The Seasonal Forecast Thread

[Steve C]

Thanks for your thoughts. Not sure I'd look forward to the last sentence, if it was to come to fruition.

[marksiwnc]

Just a quick question roger. What I thought was quite evident this year is the amount of low pressures coming along the south coast. Do you think that this might continue into winter and a chance of storms coming in at a west to east along the south bringing colder weather further north??

[BLAST FROM THE PAST]

Thanks Roger

That is looking pretty much generally how I see it, which is particularly interesting as we have had no collaboration this year.  I'll be releasing mine 'officially' in early Nov after fully reviewing the OPI and some other little bits I look at BUT it overall will read closely to what I have written in Sept and what you have outlined so well.   I'll try and pinpoint a couple or three 'notable' events too.

Again with a jetstream I see on an overall NW/SE axis very close to west of UK 'overall variability' is the choice term as this in itself suggests that arctic airmases and tropical maritime arimasses will both have their time over us, which was completely absent last year.

 

regards

 

BFTP

[Daniel*]

Thanks for your thoughts. Not sure I'd look forward to the last sentence, if it was to come to fruition.

There's a thrill inside me that hopes that it does come to fruitition. Beats being under a Bartlett high, just hope no lives are lost - great forecast I anticipate a battleground situations. Edited October 23, 2014 by Daniel*

[Don]

Thanks Roger as always for a detailed account of how you see this Winter shaping up.

 

Looks like a rather messy Winter and although it carries lots of interest, if it ends up close to the mark, I can't see southern areas seeing much in the way of snow until later in Winter.  This being due the expectation of cold spells from mainly northerly outbreaks until February.  However, there is always potential for everyone in these situations and of course it really won't take much to beat last year!  It does sound a bit like a mid-noughties type of Winter.

[damianslaw]

Always good reading other people's thoughts.

 

Variable winters of recent past -

 

 

Winter 2012/2013 was preety variable, a cold first half to Dec, a very mild second half and first half Jan, cold second half Jan, milder start Feb, colder second half and then the very cold March.

But perhaps a better example of a real  very variable winter was 08/09 which had alternating mild and cold spells of fairly equal duration, a cold first half to Dec, very mild run up to christmas, a cold end of year - early Jan period, a more average period mid-late Jan, a cold first half to Feb and a very mild second half to Feb. The likes we hadn't experienced for a long time.

 

Another variable winter was 1993/94 especially in the north, with a cold second half to Nov, a very mild first half to Dec, colder second half to Dec in the north, an average Jan, mild start to Feb and a cold mid-second half, but overall the milder conditions lasted longer than the cold, and in the south no real cold embedded itself.

 

I wouldn't class mid noughties winters as particularly variable, 2005/2006 was very static in nature, with a brief colder phase just after christmas and end of Feb, otherwise temps were very consistently average. 2004/2005 was mild in the main, only becoming cold second half to Feb. 2003/2004 was devoid of any particularly sustained cold weather, a couple of northerlies at the end of Jan and Feb otherwise average or mild throughout.

 

Winter 00/01 was quite variable again more so in the north, a very mild first half to Dec, cold end, a mild first half Jan, colder middle, fairly cold end Jan and much of Feb thereafter.

 

I like the sound of a variable winter, provided the colder periods last longer than the mild ones, and that we don't see anything too mild. 2008/2009 was very enjoyable in this respect with the exception of the run up to christmas, the period from christmas to mid Feb was mostly cold or just average with only a short burst of mild conditions mid Jan. 

[Man With Beard]

I was thinking along the same lines as Roger until I started reading the OPI thread - now I don't know what to think. However, on reflection, I'm wondering if this finally will be the year to revisit 1991 and a proper severe cold pool from the east. My thinking is that the Scandi High, quite unexpectedly, emerged as the main player of the summer, and IIRC nearly so nearly tipped the scales on the Atlantic during January 2014 - i wonder if this is now a long term trend and if there is the absence of such a strong Canadian/Greenland vortex, perhaps any Scandi/Russian High will be able to assert itself westwards.

Edited October 23, 2014 by rjbw

[johnholmes]

Detailed version -- highly variable winter pattern expected

 

 

 

 

thanks as always Roger, I don't think anyone could really challenge those headlines. You can also be more accurate in your short term ideas than many over this side of the water. What I disagree with is the detail, I honestly feel it is impossible, no matter what system is used, to predict in any detail of even approximate dates for deep cold or very mild and changeable. Maybe a trend early, late or mid term in a 3 month cycle but I am at a loss to see how such detail can be given. I do have to admit that your system, in spite of trying hard to understand it some years ago when you went into a lot of detail to try and help those of us with an open mind, is still a bit of a blank in  most aspects. Still hats off Roger you are known for taking time and a huge amount of effort to produce your forecasts, again thank you.

