Is this winter going to go pear shaped?

[North-Easterly Blast]

It has been raised by a number of people that December will be OK and give us the coldest weather of the winter this year, but then the months of January and February will be nothing but a real stinker of flat jet zonal Bartlett dross, so I am questioing whether this winter is likely to go pear shaped?

Hear are some previous examples:

2001-02: This was totally and utterly unforgettable. December 2001 was mainly anticyclonic and cold with frequent frosts but little snow for most areas and a particularly cold frosty spell began late in the month and continued into the New Year, but it all went horribly wrong and the rest of the winter and early spring were a zonal Bartlett disaster.

1996-97: Another pear shaped winter only five years earlier, and one of the most pear shaped winters on record (see below for the other) After a cold second half to November, December was cold and mostly dry, and dominated by cold, easterly weather with some snow at the end of the month and a particularly cold spell then lasted until 10th January 1997, but it all went belly up after Jan 11th and February and March were very mild and dominated by persistent flat jet zonal Bartlett conditions. This winter would have been a pretty good winter but the awful mild Bartletty February spoilt it.

1944-45: This was, with 1996-97, the other of the most pear shaped winters on record; December was mixed to begin with, but then saw a cold, frosty foggy spell later on and this led into a very cold January, with frequent snow and severe frosts, but by the end of January it all went horribly wrong, and February and March were very mild, and very similar to Feb and Mar 1997, and this winter in fact featured the largest rise in the CET from January to February in the entire 348 year long record.

You could also say that winter 1981-82 went pear shaped, as the really cold weather was over by mid January, and February wasn't much to write home about, although at least it wasn't as mild as 1997 or 2002 and did feature some colder weather after mid-month.

Some organisations including the Met Office seem to be suggesting that this winter will likely do a 2001-02. I am not so bothered about persistently cold weather during December as long as it is cold over Christmas as in December more things happen and you are busier getting ready for Christmas, whereas in January and February I find it awful not having any cold weather to look forward to, like in years such as 2002, when life is much quieter and Christmas is out of the way.

It is difficult to pin it down to La Nina bringing pear shaped winters, or even very mild ones, as winters 1996-97 and 2001-02 were not La Nina winters, they saw neutral ENSO conditions. One thing worth mentioning is that winters 1954-55 and 1955-56 were moderate La Nina winters and were cold overall especially during February. Also by the way winter 1995-96 was also a weak la Nina winter, and a weak to moderate La Nina was in place during 1984-85 and 1985-86, so it is not entirely true that La Nina conditions are bad news for our winter. A moderate to strong La Nina coincided with a very mild winter in 1988-89, and also pretty mild winters in the late 90s, but neutral ENSO winters still brought stinkers in 1989-90 and 2001-02.

I would love to hear anyones thoughts on whether this winter will be another one to join the above list of pear shaped winters (01-02, 96-97, 44-45 etc). We had two in a short space of time in the last 11 years, and when you look at the CET list pear shaped winters of the 44-45, 96-97 and 01-02 type have never been that common.

[Bobby]

I suppose the simple fact is that we don't know. Met Office seem to point to a mild winter though and considering our warming climate and decreasing amounts of cold winters then it looks even more likely. Or we could have another 1947. Let's dream.

I still think that we'll have another really cold winter, like in the 80's or even 63. Maybe even 47, have to get lucky though.

[Gavin P]

Could 81/82 also be added to the list?

As for this winter, I believe we'll have a reasomable December, with the cold possibly peaking around Christmas/New Year. What happens afterwards, I'm not sure yet.

[Snooz]

NO.. but can I have better than EVENs on that coin toss please hehe.. Winter hasn't even started yet so until it gets underway how would anyone know which way to flip the pear

Sorry, that was was way flippant.. but something is afoot, hence my 'no' bet on an essentially 50/50 call

[NorthantsSnow]

I still think that we'll have another really cold winter, like in the 80's or even 63. Maybe even 47, have to get lucky though.

I agree with you there. And it will certainly come out of the blue as well because people won't be expecting it.

Things can change rapidly in the world of weather and I think a cold, harsh winter is long overdue

[PersianPaladin]

In short: yes.

But better the way of the pear, than the orange.

