Autumn And Winter Lrfs

[shuggee]

17ºC - brisk SW'ly winds, sharp showers and the daffodils budding.

We're probably talking January 2007 - here we go again!

Please continue posting your thoughts here

[Dawlish]

Summer, thanks for your post from the locked thread. Interesting about the size of the polar cell, but I'm no expert on the effect that may have on the coming winter and the effect may be random.

An big El Nino event would probably lead to the warmest year ever recorded, globally, in 2007. It did in 1998, 2005 equalled it (actually exceeded it, but there was no statistical difference) and there was no El Nino. An El Nino in 2006/7 would mean that the UK would be slightly less likely to get a colder than average winter; probably only a 1 in 7 chance, rather than a 1 in 5 chance. In my opinion, of course.

Paul

[Damien]

As we wait for today's NOAA (if it updates at all), it has been pointed out on TWO that 1990/91 was also a weakly positive NAO winter:

[summer blizzard]

Dawlish, i think that the size of the Polar Cell this year backs up what Brickfielder was saying about a late spring possibly leading to an early buildup of cold, obviously there is still time for the effect to be negated.

[The PIT]

Interesting looking at the graph. They don't do badly at predicting do they okay theres one or two bad misses but not bad overall.

[The Enforcer]

17ºC - brisk SW'ly winds, sharp showers and the daffodils budding.

Or summer in Scotland?

Well done on ousting OON as FTL.

[BLAST FROM THE PAST]

Just to clarify, severe means laying snow and ice days

BFTP

[Damien]

Today's NCEP shows an exceptionally if not record breakingly hot July; a very warm or hot August and a still very warm September, albeit now just slightly less so as the warmer air starts to retreat back across the Atlantic. October is still expected to be generally below normal from the north and east, but November is now looking milder as a slightly above average Europe pushes the cold air down again into Southern Europe though we are still very Europe-dominated/negative NAO(?). December looks below average again from the north and east and from Europe but again just slightly so.

This is echoed in the longer-term generally, only with a now slightly milder looking December and January as the mild air starts to win from the west (Atlantic) and east (Scandinavia). How this has happened so soon after Tuesday's chart I do not know. February now looks to be mild from the Atlantic with cold perhaps only clipping Kent and the far South-East of the country as it moves down into a very cold Southern Europe. A very/exceptionally positive NAO end to winter based on that chart whatever else happens.

[tinybill]

rollon winter let us winter posters come back from hibernation, cold weather gales rain looking for snow in the models, glad when sunner over lol

[The Enforcer]

With a little bit of change on every output, these daily updates are bound to cover every possible winter seasonal pattern before we actually get to winter.

[SP1986]

Theres no point in speculating this far out, but im hoping it will be a mild, dry winter.

[Damien]

With a little bit of change on every output, these daily updates are bound to cover every possible winter seasonal pattern before we actually get to winter.

I've told you before that's just not true this year.

Yes, they care changing now, but for the first time in how many months, 3? And at least two cold or continental-driven months and still on the cards for most of England anyway looking at those charts.

[Damien]

Two cold continental driven months would suit me just fine

Tamara

October and November look also very cold and continental if you want those too?

Let's hope we get the February back in distant FI as well.

[Snowly does it]

Absolutely - the more the merrier, if that was to happen.

I could almost forgive February if Dec and Jan produced the goods. Bearing in mind our winter history, if we had two cold blocked months it would be pretty sensational (relatively speaking) anyway!

Tamara

A White Christamas and New Year, top ups all through January, a warm february giving a hint of Spring but then a dramatic reversal to cold throughout March.

I'll even let those warmies have a two week Bartlett in Feb if the rest comes off, lol

[The Enforcer]

I've told you before that's just not true this year.

Yes, they care changing now, but for the first time in how many months, 3? And at least two cold or continental-driven months and still on the cards for most of England anyway looking at those charts.

But they are changing. It's all well and good sticking with a certain scenario at 6, 5 and 4 months out. When it changes at month 3, those 3 consistent months mean nothing. It could even stay the same for 5 months and deviate at 1 month out. Last winter demonstrated that at times there was very little agreement between models or even ensembles beyond a range of 5 days in terms of predicting completely opposite weather patterns (easterly vs westerly).

Also, the changes look slight because they are happening on a daily basis. Comparing outputs that are months apart would probably reveal greater contrasts. Incremental change can be devastating.

Edited July 14, 2006 by The Enforcer

[BLAST FROM THE PAST]

Can I respond to some who say that winter forecasts will be pure guess work and 'very lucky' if it comes off. True for most but unfair to say all. Agreed it should be accepted as bit of fun but some do/have put loads of work in with very good reasoning behind their methods and it should be noted and looked at if it comes off and not assumed as 'a lucky guess'. I think there are some folk on here who constantly out do the likes of the TV weather forecasters...in fact this is where I come if I'm looking for LRF and more accurate forecasts. Mods by the way the new extended outlook looks good...well done.

BFTP

[The Enforcer]

LRFs serve a purpose, but until technology allows the accuracy to improve, their limitations must be acknowledged.

[Damien]

LRFs serve a purpose, but until technology allows the accuracy to improve, their limitations must be acknowledged.