[Gael_Force]

I was thinking along the same lines as Roger until I started reading the OPI thread - now I don't know what to think. However, on reflection, I'm wondering if this finally will be the year to revisit 1991 and a proper severe cold pool from the east. My thinking is that the Scandi High, quite unexpectedly, emerged as the main player of the summer, and IIRC nearly so nearly tipped the scales on the Atlantic during January 2014 - i wonder if this is now a long term trend and if there is the absence of such a strong Canadian/Greenland vortex, perhaps any Scandi/Russian High will be able to assert itself westwards.

 

This is a good example of how an uninspiring OPI figure is not the death knell on winter hopes - MMW rides to the rescue in Late January.

 

http://curriculum.pmartineau.webfactional.com/wp-content/svw_gallery/test/gif/1991_01_28.gif

 

Animation courtesy of Patrick Martineau.

 

Meteociel 15 day archive for corresponding period.

 

http://www.meteociel.fr/modeles/archives/archives.php?day=20&month=1&hour=0&year=1991&map=7&mode=2

[Methuselah]

Did any of the annual winter soothsayers predict a snowless winter, last time out? No, I thought not.

[LomondSnowstorm]

Did any of the annual winter soothsayers predict a snowless winter, last time out? No, I thought not.

To be fair to RJS he did go for a significantly above average winter temperature-wise last year, as most people did for the first half of winter at least, and specifics like snowfall totals are notoriously difficult to predict (not to mention that it wasn't a snowless winter anyway IMBY and certainly not for the poor ptarmigans up Cairngorm who got buried in metres of the stuff ). 

[BLAST FROM THE PAST]

Did any of the annual winter soothsayers predict a snowless winter, last time out? No, I thought not.

Maybe not but the extra storminess was picked up on, but to be totally snowless? Probably not

BFTP

[DAVID SNOW]

Did any of the annual winter soothsayers predict a snowless winter, last time out? No, I thought not.

 

Have a look at the archives Pete and you may well find a members forecast (winter 2013/2014)  The forecast was for a mild wet and windy winter..................

 

It was Ian Pennell I think, his forecast for last winter was very accurate.

Edited October 25, 2014 by DAVID SNOW

[snowking]

Always great to see Roger's thoughts and they never end up being too far away from the mark so thank you for the time and effort you put in to this.

 

Time is at a little bit of a premium for me unfortunately so I am not able to offer anything too in depth forecast wise, but thought I would offer up some analogue years for everyone to have a play around with.

 

So first of all let's match up some years. The OPI proves useful for this:

 

 

Just to break things down, we have listed the 9 most negative OPI years (thanks to BFTV for the figures for this). We also have the CET figures (from HadCET) for each of these years. Blue highlighting indicates that this CET figure is below the 71-00 average, and red indicates the temperature is above average. We also have the QBO and ENSO state noted.

 

The first thing to note, as has been suggested many times over in the OPI thread, is that a below -1 OPI figure generally leads to a colder than average winter. So, lets break this down even further to match the anticipated conditions for the forthcoming season:

 

 

So, that gives us three matching years. For reference, the closest ENSO match of the three is 76/77, QBO wise 76/77 and 09/10 provide the best analogues, but neither are anywhere near as strong as the anticipated value this year - which certainly provides an advantage stratospherically I would imagine.

 

The only potentially scuppering factor this year, and I know this has been mentioned by Ed too, is solar activity. Of the three years listed above all of them occurred during a time of solar minimum (Flux < 110). This year we look likely, without a significant reduction in activity, to be closer to something resembling solar maximum conditions, albeit a rather weak one. With this in mind, it is also worth taking a look at 2012/13, as this occurred during similar circumstances, however the only real difference adding 2012/13 in to the mix makes is a slight strengthening of heights across the pole.

 

So, let's take a look at what the composites give us:

 

DECEMBER

 

 

Overall it paints a rather cool and unsettled theme for the UK.

 

JANUARY

 

 

It seems as though if we are going to have one particularly cold month, at least on the basis of these analogues, January will be the month for it to happen. A solidly below average theme temperature wise and an almost perfectly placed -NAO.

 

FEBRUARY

 

 

On the basis of these analogues, a difficult month to call. It may well be a high-risk high-gain situation, with seemingly the UK straddling the boundary between airmasses as the -NAO signature backs a little further West.

 

All in all then certainly the suggestion of a below average winter as a whole temperature wise. What would be a good sign of this coming? Well we already know that a strong Siberian high, usually created off the back of a good SAI, provides support stratospherically if it backs West in to Europe, encouraging wave breaking activity. The composites for November on the basis of these analogue years certainly suggest this to be the case too:

 

 

The other striking thing of course from that image is the suggestion of a rather stormy November overall for the UK.

