Met Office winter NAO forecast...

[kippure]

Amazing contrasts there. In 95 there was a huge plume of warm water further south in the atlantic as for this year it just looks like a weak current.The med looks alot colder in 95 now it looks like its boiling. It almost seems that theres no real heat in the atlantic at the moment?

[AtlanticFlamethrower]

I can't believe the most interesting anomalies between the two charts have been missed.

2007 - All waters around UK +1-2C

1995 - Waters around UK -1C in the North (huge cold pool around shetland!), about 0C in East and West. Only the south east touches positive.

Edited June 15, 2007 by AtlanticFlamethrower

[kippure]

I can't believe the most interesting anomalies between the two charts have been missed.

2007 - All waters around UK +1-2C

1995 - Waters around UK -1C in the North (huge cold pool around shetland!), about 0C in East and West. Only the south east touches positive.

It does look like a more general cooler atlantic.

[Gavin P]

The shallow waters around the UK are so warm on the May 2007 chart, because the weather has been so warm. As soon as temperatures drop consistently, they will drop.

The interesting things is that both charts have got a tripole look to them. Both charts have cold waters down the eastern seaboard, with warmer waters to both the north (around Greenland) and the South-West. The differances are that in 1995 the Azores region was warmer and in 2007 the area south of Greenland is warmer than it was in 1995. Nevertheless, I think the May 2007 chart definatly has the look of a -NAO pattern about it.

Edited June 15, 2007 by Gavin P

[AtlanticFlamethrower]

You still don't get what I'm saying.

The water all around UK warms us like a central-heated house is warmed by radiators on the side of the walls.

The +2C difference between 1995 and 2007 in the waters around UK implies a temperature rise irrespective of temperature anomalies in the Atlantic that may cause larger atmospheric pattern changes.

The most simple observations don't explain everything but they should not be ignored either.

[beng]

Thought I'd bring this back as the negative NAO signal is strengthening.

http://weather.unisys.com/surface/sst_anom.html

http://www.emc.ncep.noaa.gov/research/cmb/...es/wkanomv2.png

We have a very good tripole signal now - the N Sea positive anomaly (although still very high) has already moderated somewhat - and should continue to do so through July (this should allow CET values to trend closer to normal through the remainder of the summer IMO). As Gavin has stated - with sustained cold conditions these sea temps can change rapidly - although they will produce a warming effect (relative to the synoptics) whilst they remain so positive.

[Gavin P]

Yep, looking very encouraging so far. I'm looking forward to the Met's winter NAO forecast, released in just a couple of weeks, hopefully.

[summer blizzard]

Yes, we do have the tripole, though i am not sure what effect the cold anomoly over the Azores will have on the NAO outlook, though i think that this again gives a slight bias towards a negative NAO.

Also, look at the lack of warm anomolies to the north of us, this is annother good sign and perhaps expains the potency of this late June northerly.

[Stu_London]

Yes, we do have the tripole, though i am not sure what effect the cold anomoly over the Azores will have on the NAO outlook, though i think that this again gives a slight bias towards a negative NAO.

Also, look at the lack of warm anomolies to the north of us, this is annother good sign and perhaps expains the potency of this late June northerly.

Have to say I didn't think it was all that special - then again it's true to say it ended up being modified and not from the pole direct as was progged 2 - 3 days before the event

[summer blizzard]

Obviously in high summer its unlikely to feel cold unless you are under a lot of rain, however this northerly is quite potent for late June.

[BLAST FROM THE PAST]

I can see nothing but a -ve NAO call. But as we know this does not mean you know what for the UK

BFTP

[beng]

http://www.easternuswx.com/bb/index.php?sh...40&start=40

An update from our Eastern US friends - over there our guru believes his NAO predictive method may now forecast winter 07/08 in the top 3 negative NAO winters. Currently the top 3 he lists are:

1. 63-64 -1.38

2. 62-63 -1.21

3. 76-77 -0.99

07/08 stands at -0.95 (based on the May/April figures) however during June his index is down at -1.532 - so an average of the 3 months would come in around -1.14 which would put 07/08 between 62/63 and 76/77 in respect of his NAO forecast scale.

