Gavin P

Broadly; The wettest September since 2000 and quite a cool month as well, with cyclonic winds coming from the north or north-west much more frequently than normal. Settled periods may occur in the opening few days and again towards the end of the month, though transient ridges of a couple of day duration are possible at any point. October, also unsettled and cool - Probably the wettest October since 2004, with mainly cyclonic winds coming from the north with more frequency than normal. Frost will feature more than would be typically expected. November, I'm not sure about yet.

This is the last active link I have for Roeder; http://www.climaprog.de/website1001001.htm Unfortunatey it no longer works. If/When he returns it will be with a link similar to this, so probably worth keeping it.

CFS seems to be painting an unsettled picture quite consistently for September. Of course, we know CFS is unreliable and experimental, as all long range models are, but if its got the pattern right, the most unsettled September for a long time (perhaps 2000?) awaits most of us. This is the point most people don't understand about solar activity. A lot of people think solar maxima = zonal, solar minima = blocked. It really isn't as linear as that however. Whats most important is how active these maximas and minimas are. A very weak maxima in effect is hardly any differant than a minima. By contrast a very intense maxima followed by a weak minima would probably mean the effect of the minima is very much negated. Its the stregnth of the cycles that matters most and the culmuative effect. Regarding La Nina, it very much looks to me as though we're heading into weak La Nina winter territory. Weak La Nina is historically the most favourable state to be in if your looking for a cold winter. Though obviously there are no gurantees. Its really has been a very dreary summer it must be said.

There are all sorts of theories, but my own would be a combination of the Oceans moving into a cooler phase (Pacific really, though the Atlantic will follow) and the extended, exceptionally weak solar cycle, which appears to have an especially pronounced effect on Europe in the form of blocking. However, none of this guarantees we won't move back into our more traditional weather patterns at any point. On summer, keep in mind the UK's summers have always been poor to middling. Good summers are very much the exception here, sadly. I don't know how old you are, but if you can only remember as far back as the 1990's that will have given you a skewered view on what a UK summer should be like. The 1990s and early 00's were very much the exception to the norm. The summers we've been experiancing since 2007 are much more like what a traditional UK summer should be like. On average I believe we get a good summer, once, maybe twice a decade - In the 1990s we had five or six.

John, this has the CET back to 1900; http://www.personal.dundee.ac.uk/~taharley/centralengav_temperat.htm And this is the entire CET series; http://www.metoffice.gov.uk/hadobs/hadcet/cetml1659on.dat Put both links in your favourites, because they are a great source if information.

I wouldn't think anybody would use it as the single deciding factor for a coming season. Its just one of the things to throw into the pot, ultimately.

Joe B'astardi uses the strength of the hurricane season to forecast the likely patter for the following winter.

All these years were followed by quite cold winters. There is suuposedly a connection to active hurricane seasons and cold winters - The idea is that hurricanes take warmth into the arctic which promotes cold air being displaced southwards into the mid latitudes, presumably through SSW.

Bit of a february 1956/1986 feel to those charts Paul.

I would say a warm opening week, but otherwise quite cool with high pressure continuing to sit the west feeding in north-westerly or northerly air flows. 15.3 (I would go sub 15, but for the expected warmth of week one, I may revise this in a few days)

In the last few months we've had the coldest November since 1993, the coldest December since 1890, the warmest April since records began in 1659 and the coolest June since 1991. Weird weather.

Yeah, very forgettable. As a matter affact, I think its going to be a forgettable summer, with July coming out very much "average" also.

Wasn't there quite a bit of controversy over that one? I seem to remember Trevor Harley having a sub 30'c temperature down as the hottest day for quite a few months, then suddenly the Met Office seemed to accept an unofficial temperature/station?

Thanks John, Yes, thats very much what I was getting at. The NAO/AO is a good example. Their effects on our weather in winter are very clear and well understood. Their effects in summer are not so obvious.

I think generally the weather is much harder to pin down in summer than it is in winter. The nature of the telennections and how they relate to the synoptics is far more diverse in summer than in winter, which makes summer a harder season to predict beyond 5-7 days.

Before we get to winter we've autumn to concentrate on. CFS suggests the chance of an unsettled September and a very wet October; http://www.cpc.ncep.noaa.gov/products/people/wwang/cfs_fcst/images3/glbz700Mon.gif Think we're going to make up some rainfall this autumn.