As must the continual improvements in LRFs like the NOAA NCEP forecasts. Remember the NCEP summer forecast was for hot and has gradually increased the temperature for this summer while most other people were writing off the changes of a hot 2003-style season. Howver I will condede that this was again at short-range (i.e.: now and the next two months in June when the forecast first appeared).

Incidentally little change on today's NCEP. If anything September is just slightly less mild (good). November however looks to be slightly cooler once again as either a blast from the north or Europe locks us in, though it is really hard to tell anything from that weird chart, other than the Atlantic *could* be a lot weaker for some reason in this month , and that Europe is still overall expected to be slightly above average in accordance with recent runs. December also looks slightly but definitely more securely cooler as the real colder air really starts to slowly come in towards us from the north and the south again. Encouraging shorter range news from NCEP today with a colder end to the year still looking possible.

September and October are both slightly warmer in the longer range though, while November is slightly cooler and more "locked in", like October used to be. December still has slightly milder air out towards our west and north-east in the long-term though but we are still locked in a clear cold negative NAO-type pattern from Europe. The Azores still look exceptionally cold further south. January is similar with milder air still pushing in with some quite powerful-looking potential too from the Atlantic, but most of the UK still under what looks like a long below average northerly toppler(?). A repeat of January 2004? February still has the "mild air wins" scenario but with the cold very strongly winning over all of England and Cornwall from the north and east. A very negative NAO-look to that last February chart, though the cold air is also over Southern Europe and still quite powerful and prominent there.

Edited July 14, 2006 by Damien

[bigboblee]

But they are changing. It's all well and good sticking with a certain scenario at 6, 5 and 4 months out. When it changes at month 3, those 3 consistent months mean nothing. It could even stay the same for 5 months and deviate at 1 month out. Last winter demonstrated that at times there was very little agreement between models or even ensembles beyond a range of 5 days in terms of predicting completely opposite weather patterns (easterly vs westerly).

Also, the changes look slight because they are happening on a daily basis. Comparing outputs that are months apart would probably reveal greater contrasts. Incremental change can be devastating.

I am sorry to nit pick here folks and I am not a troll honest BUT come on its July the 15th and you are talking about the weather all the way to January 2007 already???

I do'nt claim to know the science of it all - yet! - but come on honestly just how reliable are the long term models?

[Damien]

Little change today. A hot summer and rather warm September still expected. October looks slightly more average (average-slightly below to be more accurate) this time. November still has us under slightly cooler continental conditions except for the far North, which is won by the retreating(?) Atlantic. December is still slightly below average under those cooler northern and eastern conditions. So far so good.

The longer range looks to quite solidly back most of this up. January is slightly colder once again as the colder northern and eastern air still holds onto the UK, but the Atlantic is winning in Ireland and Western Scotland. Still a knife-edge that chart in my honest opinion. In February we encouragingly get that block back, with much colder air still coming down onto us from Iceland and Europe. The Atlantic is winning in Ireland though. For most of us in Britain though, I honestly expected to be staring at a much milder, catastrophic chart today, but I'm just not. And believe me, Ireland could even do quite well from that set up.

Europe is one of the coldest places in the world in that last chart, especially in the South.

[kippure]

And believe me, Ireland could even do quite well from that set up.

In what way , that Ireland is a battle ground for the milder air coming up against the colder air?

Could you post the chart or provide a link

Edited July 15, 2006 by kippure

[Dawlish]

I am sorry to nit pick here folks and I am not a troll honest BUT come on its July the 15th and you are talking about the weather all the way to January 2007 already???

I do'nt claim to know the science of it all - yet! - but come on honestly just how reliable are the long term models?

You are right to nit-pick bob!

Damien; what exactly are the success-rates of these forecasts that you say are a "bit of fun", then go on to describe as "locked in" at some point, months into the future? It is a question you always skirt, no matter how many threads of this nature that you start.

Amazingly enough, the forecasts don't change a great deal from day to day, because trying to forecast the weather in any particular month, 4/5/6 months in advance really is no better than guesswork.

Paul

[kold weather]

The only problem is as Enforcer said even if it doesn't change much at all per day, think about how many days are in a 6 month period. The best comprasion i have is a winter model. They can keep forecasting a massive Greenland block but if the model hasn't spotted a developing low at say 48hrs out then the whole thing is wrong.

I must amdit though the long range models are something a long my own personal veiws...mind you when you compare my long range reasonings with someone like Steve Murr or GP and ther eis no comprasion, those two plus a few others on here are the ones who are more likely to be correct then the likes of me and other LRF.

So many different teleconnections, if you mess up on one of them then your entire forecast can go wrong. I think for now i'll stick to hurricanes...mind you if anything to try and forecast thier strength beyond 120hrs is even harder then predicting the temps for a month like December this far out, and I'm being serious as well!

(ps, look for hurricane Epsilon and see how many times the experts forecasted to die...and how long it actually lasted!!)

[Methuselah]

I answer to BFTP, I do entirely believe that detailed weather forcasting for six-/seven-months' time is (in terms of success rate) as near to guesswork as is guesswork itself...In fact, I'd imagine that the convergence of guess and 'science' occurs far sooner than that???

Only my opinion, of course, peeps.

[Rollo]

I find these projections by Damian very thought provoking but not to be taken seriously certainly at this distance. As a cold lover it is all too easy to be carried away with hopecasting (although Damian I appreciate this is a bit more than that). Obviously we are due or overdue a severe winter but how many times in recent years has that been said.