The Seasonal Forecast Thread

[John Badrick]

So because we have had a good Old British summer what about put it out there and say we are going to have a good Old British winter. Got a feeling the seasons are getting back to norm.my prediction then..progressively cooler... November will be cooler then turn colder towards the end of the month, December will be cold, January will be cold, February will be...errm cold, March 2014 will start of cold and get progressively warmer, April 2014 will be milder with showers...good old British weather, back to the old days

Edited October 19, 2013 by John Badrick

[BLAST FROM THE PAST]

Well no dressing it up a month of two distinct halves I think....notable cold, very windy and very wet 1st 3rd/half with jetstream well south / blocked and then shifting north with a 'Euro HP' developing and 'classic zoneality.  Overall mild to very mild CET of 8 - 9c.  First part to be affected by my thoughts of very active/impactual LP/s on southerly track end of Oct and carrying on into early Nov.  A Northern block that may be in place to break/ give way as traditional classic zoneality sets in for second half....... GIN corridor LPs as jet heads north  with a SW'ly regime dominating.....and may do for some time 

 

BFTP

Edited October 20, 2013 by BLAST FROM THE PAST

[Catacol]

There seems to be an awful lot of pessimism floating around about this coming winter - if it is cold you like, that is. However I dont understand it. Surely it is obvious that it is much too early to tell what is going to happen, and while analogue years and projections of possible El Ninos or collapsing El Nino to ENSO neutral, or tripole possibilities (or not) and extensive siberian snow cover... or not because of blow torch October... or solar activity rising or perhaps falling.... or possible SSW in late winter... or not....  - -  is all very interesting that fact of the matter is that there are too many variables involved in our winter to pin them all down, and any projection at this range is a guess at best. I have come to understand factors which in hindsight can be seen to have caused a particular weather type, but the problem is that it is nearly always a hindsight analysis. The best forecaster on here was GP, but even he got December last year wrong in terms of detail at quite short range, and some of his summer forecasting has been off target.

 

Of interest however is that the 3 warmest Octobers on record have all come since 2000. Not sure whether this is pure fluke or symptomatic of circulation changes that are ongoing at present - but it would seem that the mild temperatures we are currently experiencing are not out of kilter. 

 

I think Chio's dead pan answer pointing to another 4 weeks before making any clear judgement is wise. Currently all we know is that the vortex is strengthening and our more meridional jet in the 21st century is bringing very mild air with it as atlantic weather fires up. 

[Catacol]

But while I'm musing over seasonal patterns, and possible increases in extreme weather - has anyone noticed what an interesting decade the 1940s was for CET anomalies? Statistically across 365 years of CET record we might expect the 1940s to be present in the warmest 10 2 or 3 times, but in a 7 year period this is quite impressive:

 

Feb 45 - 6th warmest on record

Mar 48 - 6th warmest on record

Apr 43 - 4th warmest on record

Apr 44 - 8th warmest on record

May 47 - 8th warmest on record

Aug 47 - 4th warmest on record

Sept 49 - 3rd warmest on record

 

I wonder what weather people were saying back then?

[BLAST FROM THE PAST]

Well no dressing it up a month of two distinct halves I think....notable cold, very windy and very wet 1st 3rd/half with jetstream well south / blocked and then shifting north with a 'Euro HP' developing and 'classic zoneality.  Overall mild to very mild CET of 8 - 9c.  First part to be affected by my thoughts of very active/impactual LP/s on southerly track end of Oct and carrying on into early Nov.  A Northern block that may be in place to break/ give way as traditional classic zoneality sets in for second half....... GIN corridor LPs as jet heads north  with a SW'ly regime dominating.....and may do for some time 

 

BFTP

 

This is similar to what I see for early Nov.

 

 

And sort of this latter half of Nov.

 

BFTP

Edited October 24, 2013 by BLAST FROM THE PAST

[Catacol]

 

This is similar to what I see for early Nov.

 

 

And sort of this latter half of Nov.

 

BFTP

 

Pretty closely fits the Met Office 16 - 30 dayer. The Met are gettng quite good on those monthly forecasts now.

