wetter October. A warm August and a very wet November are also forecast interestingly though. But I still smell doom in the air for this winter.

[summer blizzard]

Just a quick update, but there are some interesting developments on the winter front...

1) QBO is now returning to a neutral mode, this is a very good sign for winter as it indicates a weak Pacific Jet Stream

2) MEI value has now broken 0.5, this means that there is a weak El Nino, assuming the value stays between 0.5 and 1, this coreelates to a negative NAO during winter

Good times ahead...

In regards to the MEI value, there are three anologues since 1950 which have a similar pattern to the past three months (May and June neutral, July weak El Nino) these are:

1951

1976

1977

1951 observed a weak EL Nino during Autum and a neutral El Nino during winter.

1976 observed a weak EL Nino during Autumn and a neutral El Nino during winter.

1977 observed a weak El Nino during Autumn and winter.

Of those three anologues, there is a strong signal for a negative NAO during December and February.

When it comes to the QBO, i looked for anologues with May, June and July all having a value above 10 with the QBO value peaking in June, the anologues are:

1985

1990

1995

The thing which i find most pleasing is that all of those anologues featured two below average winter months.

[kippure]

Is it possible to summarise what a likely shift in pattern change could be forcast for the coming months. Another autumn/winter domainated by High pressure. Or an increase in the jet pushing lows in from the atlantic.

Is it possible for more northerly outbreaks, this is just what ive picked up on, a early emerging pattern in the embro stage of a cool N NW out break every 7 -10 days over the whole of the british isles and eastern europe. Is it a sign of our future weather this autumn for example?

[Damien]

Even though these charts are complete crap, I find the latest local thoughts from ECPC very encouraging, as they... well, see for yourself:

August:

(certainly backs up the latest thoughts from the GFS et al.)

September:

A nice cooler than average September for almost all of the UK. B)

October:

Nice and the mildest month of the three B) - if just marginally so. Compare with the last (July 21-ish) IRI update.

November:

(No words needed. Unlikely but at least there. )

I now want this to be right , although a mild winter may well be at the end of it, as NCEP.

[The Enforcer]

These charts are hopeless.

Has the penny finally dropped?

For the record, consistency:

http://ecpc.ucsd.edu/projects/GSM_home_dat....con_global.gif

The forecast has completely reversed. And this is effectively the 'autumn' forecast. If it can't get a handle on autumn, then it is not going to get a handle on winter.

[Damien]

Has the penny finally dropped?

I meant in terms of how those new longer range charts - on both the diagrams - are handling the current patterns/pressure patterns/SSTs (very important) /etc.. Look at today's August - Central England is below normal again. Just yesterday it was mild and above average. Today it is cooler again. On all those August charts over the last few days the air/sea air has been mild or very mild around the shores of the Southern British Isles. Yet the Central England area still comes out as cold (why can't this happen in the winter?). In itself, if it is now starting to struggle with the ultra-short-range temporal charts, what hope does it have with the longer-range charts, that pleasing-looking cooler September to be followed by a slightly above average October notwithstanding?

The key is that the winter forecast was not struggling around the May-early June period, when the Met Office NAO forecast is made, and the SSTs were (mostly - and in this case ultimately) in favour of the cold or colder than average winter that the NOAA then forecasted. So all hope is certainly not lost. B)

[summer blizzard]

I just thought i would let you all know that my full Autumn forecast will be released on the 10th August.

[Thundery wintry showers]

I still don't place a lot of trust in those graphs.

The Met Office was widely praised for getting the winter 2005/06 forecast reasonably accurate, from 3 months out, but they didn't go into the same detail as these outputs. Also, these outputs are going out several months ahead. If it's difficult for the MetO to do accurate seasonal forecasts for Britain 3 months ahead, I struggle to see how a model could possibly predict accurately for a whole region 6 months ahead.

[kippure]

I just thought i would let you all know that my full Autumn forecast will be released on the 10th August.

Any cold periods? B)

[Damien]

Any cold periods? B)

Yeah, give us just a *little* sneak preview. Say, of mid-November(?). (NOT late Nov. - I view that as a significant period for whatever winter we may get.)

