Netweather winter forecast

[NorthantsSnow]

Another ridiculously mild January?

To be honest though I'm taking it with a pinch of salt as this forecast couldn't be any more different to the one issued last month.

[Paul]

To be honest with you Dan, the only differences between this and last month are that last month the december outlook was milder, aside from that the overall winter outlook has stayed pretty much the same both in terms of temperature and rainfall for the last 3 months or so.

[andy_leics22]

Thank you for taking the time to do the Winter forecast, much appreciated

I always take long range forecasts with a pinch of salt because it is hard to predict the weather 1-2 weeks away let alone 2-3 months into the future. We will have to see what has happened by march 2008 and see if the winter forecast turned out to be pretty accurate

I would loooooooooooove a below average winter temperature wise! We deserve a great winter after all the disapointments in the past? Surely

[NorthantsSnow]

To be honest with you Dan, the only differences between this and last month are that last month the december outlook was milder, aside from that the overall winter outlook has stayed pretty much the same both in terms of temperature and rainfall for the last 3 months or so.

November was marginally below average temperature wise on the last forecast IIRC, as opposed to marginally above average this time. Perhaps not a huge difference though in the grand scheme of things and so I was exaggerating when I said "it couldn't be more different".

But for what it's worth, I still believe it will be below average

Anyway Paul it will be interesting to see how accurate this LRF turns out to be and so I shall be monitoring it closely over the coming months

Edited October 26, 2007 by Dancc

[ANYWEATHER]

Long range forecasts are always open to riddicule . Why? Because they are never correct! With the greatest respect to the forecasts on here and the forecasters, lrf is like trying to find the door to go outside when you are in a strange room/house and your in pitch darknness and your blindfolded! It takes a lot of understanding and experience to put lrf togeather ,but as always its a "shot in the dark" just like it is with other aspects of nature and trying to predict the next move etc.I think the latest forecast from NW is about as good as anyone can do with such a long range. I know a bad workman blames his tools but in this case we can blame our models/tools [as often we do] and a good forecaster can have egg on his face from bad and inacurrate info from the models even in a reliable time frame!

I think the latest winter forecast is "playing safe" and netweather are a professional team with there forecasting, as they are not like some other folks/media, who make sensational" silly" forecasts just to get ATTENTION!

Edited October 26, 2007 by ANYWEATHER

[Don]

Well done Netweather. I like the format with the added discussion

I fully agree with what others have said about not being able to go into too much detail with LRF's so I won't go into my reasons here as it will just be repeating what others have said. Detailed and sensational LRF's may make an interesting read, but at the end of the day, realistically you can only go by probabilities. I also believe it's a good idea to update LRF's regularly. I know some forecasters like to stick with their original forecast right through to the end of the season and then analyse the accuracy, but at the end of the day inevitably things will change, and this needs to be reflected in the forecast.

Edited October 26, 2007 by Don

[Paul]

November was marginally below average temperature wise on the last forecast IIRC, as opposed to marginally above average this time. Perhaps not a huge difference though in the grand scheme of things and so I was exaggerating when I said "it couldn't be more different".

But for what it's worth, I still believe it will be below average

Anyway Paul it will be interesting to see how accurate this LRF turns out to be and so I shall be monitoring it closely over the coming months

Hi Dan, wrt the IIRC, we're not just reproducing the CFS data, we use that as a base and then we process at this end, using a number of runs through the month (as it runs daily), then we average it and localise it down for the UK and so on, so it's not just a replica of the CFS output.

[reef]

Lets face it, anyone expecting a cold winter these days is going to be disappointed again and again. A cold winter is still possible in the UK, but the chance of that is minor. At the end of the day the long range models are saying it will be mild and they will probably be right. The NW forecast and Brickfielders comments look to take a good and balanced view of what current conditions are suggesting and how these might influence our winter weather without sitting on the fence.

All is not lost though if you're a cold lover, the CFS is still showing an exceptionally cold spring and early summer (I can hear Bottesford groaning already ). All to be taken with huge bucketload of salt of course, but looks quite interesting after recent years.

Hope Im allowed to post these, a March -1.5C and April -1.0C compared to average anyone?:

March:

April:

(Courtesy of NW Extra).

Mods please let me know if Im breaking any rules showing these

Edited October 26, 2007 by reef

[Paul]

No problem Reef, I was going to post the March one up later to show people anyway Will be interesting to track progress on them as at 5-6 months it's a heck of a long way out!