 

I cant quite shake the feeling that RJS has this winter wrong - despite the fact I am a big fan of his. If I read Roger right he sees a Euro high this year with the jet riding over the top and only the occasional toppler. But weather watching of the last 6 years or so - and including this year too - just doesnt fit that pattern. Gavin's last video was interesting, pointing out some ocean patterns that may actually encourage more of a mid atlantic blocking pattern this year, and that would result in average rather than mild conditions. If the NA tripole pattern does emerge then the chances of a -NAO certainly increase. I also look at Siberian snow cover on top of the fast refreeze of the arctic and cant shake the sense that the ongoing pattern shift of the last few years is still exactly that - ongoing. Not too many voices out there explaining with any confidence why the ice and snow have grown so quickly, and we know there is a correlation with the upstream strength and intensity of the Siberian high on that back of this. Perhaps the sun will wake up and throw a spanner in the works, but to my very amateur eye I keep seeing low pressure and not high pressure over the continent with blocking highs to our NE and NW waxing and waning as the winter develops.

 

I'll also mention that the Glosea4 500hPa pressure patterns in the current Oct run change radically when comparing 2 - 4 months with 3 - 5. They suggest to me that once November is out of the way the signal for blocking to the north is definitely there, with a positive anomaly over both Greenland and Russia. I dont quite understand some of those maps and how they relate with each other - the temperature anomaly charts seem to suggest raging warmth all over the place to our north, but the pressure patterns look favourable to me for a feed from the north rather than the south.

 

Add the Glosea4 850 anomaly charts pointing to colder than average 850s over much of the UK and France and I'm not seeing a mild winter.

 

Having said all that my knowledge and understanding is dwarfed by many on here, so I wouldnt dream of risking issuing a seasonal forecast... but if I were forced to put my money on something I would go for a winter with a good deal of northerly influence. At least 1 or 2 shots from the NE likely especially in the latter weeks when the atlantic is at its weakest, but plenty of NW influence too.

 

And if the theory put out on American Weather regarding the possible early warming effect of ozone build up and typhoon track turns out to be anything like accurate we have the vague chance of an early buckling of the vortex. Ha - I wonder whether Roger's very warm mid Dec call might end up tying in with that exactly with the buckling of the vortex putting us on the warm side of a meridional pattern at that stage... If so then then yet more evidence of the worthiness of his methods even if my own gut is telling me that mild overall is not what will happen. 

Edited October 24, 2013 by Catacol_Highlander

[BornFromTheVoid]

I've decided to seek suggestions for other criteria that I could use when developing the composite maps. Perhaps turn my forecasts into something of a crowd forecast.

The criteria I consider are the previous 6-9 months trends, mean and variance in the

AO

NAO

PDO

AMO

QBO

Snow Cover

Sea Ice

11 Year Sunspot Variation

 

I've been toying with the idea of adding something for short term solar activity, but cannot find much in the way of peer reviewed studies to support it's impact on our weather. If anyone has any papers on the subject I'd appreciate a link.

Also, if anyone has any suggestions for other criteria I could take into account, do suggest some!

 

I've been trying out adding different weightings for different seasons to the criteria I consider too, such as increasing the weighting for sea ice and snow cover in winter, and generally having a reduced weighting for the AO and NAO as they can often be the result of some of the other criteria used.

 

As this winter is likely to be ENSO neutral, another thing I'm considering, is after all the years have been matched up with the criteria mentioned above (so that each year since 1951 has a certain number of matching criteria with this year, e.g., say 1959 has similar AO, NAO, Snow Cover, Solar, AMO and PDO to this year, but dissimilar ENSO, sea ice, and QBO, so has 6/9 matching) the years with strong ENSO events would have their weightings further reduced (so 1959, if it had a strong El Nino, would be reduced from 6/9 to 5/9, and so might appear in the composite map once instead of twice).

 

Anywho, suggestions are welcome! 

[chionomaniac]

The more criteria you use the smaller the sample size becomes. You will probably end up with a composite of just 1 day, BFTV!

[BornFromTheVoid]

The more criteria you use the smaller the sample size becomes. You will probably end up with a composite of just 1 day, BFTV!