They also talk about La Nina - the general consensus being that it won't have much affect on the Atlantic NAO signal provided it gets no stronger than weak moderate.

[NorthYorksWeather]

so does that mean we are going to have a winter similar to 62/63?

[mezzacyclone]

I find this most interesting Beng, I'll gladly settle for a low Hurricane season to give us better chance of a long awaited traditional winter,

although the NHC forecast is high between 7-10 , 3 - 5 of which Major, NHC latest preds so we'll see how this effects the NAO I suppose come autumn.

Theirs similar related talk to stir the excitement of the SACRA crew every year though

[Anti-Mild]

I find this most interesting Beng, I'll gladly settle for a low Hurricane season to give us better chance of a long awaited traditional winter,

although the NHC forecast is high between 7-10 , 3 - 5 of which Major, NHC latest preds so we'll see how this effects the NAO I suppose come autumn.

Theirs similar related talk to stir the excitement of the SACRA crew every year though

This happened last year. There were all sorts of favourable signs and portents pointing towards a cold and snowy winter and I don't need to remind anybody how it went.

It is my duty as Sacra founder to advise caution. Sure some Americans are hinting of a strongly -ve NAO forecast for the coming winter, sure the MetOffice forecast based on SST's in May might be a good one but even if all the signs were good there are still no guarantees. Surely last winter taught some people a valuable lesson - it certainly taught me one!

[beng]

so does that mean we are going to have a winter similar to 62/63?

Erm did anyone say that? Answer No.

All it means is that the likelihood of the coming winter having a significantly negative NAO looks decent. The NAO forecast is one of the main predictive tools the MO use when producing their winter forecasts.

We should also note that the MO NAO forecast may not be the same as this gentleman on Eastern US - although his NAO forecasts appear to have a good track record.

It is my duty as Sacra founder to advise caution. Sure some Americans are hinting of a strongly -ve NAO forecast for the coming winter, sure the MetOffice forecast based on SST's in May might be a good one but even if all the signs were good there are still no guarantees. Surely last winter taught some people a valuable lesson - it certainly taught me one!

I'm not sure anyone in this thread has said we're going to have a cold winter? The thread is about what the MO NAO forecast is likely to be.

When/if several of us issue severe January CET forecasts at the end of Dec this year (based on stratospheric warming, AO signals, seaweed and Mystic Meg) then please do advise caution :lol:

[mezzacyclone]

This happened last year. There were all sorts of favourable signs and portents pointing towards a cold and snowy winter and I don't need to remind anybody how it went.

It is my duty as Sacra founder to advise caution. Sure some Americans are hinting of a strongly -ve NAO forecast for the coming winter, sure the MetOffice forecast based on SST's in May might be a good one but even if all the signs were good there are still no guarantees. Surely last winter taught some people a valuable lesson - it certainly taught me one!

Remember it well AM, (the kids looked at me like hungry puppys after i false-raised their hopes so high) I also took Joe Bast.ardi's (always like writing his name these winters -EDIT: note the politically correct avoidence name change by inserting a little "." ) info to heart like a mug!

Back to basics, and I gather it will be the usual "overcold hysteria"-type forecast? thanks to how summers panning out so far anybods?

[Glacier Point]

UKMET predictor pattern for may SSTA reanalysis....

http://www.metoffice.gov.uk/research/seaso.../nao/index.html

May 2005 SSTA which lead to the -ve NAO prediction:

May 2007 SSTA:

You decide, but IMO, a very definate -ve call must be forthcoming.