[West is Best]

I think the La Nina link you mention is extremely important to downstream jet patterns and temperatures. As you rightly point out both 2001/2 and 1996/7 were neutral. This year is building to a moderate/strong La Nina. It's a very good signal, even if the correlation to cold UK winters isn't absolute. Here's a good link:

http://www.cpc.ncep.noaa.gov/products/anal...ensoyears.shtml

I remain confident of plenty of serious cold this winter for western Europe, including the UK.

[Nick F]

It has been raised by a number of people that December will be OK and give us the coldest weather of the winter this year, but then the months of January and February will be nothing but a real stinker of flat jet zonal Bartlett dross, so I am questioing whether this winter is likely to go pear shaped?

Hear are some previous examples:

2001-02: This was totally and utterly unforgettable. December 2001 was mainly anticyclonic and cold with frequent frosts but little snow for most areas and a particularly cold frosty spell began late in the month and continued into the New Year, but it all went horribly wrong and the rest of the winter and early spring were a zonal Bartlett disaster.

1996-97: Another pear shaped winter only five years earlier, and one of the most pear shaped winters on record (see below for the other) After a cold second half to November, December was cold and mostly dry, and dominated by cold, easterly weather with some snow at the end of the month and a particularly cold spell then lasted until 10th January 1997, but it all went belly up after Jan 11th and February and March were very mild and dominated by persistent flat jet zonal Bartlett conditions. This winter would have been a pretty good winter but the awful mild Bartletty February spoilt it.

Perhaps it would be worth comparing winters where a strong La Nina was present, none of those examples you have above had a strong Nina present.

The last winter to have a strong Nina present was 1999/2000 which had a December with a mixture of mild and cold spells, Jan was mild (4.9) and Feb well above average (6.3) so a bit of a crap one for cold; before that 1998/99, this was a mild winter too; 1995/96 had a moderate Nina - but that turned out pretty cold for some; then you have to go back to 1988/89 for another strong Nina winter - after a cold November it was a very mild winter to follow; then 83/84 fairly cool winter by 80s standards cold by today's standards; 1974/75 had a moderate Nina - very mild Dec and Jan, average Feb; 70/71 had a strong Nina - Dec fairly cold, Jan and Feb close to average ... and I could go on but work beckons.

I remain confident of plenty of serious cold this winter for western Europe, including the UK.

That's a pretty bold ramp there WiB, remember some on here will hold you to this!

[KTtom]

Could 81/82 also be added to the list?

Obviously depends where you live...'82 gave me the biggest snow event in 40 years early Jan. The rest of winter wasn't too bad either

Can anyone please define Nina?

[West is Best]

That's a pretty bold ramp there WiB, remember some on here will hold you to this!

Nick I haven't even begun yet!

I think we're going to see some very potent spells of penetrating cold, with widespread and heavy snowfalls pretty much throughout the UK at times.

[Nick F]

Obviously depends where you live...'82 gave me the biggest snow event in 40 years early Jan. The rest of winter wasn't too bad either

Can anyone please define Nina?

La Niña is characterized by unusually cold ocean temperatures in the eastern equatorial Pacific, as compared to El Niño, which is characterized by unusually warm ocean temperatures in the Equatorial Pacific. Click here for a whole list of frequently asked questions.

More here on its impacts: http://www.publicaffairs.noaa.gov/lanina.html

Nick I haven't even begun yet!

I think we're going to see some very potent spells of penetrating cold, with widespread and heavy snowfalls pretty much throughout the UK at times.

Good luck, many of us hope such a winter comes along - been a long-time coming, think even Philip Eden light-heartedly hinted at this being the year in one if his books I recall - will have a look for it.

[KTtom]

Thanks Nick. WIB, you can't really believe that surely.......do you?

[I remember Atlantic 252]

ive seen a half decent november snow sunday night and a few frosts, the rest of winter will be mild but bound to see occasional frost or snow maybe the odd 2 day cold spell in december february and march, January will be bartletty and zonal, january has not been good for me in the last 3 years no snow and virtually no frost

[West is Best]

Thanks Nick. WIB, you can't really believe that surely.......do you?

Yes I really do. I think we're in for a cold one. We've been in a pronounced pattern change since mid'summer' and I see no sign of that changing, especially with the La Nina.

As I mentioned elsewhere, this must be just about the most blocked autumn on record I'd have thought?

[Paul]

Can we keep it on topic please, the original poster made an effort to get the ball rolling with a factual post, so perhaps we can keep it that way?

