Netweather Winter Forecast 2015/16

[Dublin Novice]

Many thanks to you guys for what has to be one of the most informative and best presented forecasts I have ever seen on this site!

 

I would regard this as a sheer Masterclass in terms of data gathering and deduction - well done to all concerned, the amount of learning material that you have supplied to novices like myself is fantastic indeed.

 

Roll on the rest of our Winter!

[johnholmes]

posted in the other thread but copied into here, 

 

Wow, I have so far only scanned the main text but read the summary. What a huge amount of work has gone into this and the many factors so well illustrated and explained.

As to the forecast, it all reads coherently and looks consistent and sensible. The wash up in March will be interesting to see how not only the Net Wx forecast panned out but also the others shown in the text.

Thank you very much both of you, now to read it fully, well recommended from me anyway folks.

[sebastiaan1973]

Thanks a lot for this piece of work. I placed a link at weerwoord.be, so the Dutch & Belgium weatherlovers can enjoy your forecast as well.

[Fozfoster]

Thanks for the hard work put in guys and if your right i shall be back to praise you again in March. ;-)

[LomondSnowstorm]

Excellent stuff as always, a really well put together forecast. 

[Azores Hi]

Great effort, well constructed forecast. All hopes for cold on a SSW for Christmas then!

[karlos1983]

A fantastic read, really enjoyed it. So much effort has clearly gone into it. Looking forward to an interesting winter ahead.

 

Thank you 

[phil nw.]

Well presented Ed and Tony.

Clear and understandable to read and a learning tool wrt all the background factors that affect our weather patterns.

 

Thanks guys for a great read-good luck!

[Captain Shortwave]

A great read, lets hope it's close to the mark in terms of cold prospects during January though I personally feel that winter might bloom a little bit later.

[Hocus Pocus]

One question regarding this excellent presented forecast and that is, is this not just a forecast based on ENSO probabilities such as a cold January followed by a warm February. I know each Nino events are never two of the same but this forecast bears a striking resemblance to the 97/98 super Nino bar the severe clod expected in January. This isn't anyway a meant as a sleight on the excellent summary just a question out of curiosity?

[cheshire snow]

Thanks Guys,well presented and so much time and effort gone

Into all that LRF,it is is appreciated

C.S

[chionomaniac]

One question regarding this excellent presented forecast and that is, is this not just a forecast based on ENSO probabilities such as a cold January followed by a warm February. I know each Nino events are never two of the same but this forecast bears a striking resemblance to the 97/98 super Nino bar the severe clod expected in January. This isn't anyway a meant as a sleight on the excellent summary just a question out of curiosity?

The winter forecast is certainly not based on one winter (97/98), but obviously when looking at all the other years when the ENSO, PDO, QBO, solar conditions were similar then it would be plain barmy to disregard these analogue years. The starting position of the strat, and EC32 dayer ensembles and other GCM ensembles output reaffirm the initial forecast for December. I haven't actually looked in too much detail at the UK surface conditions (we look at upper anomaly patterns foremostly) for any of the analogue years and didn't realise that Feb 98 held the warmest Feb record. Which in itself is interesting in coming to that conclusion independently.

 

I think for the majority of those who have spent the last two months analysing the weather patterns and going into some detail behind the scenes looking at every factor, then to ignore the super strength El Nino would be foolish. It is not by accident that the strongest El Nino's all have a similar hemispheric pattern after all. ( Look at North America 11-16 day ensemble forecast for temperature anomaly as an example). 

 

 

I would also like to thanks everyone for the postive comments. It is appreciated, because it is a daunting task writing a seasonal forecast!

Edited November 26, 2015 by chionomaniac

[BlueHedgehog074]

A really brill Winter forecast by you guys. Is well balanced with great explanations and handy diagrams for various readers to understand. Those High and Low Pressure anomaly charts, in particular, are a great way to illustrate what the pressure patterns could be like in the months ahead.

Does look as though there could be a nice treat for the cold weather fans (myself included) to look forward to in January should this Winter behave the way you expect. In a way, could see a similar scenario to what happened in January 2013 where a little Scandinavian/Northern UK High managed to acquire enough power to send Lows to the South of the UK with that chilly Easterly/South-Easterly feed.

I also like the fact you've done a more detailed version of your forecast for those wanting to see more into the background drivers and other technical stuff regarding this upcoming Winter.

Bravo guys.

Edited November 26, 2015 by DiagonalRedLine

[Hocus Pocus]

The winter forecast is certainly not based on one winter (97/98), but obviously when looking at all the other years when the ENSO, PDO, QBO, solar conditions were similar then it would be plain barmy to disregard these analogue years. The starting position of the strat, and EC32 dayer ensembles and other GCM ensembles output reaffirm the initial forecast for December. I haven't actually looked in too much detail at the UK surface conditions (we look at upper anomaly patterns foremostly) for any of the analogue years and didn't realise that Feb 98 held the warmest Feb record. Which in itself is interesting in coming to that conclusion independently.

 

I think for the majority of those who have spent the last two months analysing the weather patterns and going into some detail behind the scenes looking at every factor, then to ignore the super strength El Nino would be foolish. It is not by accident that the strongest El Nino's all have a similar hemispheric pattern after all. ( Look at North America 11-16 day ensemble forecast for temperature anomaly as an example). 

 

 

I would also like to thanks everyone for the postive comments. It is appreciated, because it is a daunting task writing a seasonal forecast!