Thanks Jethro. There is quite a bit of research going on into solar activity and its regional/global effects. The consesnsus definately does seem to be that it promotes blocking in the northern hemisphere and specifically around northern Europe, by moving the jet streams slightly. I believe Lockwood is due to publish another paper on all this in the next few weeks?

Indeed. Low solar actvity actually seems to make the weather more prone to extremes. Thats not just extreme cold, but at times extreme warmth as well as droughts and floods. It also doesn't negate all the other short term influences we know can have an effect on our weather, such as ENSO, the NAO state, the PDO state, etc... So whilst we would be one of the most prone places on earth to seeing changed weather patterns from low solar activity, it clearly wouldn't always mean cold weather, nor would it mean the weather is constantly blocked with no extended periods of zonal normality.

That is almost certainly the most likely scenario. Regional effects of an extended period of quiet solar activity (such as cooling, possibly quite dramatic cooling at that, for north-west Europe) will occur, but for the Earth itself an actual ice age is probably very unlikely especially with all the C02 we've pumped into the atmosphere. Though the truth is, nobody really knows for sure.

However, it is suspected that the UK and Europe is especially prone to weakening of the solar cycle because it appears to cause the jet stream to move south. The reasons for this are not understood, but there is more than circumstantial evidence to suggest that when the sun is on its minimum part of the cycle blocking episodes become more frequent. The evidence of effects is much weaker for other parts of the world. If these scientists are correct one of the most likely outcomes would be cooling for the UK and Europe and also more prolonged periods of extreme weather caused by buckled jet streams - So for instance a record cold month, followed quite soon after by a record warm month, followed quite soon after by a record wet month, followed quite soon after by a very cold winter, etc.... would not be uncommon, rather than extended periods of temperate normality, woth only the occasional extreme month thrown in here and there. Almost similar to the weather patterns we've been seeing since 2007? :blush:

The winter of 2009/2010 was the coldest winter since 1979 (and in Scotland it was the coldest winter since 1963)

The news from the US scientists is very concerning, though I believe the Russians were warning this was going to happen 20 years ago, so it shouldn't come as that big a surprise. Nevertheless, if these scientists are right and the solar cycle is going to switch off for a few decades, we could be in for a very chilly time of it - Even assuming we don't plumb the depths of the LIA thanks to the warming AGW has given us, that could still leave us potentially facing a Victorian type climate, which would be pretty devastating to our modern way of life.

I think they mean "what we had earlier been lead to expect" by the weather - I.E. a reference to the summery April.

I don't think Paul Hudson has really said aything *that* outrageous. Piers gets far more stick when his LRF's go down the tubes.

"Can someone please clarify that it is now the norm to ammend LRFs? Anyone looking at last winter's threads would notice a winter LRF, issued 20th Nov by crewecold: http://forum.netweat...lds-winter-lrf/ As far as I can discover there was no ammendment to this LRF at any stage, it stood or fell in its entirity. Indeed, and what is particularly pertinent, is Post #8, by a certain Mr J Holmes: Posted 17 November 2010 - 08:43 well explained and a lot of work gone into it-result known 1 March! Now maybe I'm a bit slow here, but that suggests to me that there won't be any changes to that LRF and it will be judged on its merits, at the END of the forecast period, over three months later. In fact, no virtues of humilty and adaptability being lauded on this one. Obviously, I still haven't "got it", but I'm sure it won't be long until the inconsistent judgements applied to this and the summer "LRF" will be explained to me." Rob, I'll have a go at answering. My answer would be that there has always been two strands of thought regarding LRF's. 1. You put you LRF out there and leave it to be judged at the end of the season, be it good or bad. 2. You put your LRF out there, see how things develop over time and then amend it as the facts develop - More of a rolling LRF if you like. Some people don't see the point of allowing an LRF to stand if when its clearly hopelessly wrong. The Met Office always took this view. As did Ian Brown, Metcheck and Netweather. Others think that changing an LRF as you go along defeats the object of doing an LRF in the first place. TheWeatherOutlook have always taken that view. As has Joe B'astardi and as did someone called Tom Presutti who was a well known long ranger back in the day. I don't say theres a right or wrong answer to this. Ultimately its down to the preference of the forecaster. My own preference is for putting your forecast out there and letting it stand, because its easier to verify correct and incorrect forecasts that way. If your constantly doing updates it can be hard to track down what the original forecast actually was - Though that won't be a problem in the case of Netweathers summer forecast I don't think.