Winter 2013-2014 Discussion- Part 2

[cheese 4,091]

I wouldn't mind an anticyclonic winter month if it is like February 2008, which was exceptionally sunny with lots of frost at night and even an ice day, but if we get an inversion with low cloud and static temps, then I'll be very, very angry - that's the worst weather I can think of. Nothing good can come from it.

Edited November 23, 2013 by cheese

[DAVID SNOW 5,203]

Not good 12z models today, and not too many indications of a change yet. I still think the high pressure will sit further to the west... but with cool rather than cold the best that is on the horizon for the start of December.

 

The problem we have is this:

 

 

Temps in the polar strat are now lower than the average lowpoint for the season... and they have reached this 4 weeks early. This means the vortex is strong and hard to shift. Wave activity is present, but it is relatively low level and unlikely to bend and buckle this vortex too much.

 

Any straws to clutch? Well... there is one obvious factor looking at the graph above. It really cannot go too much lower. We are on or around the record November low point at present currently held by 1997/98 when temps in November bottomed out at -78C. The lowest point ever recorded is -84C reached in Jan 99/00. In other words the current rate of decline must stop and the fact that the steep decline in temps has happened so early fills me with more optimism for the second half of winter at least. Nature has a habit of balancing things out and I expect to see a bounceback from these temps with a consequent lagged effect on the trop.

 

Solar signals are also currently not good. The sunspot number has gone through the roof at times this month, higher than at any stage since 2011, and this will not be helping blocking currently to move to high latitudes. But... again... the pattern of solar activity over the last few years reveals that after every peak there is a substantial drop off.

 

So my conclusions are not based especially on science... but rather on observation. We have managed to get a bit of blocking and made a mess of the MetO Nov temp forecast issued at the start of the month with background signals that are not good. And those background signals in terms of strat temps and solar activity may well side with us in a few weeks time.

 

It is going to be a long haul through December I think. There have been some optimistic pressure anomaly charts and december forecasts released recently - I hope they are right... but I am still seeing a slow burner of a winter with some real interest in the second half.

 

Anyone noticed how the models are moving towards the mild start to December touted by RJS? I am hoping his overall winter call is pessimistic - but even his rather mild winter forecast sees a period of proper cold in January using methods that are miles away from conventional science.

As you say polar strat temps are below average and this would mean the PV  is strong and hard to shift, but the Eastern usa is about to be hit by a massive polar outbreak possibly resulting in temperature records being broken for this time of year.

[MPG 711]

The settle spell ends at 120 on this mornings GFS. A very N/NW flow sets in throughout the rest of the run with a PV smashed all over the place. Interesting cross polar flow too.

[Weather Boy 689]

I still think we will have a Winter similar to 11-12 with just a short cold spell sometime in Jan-Feb (although I suppose now could be considered cold it's frosty outside but it's not officially Winter) I reckon we'll have a mild Christmas, looks like this coming month will be mostly dominated by high pressure near or over the country. Certainly cannot foresee a December 2010.

Few could rationally disagree with that regarding December 2010 as this was a truly exceptional month that may well not be repeated in many of our lifetimes (although it would be more likely to appear as a January or February month).I don't think it's quite right to represent 2011/2 as having a "short cold spell" at least in my location. The winter was, as you imply, generally mild, but 29 January to c. 12 February I would not describe as short. It was also fairly notable with an average temp 1-12 February at my location of -3.8C. I suppose it's short in the context of a whole winter but 2 weeks or so is more than a short snap.2011/2 gets some bad press on here (and it is easily the mildest since 2008/9 to be fair) but compared to some winters in my lifetime, notably the late eighties, it was a beaut!

[Summer Sun 52,553]

Final Winter 2013-2014 Seasonal Model Round Up from Gavin P

 

 

Still no real agreement from the models, some are going mild, some are going cold with others in between

 

The final winter forecast will be out next Sunday

Edited November 24, 2013 by Summer Sun

[Catacol 18,319]

As you say polar strat temps are below average and this would mean the PV  is strong and hard to shift, but the Eastern usa is about to be hit by a massive polar outbreak possibly resulting in temperature records being broken for this time of year.