[Don]

Obviously those CFS charts are very much F.I. but they have consistently pointed towards a cold Spring for some time now, much like they have been consistent with the coming Winter months. They're bound to change, but it looks like a trend could be emerging.

[Snowbie]

Well done Paul and the rest of the team.

I wouldnt be much of an LRF fan but as has been mentioned here it gives an insight of what can be expected to a certain degree.

The UK MetO forecasted a couple of years back a colder winter against the mild winters we have been having and it delivered a colder winter,(but forecasted a warmer than avg summer in march2007,i will stop there)unfortunately nowadays ,winter doesnt neccessarily bring us snow chaos as it use too and prolonged cold snaps and i think by now some/maybe most people are fed up and just want to hear the word "COLD" throughout when it comes to this time of year (me too ) but myself too experienced in this field to know exactly whats needed to fall into place to put it bluntly and in laymans terms.

The winter discussion forecast is a good addition to either add to someones already misfortune or exuberance depending on what they like to read or how its read but is clearly worded on how the source of our weather is dictated from further afield.

Good Work

Edited October 26, 2007 by Snowbie

[BLAST FROM THE PAST]

For me the human assessment of the data in compiling the forecast is THE key point of interest. The accuracy is of course very important but the read and 'feel' of the effort put in for me is the essence of the LRF. That is one of the reasons why I think IB should be respected and is by me. Interesting to see how the CFS performs but this winter's LRF is pretty balnd to the past efforts. Sorry guys but it is! Also in all honesty this strong LA NINA has made things a wee bit easier...don't expect too much decent 'old' style cold

BFTP

[Don]

For me the human assessment of the data in compiling the forecast is THE key point of interest. The accuracy is of course very important but the read and 'feel' of the effort put in for me is the essence of the LRF. That is one of the reasons why I think IB should be respected and is by me. Interesting to see how the CFS performs but this winter's LRF is pretty balnd to the past efforts. Sorry guys but it is! Also in all honesty this strong LA NINA has made things a wee bit easier...don't expect too much decent 'old' style cold

BFTP

I'm not sure that I'd expect too much decent 'old' style cold even if ENSO was neutral, given our current climate!

[Paul]

I do see where you're coming from BFTP, but it's a balancing act, we wanted a clear, concise and verifiable way of producing the forecasts and have come up with a system which we think offers that and is looking pretty accurate in the relatively short time we've been using it. By using this system though, I suppose you could say we've taken away some of the personality from the forecast itself, but with things like the blogs and the new lrf discussion (which IB will be taking part in I'm sure), we are hopefully offering a reaosnable balance between the 2

[skifreak]

Fairly close to average temp Jan and Feb with increasingly above average precipitation. If the precipitation happens at the right times I could like the sound of that forecast, it certainly suggests a decent shot at something better than last winter. We managed to ski from late Nov to mid April last year on CairnGorm despite it being such a mild winter, so fingers crossed!

Blatant plug: Two new mountain webcams http://www.winterhighland.info/testcam/

[BLAST FROM THE PAST]

I do see where you're coming from BFTP, but it's a balancing act, we wanted a clear, concise and verifiable way of producing the forecasts and have come up with a system which we think offers that and is looking pretty accurate in the relatively short time we've been using it. By using this system though, I suppose you could say we've taken away some of the personality from the forecast itself, but with things like the blogs and the new lrf discussion (which IB will be taking part in I'm sure), we are hopefully offering a reaosnable balance between the 2 :lol:

Paul

Ok thanks. Any chance of a run down on what CFS has shown for this November

regards

Fred

[kold weather]

Interesting forecast there based on the CFS. It did perform very well over the summer, really nailed the zonal set-up so credit there to it.

However there is some major disagreements with regard to the strength of the La nina. The CFS if anything make sthe La nina strengthen and gets it close to record strength before slowly easing off towards summer.

BUT the ECMWF long range forecast for La Nina (which has nailed it so far!) sdhows its actually peaked and slowly weakens it over the winter and if thats the case then exactly where it ends will IMO be key for this winter because my studies have found there is a rather large weather pattern difference, with moderates tending to be far more likely to deliver cold compared to strong La nina set-ups.

From what I've seen on the CFS it has a classic strong La nina set-up on it and note December is close to average while Jan and Feb are generally 0.5-1C above average. The strong La nina average CET is about 5.2C for the winter and uually December is the closest to average though thats not always the case.

Also interesting to see a cold March, I've not really payed much attetion to what signals would suggest a cold March, tohugh I can say La Nina isn't generally one of them and Brickfielder is probably right to suspect what he does however IF the La Nina doesn't play the game the CFS wants it to then the CFS will almost certainly be over-egging the Azores high and precip+temps and we could see the pattern the CFS emerges in March happen a good deal sooner then it expects.