Ian, you make some good points, but I am just saying that the NOAA charts are much less reliable now than they were when they were forecasting a cold winter, or a typical "light yellow" winter in previous years - just look at some of those later charts: they are simply implausible! The ultra-mild winter charts at present are only very plausible/likely because of all the mild winters we have had since 1991, and in particular since Mr. Blair came to power.

[Guest Viking141]

Yeah, give us just a *little* sneak preview. Say, of mid-November(?). (NOT late Nov. - I view that as a significant period for whatever winter we may get.)

Ian, you make some good points, but I am just saying that the NOAA charts are much less reliable now than they were when they were forecasting a cold winter, or a typical "light yellow" winter in previous years - just look at some of those later charts: they are simply implausible! The ultra-mild winter charts at present are only very plausible/likely because of all the mild winters we have had since 1991, and in particular since Mr. Blair came to power.

LOL! That would be all the hot air then!!

:lol: :lol: :lol:

[summer blizzard]

Yeah, give us just a *little* sneak preview.

Autumn as whole will be cooler and wetter than average.

Very wet October.

Very cold November.

[Damien]

Autumn as whole will be cooler and wetter than average.

Very wet October.

Very cold November.

A very audacious forecast! Can't wait to hear the rest of it! :lol:

More than what I was asking for but still thanks. :lol:

I would love to hear how this could be possible with global warming dooming future generations to furnace-like conditions, but I look forward to reading it later this week. :lol:

[summer blizzard]

Firstly, I will start by saying that this is my first attempt at a very detailed seasonal forecast, while I consider my other forecasts satisfactory, I believe that this method maybe more reliable.

I am going to base this forecast on observed teleconnection patterns and analogues in order to make a seasonal forecast.

ftp://ftp.cpc.ncep.noaa.gov/wd52dg/data/i...s/tele_index.nh

http://www.cpc.noaa.gov/data/indices/qbo.u30.index

As you can see, including the QBO, there are nine main teleconnection patterns to take into account because the Tropical/ Northern Hemisphere and Pacific transition patterns are not leading modes during the autumn months. I will also not be including the Polar Eurasian Pattern, the East Pacific/North America pattern or the East Atlantic Pattern because they have not been leading modes during this summer. That leaves the following teleconnection patterns to consider in my autumn forecast:

QBO

NAO

WP

PNA

SCA

EA/WR

The QBO played a major part in the latter half of 2005 and was strongly negative which played a major part in displacing the Azores High into Europe by effectively displacing pressure systems eastward, with a westerly QBO playing quite a strong part during the summer, this alone would favour a European Trough over a European Ridge during the Autumn.

The West Pacific Oscillation did not play a strong part during the spring however it has played a strong part this summer in maintaining a Trough in the western Pacific, this alone could cause a stronger Jet Stream during early autumn due to the continent retaining a lot of heat and causing a fairly large thermal gradient however as the continent cools, the thermal gradient should weaken, for the British Isles, that would favour early Autumn ridge and a late Autumn Trough over Europe.

During this summer, the PNA has played a major part in maintaining a negative PNA, which is characteristic of a trough/ridge pattern over the United States of America; this is serving to encourage a northerly tracking Jet Stream and another downstream ridge over Europe, favoring a warm autumn for the British Isles.

The NAO has played a major part throughout 2006 however there has being no clear signal towards a negative or positive NAO, using the NAO alone, I would say that the chances of a mild/cold Autumn are equal.

The East Atlantic/Western Russia pattern has played a major part this summer in maintaining a trough to the west of the British Isles, I would expect this to continue, encouraging a more unsettled pattern during autumn.

The Scandinavian pattern has played a moderate part during this summer however it has been forced by other teleconnection patterns and has actually been negative during the summer, if this were to continue I would favour a European Trough.

When we add all these factors together, I think that the chances are that September will be unsettled but above average, while October and November are both unsettled and below average, this is because teleconnection patterns strongly favour a European Trough during late Autumn, during early Autumn, teleconnection patterns are fairly balanced towards heat or cold.

THESE ARE ONLY MY PRELIMINARY THOUGHTS, MY FULL AUTUMN FORECAST WILL BE RELAEASED DURING MID AUGUST.

Damien, i also refer you to this post.

[kippure]

A very audacious forecast! Can't wait to hear the rest of it!

More than what I was asking for but still thanks.