 

The very strong aleutian ridge, which looks to be a semi-permanent feature at the moment, is encouraging troughing on its eastern side. Unfortunately we do not have a signal for a strong greenland high which might possibly do the same for us. There is plenty of winter time for this to change - but at the moment a tight vortex is ensuring that downstream wave activity from the pacific is flattening out. I hope the pattern wont flatten out so much as to produce a SW flow though some SW days look likely in Dec... but the Euro high has been rare in recent years as shown by analogue charts I posted a few days ago - so something more W to NW on average with temps average, perhaps slightly below if we can get a bit more amplification to the pattern, is my call.

 

EDIT: Quick look at the extended GFS this morning shows the recurrent atlantic ridge trying to ridge north and being flattened over and over again. Supports a NW influence on average for the 1st week at least. As ever with the weather though there is plenty of time for a change!

Edited November 24, 2013 by Catacol_Highlander

[BornFromTheVoid 12,983]

Bloody hell BFTV, your forecast is pretty much bang in line with how I see winter panning out.......like, exactly how I see it. I can't top that in terms of presentation either. It's like you read my mind!!

 

Cheers CC. What method have you been using for your own forecasts?

[cheese 4,091]

Few could rationally disagree with that regarding December 2010 as this was a truly exceptional month that may well not be repeated in many of our lifetimes (although it would be more likely to appear as a January or February month).I don't think it's quite right to represent 2011/2 as having a "short cold spell" at least in my location. The winter was, as you imply, generally mild, but 29 January to c. 12 February I would not describe as short. It was also fairly notable with an average temp 1-12 February at my location of -3.8C. I suppose it's short in the context of a whole winter but 2 weeks or so is more than a short snap.2011/2 gets some bad press on here (and it is easily the mildest since 2008/9 to be fair) but compared to some winters in my lifetime, notably the late eighties, it was a beaut!

6 inches of snow and a min temp of -13C in Feb 2012. Can't complain really.

[Buriedundersnow 2,974]

i posted this in my regional and thought I would stick it in here aswell

 

look at the last three runs day 10 850's for the ECM and u see cold coming our way bit by bit

 

 

now it is slowly bringing the cold air our way and the fact the GFS has been coming towards the ECM today then might be something to keep an eye on.

[CreweCold 27,579]

Cheers CC. What method have you been using for your own forecasts?

 

Hi BFTV. I would say that my methods are probably much less scientific than many on here, like yourself for example. I employ an approach which employs an amalgamation of a number of factors. For example I look for trends within long range modelling, I look at the state of ENSO, the QBO and have a peek at what the analogues suggest (although I tend not to take these at face value). I don't crunch numbers or anything like that, I just analyse what I see in front of me and plump for the scenario that appears the best fit. The forecast then just comes to me (it's hard to explain) and I write it down how I feel it's likely to pan out.

 

I think it's possible to be too over analytical and people can try to be too precise when formulating a long range forecast and I find a broad brushstroke (having taken a more holistic stance) usually fares best. Like I say, it's interesting how we've both arrived at the same scenario though!

[East_England_Stormchaser91 5,635]

I still think we will have a Winter similar to 11-12 with just a short cold spell sometime in Jan-Feb (although I suppose now could be considered cold it's frosty outside but it's not officially Winter) I reckon we'll have a mild Christmas, looks like this coming month will be mostly dominated by high pressure near or over the country. Certainly cannot foresee a December 2010.