 

Apologies for this not being as in depth as I would have liked, but hopefully with the provision of the figures further up the post people are able to play around with some of the analogue years a little.

 

Regards,

SK

[Methuselah]

Apologies for coming across the way I did; it was rather clumsy...But, I do believe that (as we are all folks who've been watching and thinking weather for almost our entire lives) it's intuition that we mostly use when predicting? Remember how many of us 'felt' that the Big Freeze of December 2012 would never materialize, and only went along because it was universally predicted, by those who matter?

 

When I was very young, I would swear that I could smell snow...Folks said I was a sandwich short of a picnic, but I was too often right for that.   As I discovered later, however, there was a sugar refinery two miles' away to the north east...

 

On a more lighthearted note: when's James Madden's prediction going to be published?

[Roger J Smith]

Just a few brief comments on the comments:

 

-- Last winter was only looking for one cold and snowy interval and that fizzled out as a weak high that briefly gave slightly below normal temperatures. Feel that I came a lot closer than most, given that there was so much hype about a very cold winter with a lot of snow.

 

-- Specific dates or references to portions of months are simply reports of what I see in my forecast guidance. People familiar with my forecasts probably smooth those out based on what they can recall of accuracy or randomness perceptions in past cases. But philosophically, you can see that if one is prepared to say Dec to Feb will average X, then one can equally be saying 7 Dec to 7 Mar will average Y and that your estimate for 1-7 Dec is therefore a function of X-Y (not just X-Y). The math of all this is more or less unrelated to the human calendar and we tend to focus almost exclusively on months and seasons for no really valid scientific reason (the month of course is a mutation of the lunation, so to speak, but that is a period shorter than the calendar month by an average of 0.8 days, seasons are entirely a perceptual quirk of human nature, there is no particular reason why we should have identified four equally long (almost) seasons instead of three or five or some other number, and in fact in some areas of the world that is the case.

 

In statistical terms, I found that "winter" should be neither of the two main contenders (DEC-FEB or 21 Dec to 21 Mar) but something like 10 Dec to 11 Mar. If we had too few leap years we could get that to happen after a few centuries. Summer likewise should be about 11 June to 10 September.

 

But are the two intervals between those really "seasons" or are there sub-seasons? I would argue that in the U.K. climate there are probably just two seasons, growth and dormant. In the west coast climate where I live, there are three seasons, quasi-winter (a rainy season that gets snowy on rare occasions), mixed temperate then dry/warm. There is no real autumn here at all, you just lose the dry/warm signal in about a week towards mid-October and then it's back to the winter signal.

 

Solar activity is probably not much of a factor except to say that we are now getting deeper into a long-term solar downturn despite the recent weak peak, so that overall we might expect some downward pressure on the otherwise slowly rising human modified temperature signal. That is likely why we've seen global temperatures essentially flat-lined since about 2006.

 

I think that the solar effect is no greater than 0.5 C deg which means that it tends to get swamped in the 2 or 3 deg variability of month to month temperatures and only really shows itself in longer periods which somewhat counter-intuitively may be easier to predict than months or seasons.

 

Anyway, for my current winter forecast, the expectation is lots of variety, and more so than usual. That may sound interesting enough but as one form of a bust would be a long, cold winter, there are now two ways to win sort of a thing.

[BornFromTheVoid]

Interesting forecast how do you think you did ?

 

Wasn't as wet and the northerly winds didn't really show in June/July but came along a bit later.

 

Fairly good over all

 

Just spotted this, but my opinion is that overall is that the forecast was awful! No excuses!

 

I might try a more simplified approach for the coming winter.

[LomondSnowstorm]

Our old friend Ian Brown, of the (completely busted) theory of winter modernity, has posted his thoughts for the winter on another forum http://www.ukweatherwatch.co.uk/viewtopic.php?f=98&t=4564&sid=bc6d1a9e42838471b70772eb494944c8 :

 

 

Well it's been a few years since I attempted a winter forecast, and certainly they haven't always met with success but I think as far as LRFs go, we can have reasonable confidence this winter. The main points are :

- Lack of High Latitude Blocking
- Dominant Polar Vortex and largely positive NAO/AO.
- Much above average rainfall totals in the North and West
- Milder than average, with January the coldest month.

The last 12 months or so have seen the sort of return to above average temperatures that we saw for an extended long period up until 2009. The change that we saw in our winter patterns at this time can, primarily, be put down to very low solar activity. This led to less energy in the system and enabled high latitude blocking to develop during the winter periods, this had hitheto been a thing of rarity in the previous 21 winters. Solar activity is expected to be around average over the coming months.