I would love to hear how this could be possible with global warming dooming future generations to furnace-like conditions, but I look forward to reading it later this week.

Check out the lastest disscussion on global warming in Enviroment Change and why "furnace-like-conditions" might not be whats in store.

[BLAST FROM THE PAST]

Autumn as whole will be cooler and wetter than average.

Very wet October.

Very cold November.

SB

I look forward to it. I like the November bit, I think that there will be a very quick switch to cold conditions during November. I am differing in Oct as I expect it to be warm, especially first half.

BFTP

[Weather Man]

SB

I look forward to it. I like the November bit, I think that there will be a very quick switch to cold conditions during November. I am differing in Oct as I expect it to be warm, especially first half.

BFTP

I think that u will have very cold october and gradual warming in november to be around average or less abit than average, and a very warm and wet end of december and january ...

[Guest Viking141]

Speaking of winter forecasts when does the METO one come out? I know its September but what date?

[Damien]

Speaking of winter forecasts when does the METO one come out? I know its September but what date?

We managed to "find" the forecast early last year when the forecast appeared in an article in one of the Sunday tabloids, mentioning that the Met Office had given a statement about it to a union representative. Within that same week it made the headlines; Paul Hudson talking about it on Look North news, and later apologising for its incorrectness circa late January.

Last year the final winter forecast was published around the very end of November. Incidentally Metcheck have historically given their first winter thoughts around now so keep watching that site; and John Kettley's. I just have a *feeling*....

Today's NOAA long-ranger is very chaotic by the way; except for that exceptionally mild winter at the end. :lol:

[Guest Viking141]

OK cheers. Whats the URL for John Kettleys site?

:lol:

Incidentally, just spoke to Andrew Bond at Metcheck - they are not doing seasonal forecasts anymore :lol:

Edited August 7, 2006 by Viking141

[Damien]

OK cheers. Whats the URL for John Kettleys site?

John Kettley's main site, which I still go to, is:

http://www.BritishWeatherServices.co.uk/

but his main-international forecast site is now:

http://www.SixthSenseWeather.com/

Keep an eye on the LRF page on the latter - though the hurricane forecast has gone badly wrong for this season.

Incidentally, just spoke to Andrew Bond at Metcheck - they are not doing seasonal forecasts anymore :o

Yes, I've heard that before. Maybe that's what Steve Murr meant by "my winter forecast with (Metcheck's?) Matt Hugo", which we will no doubt get soon.

[SMU]

John Kettley's main site, which I still go to, is:

http://www.BritishWeatherServices.co.uk/

but his main-international forecast site is now:

http://www.SixthSenseWeather.com/

Keep an eye on the LRF page on the latter - though the hurricane forecast has gone badly wrong for this season. :o

Yes, I've heard that before. Maybe that's what Steve Murr meant by "my winter forecast with (Metcheck's?) Matt Hugo", which we will no doubt get soon.

Yes Damien I will be working with Matt on this years forecast-

S

[Guest Viking141]

After all the hype of a couple of years ago, Metcheck didn't really seem interested in a winter forecast last year.

They based their forecast largely on lack of Eurasian snow cover and therefore concluded that blocking was unlikely. :o

So why no longer any interest? Is this because they got their fingers badly burned a couple of years ago?

Damien - cheers for the links.

Edited August 8, 2006 by Viking141

[The PIT]

Did the unmentionable ever get a long range forecast nearly correct???

Edited August 8, 2006 by The PIT

[Damien]

After all the hype of a couple of years ago, Metcheck didn't really seem interested in a winter forecast last year.

They based their forecast largely on lack of Eurasian snow cover and therefore concluded that blocking was unlikely.

They based the inaccurate November-January 2004/05 winter forecast on above average frequency of polar cells among other factors, such as satellite data from the NOAA.

They relied heavily on the NCEP long-range data for that year too I believe. Even more embarrassing was that the period February-March 2005 was forecast to be above average. B) I remember Andrew saying somewhere that this was why they ditched the NCEP.

But Metcheck is a great site and I find its 14 day forecasts very accurate and reliable.

So why no longer any interest? Is this because they got their fingers badly burned a couple of years ago?

Yes - very. They did what the Met Office did in 2004/05.

Did the unmentionable ever get a long range forecast nearly correct???

Who might that be then?