Much of that winter winter was mild, we did however just miss out on one of the most brutal cold spells ever that affected Europe. That block that was in place was absolutely enormous that stretched from Alaska to Scandinavia. Also to mention that Cambridgeshire recorded a staggering low of -16c. It could've been much, much worse! I definitely do not think that we will see a winter like 11-12, the PV is nowhere near as organised as it was back then, and if we can see a block like that one of Jan/Feb 2012 form even with a raging PV dominated winter, who knows what could happen!

[AderynCoch 1,245]

That cold spell in February was practically non-existent here, characterised by not one but two failed battleground attempts which brought nothing but cold rain. There were a few cold sunny days beforehand but it certainly wasn't that cold afterwards despite seemingly everywhere else having snow for ages. A real waste and one of the most disgusting failed cold spells I can remember given its potential. The rest of the winter was pretty uninspiring too, with the only snow being a surprise fall of 1-2cm on 16th December which was gone the next morning.

 

So no repeat of 11/12 for me please.

[Captain Shortwave 21,522]

Much of that winter winter was mild, we did however just miss out on one of the most brutal cold spells ever that affected Europe. That block that was in place was absolutely enormous that stretched from Alaska to Scandinavia. Also to mention that Cambridgeshire recorded a staggering low of -16c. It could've been much, much worse! I definitely do not think that we will see a winter like 11-12, the PV is nowhere near as organised as it was back then, and if we can see a block like that one of Jan/Feb 2012 form even with a raging PV dominated winter, who knows what could happen!

I remember that morning, my housemate was driving me and a load of others from Southampton to Nottingham for a bowling tournament, whilst the M1 is a pretty bland experience, seeing everything completely covered in Ice from the extreme cold temperatures was really a beautiful sight, the best frost I've ever seen. I thought the -8C start in Southampton was cold 

[March Blizzard 1,315]

That cold spell in February was practically non-existent here, characterised by not one but two failed battleground attempts which brought nothing but cold rain. There were a few cold sunny days beforehand but it certainly wasn't that cold afterwards despite seemingly everywhere else having snow for ages. A real waste and one of the most disgusting failed cold spells I can remember given its potential. The rest of the winter was pretty uninspiring too, with the only snow being a surprise fall of 1-2cm on 16th December which was gone the next morning. So no repeat of 11/12 for me please.

Yeah, us in the NW missed out. It was pretty much an eastern/SE only event.

[Blozzel 29]

regarding the low strat temps. I think of it as keeping its powder dry for the big hit,  maybe not scientific but still.  Good news that the sunspot spike seems to have ended it might help.

[damianslaw 14,713]

Interesting to note how cold the strat currently is compared to the mean for the time of year - and no doubt a key reason why we have a very strong PV at present. As has been said, it can't get much colder, and mother nature does have a habit of balancing herself out - could we see a major strat warming I wonder as we progress through December?

[Weather Boy 689]

Interesting to note how cold the strat currently is compared to the mean for the time of year - and no doubt a key reason why we have a very strong PV at present. As has been said, it can't get much colder, and mother nature does have a habit of balancing herself out - could we see a major strat warming I wonder as we progress through December?

Also IIRC, the strat was at near record breaking low temps at this time last year and into December, then a SSW brought us a generally cold winter (all 3 months at my location below average, although December close enough to be called average). An SSW is by definition, sudden, so v. Cold temps at this point mean little, although a strat warming is I understand easier to forecast than pressure systems.I'm not saying that a cold strat now means the winter will be cold, just that a cold strat now doesn't mean it will be a mild one.

[Catacol 18,319]

Yes - there is no science to my musing yesterday on this... but logic suggests that there must be some kind of early bounce back from a strat temp profile that is 4 weeks ahead of average. Either that or we are about to have the most dismal winter in years, dominated by a strong vortex throughout and next to nothing in terms of cold. Gulp...

 

I am trying to understand the precursors to a warming event, but nowhere near it yet. Lorenzo has posted some composites over the in the strat thread that show the historical positions or troughs and ridges when previous warmings happened, but they look like averages to me and I wonder too how great the data set is. Still - its a start.