Thanks for the explanation Chion and yes it would be foolish, but do you not also think that the starting point of this super Nino and others are different beast with the cold anomaly in the North Atlantic and the set up in the North West Pacific?

[chionomaniac]

Thanks for the explanation Chion and yes it would be foolish, but do you not also think that the starting point of this super Nino and others are different beast with the cold anomaly in the North Atlantic and the set up in the North West Pacific?

Well, obviously no!

 

When you ask this question do you do it from a basis of expectancy that an Atlantic cold pool will produce a certain pattern in December for instance? 

 

Because when we looked at the previous years when Atlantic cold anomalies existed in the same region and constructed composites they were either neutral or reinforced the EN climatology. For instance here is the December analogue - compare that to EN climatology and you will find that it is a pretty exact match!

 

 

 

 

So in short, yes, combined hemispheric aspects may cumulatively end up with a different result, but using the information that we researched ( and we researched a lot) then a winter that matches EN climatology is where the forecast ended up!

[Hocus Pocus]

Well, obviously no!

 

When you ask this question do you do it from a basis of expectancy that an Atlantic cold pool will produce a certain pattern in December for instance? 

 

Because when we looked at the previous years when Atlantic cold anomalies existed in the same region and constructed composites they were either neutral or reinforced the EN climatology. For instance here is the December analogue - compare that to EN climatology and you will find that it is a pretty exact match!

 

 

 

Cold Atlantic Dec H500.png

 

So in short, yes, combined hemispheric aspects may cumulatively end up with a different result, but using the information that we researched ( and we researched a lot) then a winter that matches EN climatology is where the forecast ended up!

It wasn't just the Atlantic I was looking at, the NW Pacific is also a lot different to back then and I would've thought this would have a big effect on events downstream?

[lorenzo]

I also want to extend my thanks also for all the comments so far, it's nice to read that people appreciate the work put in.

 

Have to say that it represented a real challenge this year, as having read so many times - El Nino winter -  it's set in stone, or has certainties etc.

 

Seems this year which is already breaking ENSO region records underpins why you see many references to 'Flavours of El Nino'. They simply are not that alike, especially more so when you add different variables in layers to the base state that already exists. 

 

Further to that, there are many posters / readers on here whose knowledge eclipses ours,it would be disrespectful or dismissive not to try and find a way through the one ENSO fits all approach.

 

Regarding last year's forecast, I fully appreciate the criticism there. The truth is it is a 'forecast' it is not a 'certainty'.

 

The positive from this is that we learned from it,  it taught new things around how EP Flux operates in certain solar conditions, how this then interacts with the Polar Vortex, how this eschewed composites. It helped refine the mechanism used to build composites beyond the standard monthly re-analysis into a more precise daily re-analysis using datasets containing anywhere between 500 and 1000 individual days of data uploaded to ESRL.

 

On a less technical side it made me question more every single composite created. May share some of the material looked at 'on the way' to getting to last night and the forecast being published if that is of further interest.

 

Again, thank you for taking the time to read through and for all the comments.

[Hocus Pocus]

I hope you  both don't take my comments in anyway as criticism, far from it I'm curious in your methodologies and what you both look  in compiling your forecasts. 

[lorenzo]

I hope you  both don't take my comments in anyway as criticism, far from it I'm curious in your methodologies and what you both look  in compiling your forecasts. 

 

No not at all HP, as I said above all comments welcome. ref: methodology - this is mainly outlined in the technical section.

[chionomaniac]

I hope you  both don't take my comments in anyway as criticism, far from it I'm curious in your methodologies and what you both look  in compiling your forecasts. 

We are not above criticism and in fact it is good to question our methodologies and approach. How are we ever going to improve without this? I know that you meant the NW Pacific as well, but we also looked at that and hence the section on the Pacific. Long range forecasting is an inexact science, but without pushing the boundaries as predecessors have also done, then we will never extend those boundaries further.

 

This El Nino is an unique beast, but there are still general El Nino atmospheric responses which are to be expected no matter what brand of EN we are seeing and these are more likely when the strength is similar to this year.

 

PS I don't think that anyone will have an Excel spreadsheet quite as extensive as the one that Tony has constructed for every factor for every winter. ( Well OK, he hasn't got lunar phases included!)

[Hocus Pocus]

Thanks for the replies guys.

[The Enforcer]

This is a good piece of work, which I found very informative. You ought to send it to the Daily Express. I would like to know what the "W" and the "C" stand for in front of ENSO on one of the diagrams?

[chionomaniac]

This is a good piece of work, which I found very informative. You ought to send it to the Daily Express. I would like to know what the "W" and the "C" stand for in front of ENSO on one of the diagrams?

Thanks TE. Warm and cold are what the w and c stand for. It's another way of saying El NIno and La Nina. You will quite often see wENSO on twitter describing warm ENSO events that have occurred.

[The Enforcer]

Thanks TE. Warm and cold are what the w and c stand for. It's another way of saying El NIno and La Nina. You will quite often see wENSO on twitter describing warm ENSO events that have occurred.

Thanks, I had thought West and Central, but clearly your answer makes more sense. I thought it was interesting that more snow cover = more likely SSW, but more sea ice = less likely SSW.

Edited November 27, 2015 by The Enforcer

[Mark Neal.]

Well Done chaps! Well thought out and presented forecast. Best of luck!