GP

[reef]

People need to remember aswell that a -ve NAO doesnt necessarily mean cold and snowy. Such a pattern can see low pressure anchored to the south-west of the UK drawing up mild southerlies with the Greenland high having pretty much no effect on our weather at all. Likewise a positive NAO scenario can give very cold weather (i.e December 2006 just before christmas).

Every year there are positive signs we could be heading towards a colder winter. No matter what 'signs' show themselves, we'll only know for sure once we hit December. If the jet is roaring across the Atlantic then, then its pretty likely we'll know where the winter is going.

[Anti-Mild]

I'm not sure anyone in this thread has said we're going to have a cold winter? The thread is about what the MO NAO forecast is likely to be.

Agreed. Everyone is being very circumspect about making bold statements. However, reading between the lines and a lot of people are subtly suggesting that things may be favourable, and are doing so in a manner that doesn't tempt fate...very sneaky! :lol:

I think it'll be a long time before anyone is bold enough to make a serious forecast of a cold winter for fear of looking like a fool and being shot to pieces.

[BLAST FROM THE PAST]

I agree with many and GP...-ve looks the call. We must remember the 66% hit rate the meto put on it too, -ve NAO does not mean cold UK winter but puts us in with a shout. On a personal note I think a Euro freeze is likely latter half with a UK miss again.

BFTP

[Stratos Ferric]

...

I think it'll be a long time before anyone is bold enough to make a serious forecast of a cold winter for fear of looking like a fool and being shot to pieces.

I'd give it, er, about five months. You'll see.

[beng]

Agreed. Everyone is being very circumspect about making bold statements. However, reading between the lines and a lot of people are subtly suggesting that things may be favourable, and are doing so in a manner that doesn't tempt fate...very sneaky!

LOL - not sure what you mean :lol:

[BrickFielder]

UKMET predictor pattern for may SSTA reanalysis....

http://www.metoffice.gov.uk/research/seaso.../nao/index.html

May 2005 SSTA which lead to the -ve NAO prediction:

May 2007 SSTA:

You decide, but IMO, a very definate -ve call must be forthcoming.

GP

Subtle differences on those two plots especially off the coast of Spain. Enough may be to push high pressure towards greenland more and drag any azores low towards the UK. In other words the storm track is angled towards us and will make for a cool europe but not necesaarily a cold UK.

Winter patterns though tend to be dictated in recent times by the stratospheric vortex. An easterly QBO will allow breakdowns or slow downs of the stratospheric vortex leading to blocked patterns, however this will only happen if the vortex is weak.

I have my suspicions that the vortex will be a strong one in the coming winter. I base this on the fact that the spring pattern broke down very late this year keeping the artic quite cool till late on. Despite rapid loss of ice and a significant warm up in parts of the artic I expect an early cool down to our north and towards greenland. This points to a strong vortex based around greenland which although usually giving us mild atlantic weather could give us some significant snow late winter.

Here are some charts which show some of the anomalous conditions to the north.

Note that out going long wave radiation has been on a high for about 8 months giving a steady cool down to the northern hemisphere.

Of course you can argue that the lack of ice and warm up in the artic point to a weak vortex.

[Yorkshire Snow]

People need to remember aswell that a -ve NAO doesnt necessarily mean cold and snowy. Such a pattern can see low pressure anchored to the south-west of the UK drawing up mild southerlies with the Greenland high having pretty much no effect on our weather at all. Likewise a positive NAO scenario can give very cold weather (i.e December 2006 just before christmas).

Every year there are positive signs we could be heading towards a colder winter. No matter what 'signs' show themselves, we'll only know for sure once we hit December. If the jet is roaring across the Atlantic then, then its pretty likely we'll know where the winter is going.

Hi Reef,

I take note about what your saying, ....... but give me a negative NAO rather than a positive one. This at least puts the right ingrediants in place for a decent shout of a 'cold-spell' ........ otherwise your really looking / hoping for / at cold zonality (how often does that occur these days ... or the odd toppler type of snap) ...... also ...December 2006 was mild !!!

Cheers

YS