 

Where is GP when you need him. He seemed able to pick out a torque event, or a change in the MJO at distance and make a call several weeks in advance. His loss to this forum is huge.

[BornFromTheVoid 12,983]

Hi BFTV. I would say that my methods are probably much less scientific than many on here, like yourself for example. I employ an approach which employs an amalgamation of a number of factors. For example I look for trends within long range modelling, I look at the state of ENSO, the QBO and have a peek at what the analogues suggest (although I tend not to take these at face value). I don't crunch numbers or anything like that, I just analyse what I see in front of me and plump for the scenario that appears the best fit. The forecast then just comes to me (it's hard to explain) and I write it down how I feel it's likely to pan out.

 

I think it's possible to be too over analytical and people can try to be too precise when formulating a long range forecast and I find a broad brushstroke (having taken a more holistic stance) usually fares best. Like I say, it's interesting how we've both arrived at the same scenario though!

 

Such differing methods, but the same result, suppose it can only be a good thing!

[lorenzo 17,670]

Yes - there is no science to my musing yesterday on this... but logic suggests that there must be some kind of early bounce back from a strat temp profile that is 4 weeks ahead of average. Either that or we are about to have the most dismal winter in years, dominated by a strong vortex throughout and next to nothing in terms of cold. Gulp...

 

I am trying to understand the precursors to a warming event, but nowhere near it yet. Lorenzo has posted some composites over the in the strat thread that show the historical positions or troughs and ridges when previous warmings happened, but they look like averages to me and I wonder too how great the data set is. Still - its a start.

 

Where is GP when you need him. He seemed able to pick out a torque event, or a change in the MJO at distance and make a call several weeks in advance. His loss to this forum is huge.

 

Wouldn't want you wondering CH, I think we can trust the paper, It's best in class current data http://www.atm.ox.ac.uk/user/mitchell/ Very strong academic pedigree and also collaborators looking at this list of publications 

 

 

http://www.atm.ox.ac.uk/user/mitchell/dann_pubs.html

 

Dataset

 

Tropospheric precursors to warming events are something that is a backbone to studies on SSW, there are historic studies pre-dating the above paper and I am sure many to follow.

 

Yes I agree GP is a big miss, no doubt, but one thing about him not being around is that it forces the learning curve up and others can begin to work through where he left off. Safe to say that he was light years ahead of anyone else..

 

MJO forecast from CPC is updated on a Monday, so we will get an update on how they see it going later this afternoon / evening.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml#discussion

Edited November 25, 2013 by lorenzo

[Blozzel 29]

just to clarify, I was not suggesting Catacol-Highlanders post was not scientific but actually agreeing with his line of logic by using my own unscientific analogy.

[Summer Sun 52,553]

The latest met office contingency planners forecast favours a colder than average December along with January and February

 

Forecast models favour a negative NAO pattern this winter, with high pressure areas more likely to be centred over or close to the UK

Edited November 25, 2013 by Summer Sun

[Gaz1985 633]

Here's real Winter weather in the NE of America,  temperature of -8c, -18c windchill, -16c dew point  

http://www.crownofmaine.com/nmain/

[cheeky_monkey 3,987]

Here's real Winter weather in the NE of America,  temperature of -8c, -18c windchill, -16c dew point  

http://www.crownofmaine.com/nmain/

Looking at the models this morning..after this week when it warms up a bit...thereafter it looks like it will become brutally cold across much of Canada and the northern half of the USA..During the first part of December.

[Summer Sun 52,553]

Here's real Winter weather in the NE of America,  temperature of -8c, -18c windchill, -16c dew point  

http://www.crownofmaine.com/nmain/

 

Speaking of America a deadly storm is sweeping across the USA bringing heavy rain, flooding, icy roads and snow just in the run up to Thanksgiving on Thursday

 

http://www.bbc.co.uk/weather/features/25079147

Edited November 25, 2013 by Summer Sun