A weak El-Nino is likely to the prevailing ENSO situation; this doesn't correlate strongly in either way for a mild or a cold winter. though perhaps a weak El-Nino and negative QBO does trend towards colder conditions. However, seasonal modelling, which is of course essentially experimental and subject to change, sees a strongly +ve NAO set-up, very much in the pattern of the modern winters that came to define the post 1987 period. The late eighties and late nineties in particular saw a succession of above average Autumns which continued through the winter periods and that is what I envisage for this winter. US forecasters, who did generally did very well with the forecasting of exceptional conditions in America last winter, forsee a similar winter to last year, although less extreme in terms of polar plunges. A negative PNA, with low pressure spawning around the North Eastern states is expected to be the broad pattern.

Last winter we saw a pattern of continuous zonality as aggressive Lows made their way across the Atlantic bringing some exceptional wind and rain to all parts, what was different to the more traditional zonal winters was that the jet was so strong, Southern areas often bore the brunt of these systems. This winter, I expect a more traditional pattern of the wettest weather in the North and West, with High pressure closer to Southern areas.

December will be dominated by an Atlantic driven pattern once a possible northerly spell with some snow for North Western areas in particular has toppled, this could occur at the very end of November. The period between Xmas and New Year is likely to be particular stormy for Ireland and Western Scotland. Rainfall and temperature will be above average for all areas, and a CET of between 6 and 6.5 is anticipated.

January is expected to begin in the same vane before the jet moves further North and allows a mid-latitude Rex block to sit over the UK for a time; this will be the driest and coldest period of the winter. Pressure will lower over Europe and there are likely to be a series of snow events for SE Europe, perhaps extending as far West as Italy. By the final third of the month, the High will have sunk into Europe with milder and wetter weather once again the order oft the day. Rainfall overall will be average with a CET return 4.5 to 5C.

The final winter month is likely to see a continuation of the pattern that ended January with quite an intense Polar Vortex to the NW and the downstream ridging over Europe that we would see from that driver. Once again, quite wet in the NW especially but not as stormy and later on we could see some exceptionally mild temperatures associated with long draw South Westerly winds. Above average rainfall for the NW, closer or perhaps slightly below average in the SE. The CET forecast for February is 6.5 to 7C.

I hope to provide an update in early December and of course, comments are welcome.

 

It's like he never left (2009 that is)   But seriously, fair play to him for putting a forecast out again, publishing an LRF takes guts and who knows, maybe he'll get it right this time (although for obvious reasons I hope not) 

[mcweather]

Our old friend Ian Brown, of the (completely busted) theory of winter modernity, has posted his thoughts for the winter on another forum http://www.ukweatherwatch.co.uk/viewtopic.php?f=98&t=4564&sid=bc6d1a9e42838471b70772eb494944c8 :

 

It's like he never left (2009 that is)   But seriously, fair play to him for putting a forecast out again, publishing an LRF takes guts and who knows, maybe he'll get it right this time (although for obvious reasons I hope not) 

 

 

 

 

Ah yes The Madden of Mild.

Does anyone else remember his Anglo saxon four letter word moment  a few winters back when after telling us there was no way a cold scenario could develop (despite it being obvious to most of the rest of us that it would) the charts then went into cold and snow territory.

 

What deep joy that brought.

Edited November 1, 2014 by mcweather

[kimb]

The Weather Outlook are also going for 'mild' although the full forecast will be out at the end of November 

 

I'm sure Ian Brown was on the radio a few years ago talking about the even larger teapot.

The large teapot ? I didn't type that ?!

[TROY]

IT WILL BE A MILD wINTER.........WITH TEMPS AROUND 13C-15c  .....Less windy....and drier...........Early Spring .......should start second week of....February......................NUFF SAID.....

[mcweather]

IT WILL BE A MILD wINTER.........WITH TEMPS AROUND 13C-15c  .....Less windy....and drier...........Early Spring .......should start second week of....February......................NUFF SAID.....

 

Crikey I didn't realise Ian Brown had a son called Troy. 

[Hocus Pocus]

IT WILL BE A MILD wINTER.........WITH TEMPS AROUND 13C-15c .....Less windy....and drier...........Early Spring .......should start second week of....February......................NUFF SAID.....

Well as constructive and informative forecasts go this one's not quite up there with the best. Edited November 1, 2014 by Hocus Pocus

[BLAST FROM THE PAST]

Well as constructive and informative forecasts go this one's not quite up there with the best.

Its either someone mimicking or is Bill Farkin from another site....accuracy levels, I'm sure that will be revealed at some stage.  There are alternative methods, then there's ALTERNATIVE methods

 

BFTP

[johnholmes]

IT WILL BE A MILD wINTER.........WITH TEMPS AROUND 13C-15c  .....Less windy....and drier...........Early Spring .......should start second week of....February......................NUFF SAID.....

 

welcome to another comic for Net Weather.