 

Well, I suppose I should clarify that any suggested criteria to add should have records going back at least a few decades! Not every criteria has to match up though, so for the composite maps I might add a year once that had 5/9 matches, then twice for 6/9, and so on.

[summer blizzard]

I've decided to seek suggestions for other criteria that I could use when developing the composite maps. Perhaps turn my forecasts into something of a crowd forecast.

The criteria I consider are the previous 6-9 months trends, mean and variance in the

AO

NAO

PDO

AMO

QBO

Snow Cover

Sea Ice

11 Year Sunspot Variation

 

I've been toying with the idea of adding something for short term solar activity, but cannot find much in the way of peer reviewed studies to support it's impact on our weather. If anyone has any papers on the subject I'd appreciate a link.

Also, if anyone has any suggestions for other criteria I could take into account, do suggest some!

 

I've been trying out adding different weightings for different seasons to the criteria I consider too, such as increasing the weighting for sea ice and snow cover in winter, and generally having a reduced weighting for the AO and NAO as they can often be the result of some of the other criteria used.

 

As this winter is likely to be ENSO neutral, another thing I'm considering, is after all the years have been matched up with the criteria mentioned above (so that each year since 1951 has a certain number of matching criteria with this year, e.g., say 1959 has similar AO, NAO, Snow Cover, Solar, AMO and PDO to this year, but dissimilar ENSO, sea ice, and QBO, so has 6/9 matching) the years with strong ENSO events would have their weightings further reduced (so 1959, if it had a strong El Nino, would be reduced from 6/9 to 5/9, and so might appear in the composite map once instead of twice).

 

Anywho, suggestions are welcome! 

 

Personally i would remove the NAO and bring in GLAAM. I'd also use the MEI for ENSO.

[Nol de Ruiter]

Europe Winter Forecast: Warmer, Less Snow for Most Areas

 

 

http://www.accuweather.com/en/weather-news/europe-winter-forecast-warmer/19131940

 

 

[Interitus]

Personally i would remove the NAO

 

Why?

[BLAST FROM THE PAST]

Why?

Its a response not a driver

 

BFTP

[Roger J Smith]

People were asking in the CET thread if my even higher call for NOV (over there I went up from 7.7 to 9.7) is any sort of indication of changed thinking about the core of the winter. As that was already 2/3 mild and 1/3 cold with December particularly mild, I would say probably no change there, and my CET forecasts are sometimes driven a bit by game theory considerations, given that I'm in the chase pack and at this point you might want to separate yourself from that pack if you want to create a chance of gaining ground. You could also go the other way, in this case, towards near normal as almost everyone concerned seems to feel that 6 is the base for November CET and 7-8 the most likely range. So I wouldn't read much into it, if there were money involved I would likely be saying maybe 8.5. The 9.7 is driven a bit by the score risk-reward paradigm. Also I keep seeing these Pacific lows go past me about 800 miles to the north and then not dropping southeast very far which tends to support a long-duration arctic vortex not able to displace itself very far from the Canadian side of the pole. If that's the case, it's not likely to turn cold in Europe and it could stay cold in eastern Canada for long periods.

 

So at this point, not seeing any real change in outlook, there could be one or two modest cold spells later this month if the jet relaxes for a while, but I am expecting mostly mild westerly type patterns and some amplification at times until about New Years. After that, some chances probably develop for real winter weather to develop for a few days here and there, and as I've been saying, while the numbers may average quite mild, it only takes one good event to make a winter somewhat memorable, and as the coldest signal is in mid-January that timing does remind me of Jan 1987 enough that I haven't given up hope for the winter. But at this point I would be hoping more for quality than quantity.  

 

 

[UV-RAY]

As much as I respect your methodology Roger I just can't see how you can forecast for specific times, as I remember your forecast for last summer and winter where for shades of 76 and a February 47 type month. I follow your forecasts with great interest but coming out with such comments makes you look silly and are doing you more harm than good. I rate your methodology highly just not your headline grabbing snippets.