FWIW I do think a strong La Nina will occur and if thats the case then the CFS forecast and its interpretation will be pretty close to the mark.

By thr way one other word of warning, is the CFS based of the same atmopsheric modelling as the GFS...because if it is then its going to prone to the exact same sort of biases as the GFS model, IE over-cooking northerlies, having temps under high pressures near Europe too high, esp by night time and being way too progressive, esp at the sort of ranges we are talking about here.

Edited October 27, 2007 by kold weather

[Glacier Point]

I think we may be in danger of labelling something incorrectly here with talk of the 'Azores' ridge.

Here is the reanalysis for the oberved Pacific SSTA (seasonally lagged) pattern showing the expected baroclinic response across Pacific, N. America and the Atlantic:

• -PNA pattern evident with trough in the western States, ridge up the SE States and weak ridge in the N.Atlantic above the position expected for the Azores with slightly lower pressure around the Azores and SW approaches indicative of a weakly -NAO.
  

Here is the reanalysis for the observed Atlantic SSTA (seasonally lagged) pattern showing the expected baroclinic response across the North Atlantic:

• height rises over Greenland and weak anomalies across the sub-tropical Atlantic indicative of a -NAO and some reinforcement of the Pacific pattern trend towards high pressure further north of the Azores.
  

Here is the reanalysis for the expected forcing pattern of La Nina:

• high pressure centred just to the west of the UK and extending across the eastern Atlantic with less support for a strong sub-tropical ridge.
  

So plenty of signs for high pressure to dominate to our west, but not evidence for a strong sub-tropical ridge extending from the SW, except if the AO were very positive. If Brickfielder is predicting an Azores ridge, I would imagine he will be favouring a slightly +ve AO overall and I would be interested on is take there, particularly so given the likely declining easterly QBO.

I would call this one a mid-latitude high. If we get a -AO, a mid-latitude high is the metreological equivalent to a tinderbox, just waiting to go off in terns of northerlies, phases of Greenland and Scandinavian Highs. There will of course be phases when the AO is positive, and this will leaves us with a calm, cloudy mild feed.

Edited October 27, 2007 by Glacier Point

[Glacier Point]

FWIW I do think a strong La Nina will occur and if thats the case then the CFS forecast and its interpretation will be pretty close to the mark.

If there is a weakness to these models, they may be too weighted towards a generic Nina response. There may be a case that Nina +AO / Nina -AO may result in very different patterns.

[kold weather]

Yeah thats true, though the data I've seen at the very least would suggest if we do end up with a strong La nina during DJF then it heavily favors a +ve NAO tohugh the AO state did vary somewhat though never all that negative either.

GP would it be possible to do a chart like the ones in your post for 500mb profiles in the 6 strong DJF La ninas since 1950?

1949-50, 1973-74, 1975-76, 1988-89, 1998-99 and 1999-00.

[Glacier Point]

FWIW, shocker, but a few westerly QBOs in there and AO years taken at the height of the positive oscillation.

[Snowly does it]

Why are we assuming a strong La Nina for DJF? The current state (on one weeks data) is strong, average out its probably medium and La Nina tends to fade after October.... there seems to be an assumption to me that La Nina will be far far stronger than the likely reality?

[Glacier Point]

http://www.bom.gov.au/climate/enso/indices.shtml

Agreed, it's having a little bit of a wobble just recently and some warmer sub-surface waters showing up in region 1. Latest IRI assessment makes a case for it having already peaked.

http://iri.columbia.edu/climate/ENSO/curre.../technical.html

[BLAST FROM THE PAST]

http://www.bom.gov.au/climate/enso/indices.shtml

Agreed, it's having a little bit of a wobble just recently and some warmer sub-surface waters showing up in region 1. Latest IRI assessment makes a case for it having already peaked.

http://iri.columbia.edu/climate/ENSO/curre.../technical.html

Even looking at the Unisys chart, the La Nina does seem to have wobbled and slightly weakened, certainly not strengthened since I last looked a week ago. However, that could just be a wobble as I too think it will at least remain at its current value.

BFTP

[BLAST FROM THE PAST]

Even looking at the Unisys chart, the La Nina does seem to have wobbled and slightly weakened, certainly not strengthened since I last looked a week ago. However, that could just be a wobble as I too think it will at least remain at its current value.

BFTP

Out of interest did the La Nina this year start in May?

BFTP