[BLAST FROM THE PAST]

54-56 were strong La Nina. I did a comparison re the affects on winters by strong La Ninas. The result was pleasantly surprising. Going from average as starting point during the 20th century with strong La Nina there was 1 very cold and 1 very mild winter, 3 mild, 2 cold, 3 mild to average, 3 average to cool. So the result is fairly evenly split and it may well be the state of the QBO and AO that were the factors which forced it either way. I think that there is a shout for one cold month overall with close to average for the other two. For me a winter only goes the way of the pear if all 3 are mild to very mild.

BFTP

[skifreak]

As for La Nina there is some sort of correlation for the Scottish Mountains at least, the best winters coming with moderate La Nina events, a strong La Nina doesn't seem to swing things in favour of mild or cold, but what relationship there does seem to be is that strong La Nina event winters tend to be one extreme or the other, either good or very poor but rarely average.

[Nick F]

Carrying on from my above post pointing out La Nina years, it appears that strong La Nina winters strongly correlate to mild winters for the UK such as 88/89 - 98/99 - 99/00, whilst moderate Ninas at least give a chance for a more average even colder winter like 95/96 and 83/84. So, lets hope La Nina weakens to moderate this winter, signs that it may. IF it remains strong then it could well go pear-shaped.

[Gavin P]

The latest ECMWF update indicates that La Nina will never really become strong. Generally ECM is forecasting it to peak now and then gradually weaken through the winter. So most of the winter may well be moderate trending weak late in winter. Admitedly other models go for a much stronger La Nina, but it just goes to show theres not complete agreement about this.

[North-Easterly Blast]

Please keep on topic. This thread is to do with the possibility that this winter may go pear shaped, I mean do a 96-97 or 01-02, start off with a rather cold December and then be a zonal Bartlett disaster in Jan and Feb, not for discussing totally very mild winters like 88-89, 89-90, 97-98, 06-07 etc.

[Weather-history]

, not for discussing totally very mild winters like 89-90, .

1989-90 wasn't actually a totally mild winter. December 1989 wasn't that especially mild and north of the Border, it was the coldest December since 1981 with a notable cold spell mid month and it was colder than December 1962. So for Scotland, this winter could be added to the list.

For Northern Ireland, it was the coldest December since 1981 and for the CET since 1982.

[Nick F]

Sorry NEB for going o/t, but you are rather the narrowing the window for discussion - as the winter may start pear-shaped in December and get better in Jan/Feb - who knows? Other than guessing, we can only maybe predict how this winter may proceed based on past winters with similar global patterns, ie. the reference to La Nina. Anyway ... your wish is our command.

[Weather-history]

1874-75 was a beauty, 6th coldest Decembers on record for the CET (-0.2) to the 13th mildest January on record for the CET (6.4)

It recovered somewhat during February but that winter went pear-shaped around New Year in a big way

http://www.netweather.tv/forum/index.php?s...&hl=1874-75

[Matty M]

I think Gavin P mentioned what is happening before and cudos to him.

Cool/Cold November followed by a mild December/January and February.

[VillagePlank]

I think we're going to see some very potent spells of penetrating cold, with widespread and heavy snowfalls pretty much throughout the UK at times.

The 'normal' temperatures experienced over the last four or five months will surely have an effect on the SST's. They may not be anomalously cold, just yet, but the ocean has a latency, and you'd expect historic signs to prevail in some 6 months or so (why do the MetO use May SST's for winter forecasts?)

Should we see falls in SST's, however, I would assume:

(i) Lack of PFJ

(ii) Lack of moisture (no snow )

(iii) Lack of ocean/atmosphere coupling modification

So, I would say, heavy snow periods would be associated with frontal systems, almost exclusively, and convective synoptics, such as an arctic maritime feed will produce less and less as the winter progresses (as will cold zonality)

I reckon we're going to feel it this winter, but perhaps not in the traditional way.

So what do I reckon: Convective wintry showers on and off until the New Year, followed by colder synoptics 'digging in' as the SSTs take effect, where we will need frontal systems (particularly cold fronts moving over a relatively warm UK) to deliver the goodies. With this in mind when you see that Bartlett just moving in from FI, look just beyond for potential.

And that's about as good as a VP forecast gets, I'm afraid - wrapping this up in fully hopeful form - I would say that this season we will be looking for warm incursions and not the other way around - which gives rise to the notion that the winter will, or is, going pear-shaped; especially if set against a context of, say, the 1980's.