Edited November 1, 2013 by Sceptical Inquirer

[Interitus]

Its a response not a driver

 

BFTP

 

*ALL* teleconnections are responses!

The NAO represents the dominant climate pattern for the North Atlantic region so encapsulates and aggregates many of the minor feedbacks from other more tenuous connections. Thus it is absolutely incorrect to say that it cannot be considered a driver, as a massive of body of research literature can attest to.

It has extensive datasets, measured across varying modes of action, for example this paper examines at least 10 different forms of NAO while introducing another -

http://ljp.lasg.ac.cn/dct/attach/Y2xiOmNsYjpwZGY6MjE2

 

But you would have the AO?

Though the NAO is related to AO they have differing trends, particularly in winter as shown in this graph of NOAA daily averages-

 

[sebastiaan1973]

OPI 2013 is around 1.65


For a period of almost 30 years, this represents an excellent correlation. Last time the OPI was as high as this year, was in 1992.

http://www.americanwx.com/bb/index.php/topic/41379-october-pattern-index-predicting-winter-ao-from-october-with-90-accuracy/page-2
http://www.centrometeotoscana.it/forum/index.php?topic=7356.0

http://www.centrometeotoscana.it/forum/index.php?topic=7364.msg

Edited November 2, 2013 by sebastiaan1973

[Don]

Thanks for the response Roger.  Interesting that you see a signal that reminds you of January 1987.  I think most on here would take that even if it meant the rest of Winter was average to mild!

[Snowyowl9]

 I remember your forecast for last summer and winter where for shades of 76 and a February 47 type month.

Better late than never this summer certainly been a 1976 type and we had a 1947 type march/first half of april   Jan wasn`t bad either

[UV-RAY]

Better late than never this summer certainly been a 1976 type and we had a 1947 type march/first half of april   Jan wasn`t bad either

it was the summer of 2012 Snowyowl, but yeah Roger wasn't far out with March. That's my point though it's far better talking about specific weather types expected at certain times rather than dates.

[LomondSnowstorm]

My winter forecast:

http://forum.netweather.tv/blog/237/entry-4684-lomond-snowstorms-epic-novel-winter-forecast-201314/

[Winter wonder]

Any good volcanic activity could make its way into the criteria list. No major single events to speak of recently but increased activity globally. Did Icelandic eruption slightly cool region in 2010? I shall keep an eye on levels and density of Noctilucent clouds over the Arctic in summer 2014 and see if there is a correlation between that and the rate of summer ice loss. 2013 saw record levels.  By the way I don't understand all of the scientific phases I read here but I like to I think I have good weather instincts. 

[sebastiaan1973]

http://www.centrometeotoscana.it/forum/index.php?topic=7473.0

The guys behind the OPI have made their forecast for winter 2014. Please use google translate if you don't read good Italian.

[summer blizzard]

Any good volcanic activity could make its way into the criteria list. No major single events to speak of recently but increased activity globally. Did Icelandic eruption slightly cool region in 2010? I shall keep an eye on levels and density of Noctilucent clouds over the Arctic in summer 2014 and see if there is a correlation between that and the rate of summer ice loss. 2013 saw record levels.  By the way I don't understand all of the scientific phases I read here but I like to I think I have good weather instincts. 

 

You need something like VEI6 for enough of an impact, that's not likely to happen and the 2010 eruption had no discernible effect.

[lorenzo]

http://www.centrometeotoscana.it/forum/index.php?topic=7473.0

The guys behind the OPI have made their forecast for winter 2014. Please use google translate if you don't read good Italian.

 

Interesting read Sebastiaan, thanks for the link. One wonders if these guys are really onto something, I guess the million dollar question is what computation is being used in their 'Telemappa' software to create the 'axis' line, the one visible Labrador > Siberia on the October composite.

 

Approfondiemento means deepening if anyone is wondering about the lines on the GPH plot. Indicating the vortex strengthening. Google translate doesn't translate the images !

 

A very specific forecast on what the expect the vortex to do, well worth a read, I suspect this forecast will be under close inspection as it takes the Cohen SAI work onto the next level.

 

re: earlier, Regards to NAO, would definitely keep a look out for that and put it in the mix.