Sst's And Sea Ice - Trends

[SMU]

Our friends over at wxrisk.com certainly know their stuff. Two issues I would guard against though:-

1. Predicating the mean troughing forecast in the eastern Pacific on currently observed SSTA / AO is a little dicey, particularly as the Pacific Jet is likely to become unstable and could go the other way (although agreed at the moment this looks only likely in relation to MJO).

2. Calling La Nina is a little early - we need much more evidence than currently shown and reassuring noises from NOAA and last UKMO 3.4 region place it somewhere between 0 and -1. If it carried on for another month or two, then I think we could be justified in the La Nina pronostication. Also, I'm not sure about the movement of the cold pooling off the western coast of N.America - seems to be translating eastwards a little.

So ENSO neutral for me until I see more evidence.

Definately worth keeping an eye on though and could yet scupper many a LRF although I think fortunatley for us we have our own set of SSTAs to insulate against any mild tendencies from an invigorated polar jet- still I'd prefer a jet over Florida than Newfoundland!

GP

Morning GP

The Winter Forecast is released today- that one will be very interesting- I reakon the Parameters will be -PDO, NAO swings to Neg POS- No sustained periods either way, ENSO- La Nina-

And in terms of the States- a definate Midwest Winter/ Northern Plains- with below average Snowfall for the north-East-

Strong Alaskan PV with contined storms till start of Dec where it all begins to drop in to the Midwest-

Hurricane season Not seeming to figure on that one- NO apparent analogues- and a bit of an Accuweather Bashing!!!

regards

Steve

[Tom Montalbano]

Hi Steve & GP,

Steve, if you`re right in your assumption re. wxrisks` winter forecast & the specific elements of the forecast,

how would that impact on N.W.Europe, esp. the U.K?

For what its worth heres Accuweathers winter forecast for the U.S:

http://wwwa.accuweather.com/promotion.asp?...age=winterfrcst

Regards,

Tom.

[Cecil Hogmanay Melchett]

Looks to me like those widespread negative anoms to our north are now beginning to shrink,still above average ssts towards NW Russia.

[TG312274]

Looks to me like those widespread negative anoms to our north are now beginning to shrink,still above average ssts towards NW Russia.

Hardly mate, according to the newest maps the dark blues have spread around the bottom of Greenland which is crucial. There are also dark blue colours developing around Novaya Zemlya. Cold anomalies also developing around the 45 degree North line at 35 degree West in the mid-Atlantic.

[J10]

On this thread there is some history of SST anolomies for much of October, and IMO the cold pools around Greenland/Iceland are remaining intact.

[Methuselah]

Hardly mate, according to the newest maps the dark blues have spread around the bottom of Greenland which is crucial. There are also dark blue colours developing around Novaya Zemlya. Cold anomalies also developing around the 45 degree North line at 35 degree West in the mid-Atlantic.

That looks good for us; most of where weather comes from the west anyway???

[SteveB]

This is todays latest SST chart

And this is the chart from this time last year, quite a difference

[The Eagle]

This is todays latest SST chart

And this is the chart from this time last year, quite a difference

Hi Steve,

So in general the ssts around us are milder, I find that troubling also the warm sst south of Scandi too. Can we take much from this?

[Red Raven]

This is todays latest SST chart

And this is the chart from this time last year, quite a difference

My first post :blink:

Those SST charts are very interesting - they do show quite a difference from last year. SteveB where did you get the charts - i'd like to look at them in more detail if possible.

thanks

[Glacier Point]

Hi

Not sure what makes you think they are shrinking - if anything they have continued to intensify.

Agreed that east of the arctic circle there is much catching up to do.

However I have been sifting through the archives and followed charts from Nov 68 all the way to Mar 69 for the last half hour or so (and very enjoyable too ). Comparing where we are now to Nov 68 it is clear how the sands of time have changed the complexion on things. All the northern hemisphere was nicely cold already by this time - and the 1st arctic incursions came south by/after mid-month in November.

This was a pattern that continually re-occured for the next three months or more with surge after surge of northerlies followed by easterlies and back again. The Greenland High dominated the whole proceedings with the jet well south. (You could float ice in may of our surrounding seas that winter - so no worries about SST's then!!

Tamara

SP, I have looked at comparible years to see where we stand in respect of cold air coverage. For my selected years (1959, 78, 84 and 95 - years with neutral ENSO and weakly developing La Nina following periods of El Nino then ENSO Neutral conditions), comparisons reveal:

1. The extent of the cold air denoted by the polar front is comparible, if not as much as any of these years.

2. The extent of what I would term 'intermediate polar air' at between -20 and -30 C 850hPa is very much less in 2005, noticeably so even with the more recent 1995 comparison. As a result, Eurasia appears to be anomolously warm despite the realtive greate extent of the polar front.

3. The core cold air is located over Greenland as with all years although this year would appear to have colder than normal values associated. It is also worth noting that the -30 C 850 hPa values are as far south as they have ever been in the comparison years.

So the conclusions to draw ?

i) The polar air mass would appear to be on a par with the comparison years, if not greater so there are no issues about warming synoptics - perhaps indicative of the lower solar activity year taking effect. The only difference is that the extent of intermediate cold air which would be necessary to bring 'average' values to the continental interior is missing - a dilution effect if you like.

ii) Really cold polar air exists over Greenland, and the very low values allied to the low lattitude of this cold are also perhaps suggestive of falling incoming radiation and the synoptics of the last couple of months.

So we are not behind the game in terms of patterns but definitely so in terms of playing catch-up for the effects of the last year's warmth. The trend is very definitely positive although this does obviously flag up the relative high point from which we start.

Regards GP

[SteveB]

Sorry darkman I would have said that the SST are a lot better this year than they were last year mate, I wouldn't worry to much about the greens around the UK, it's the dark blues around greenland that are most encouraging, not there last year :blink: .

[West is Best]

My first post :blink:

Those SST charts are very interesting - they do show quite a difference from last year. SteveB where did you get the charts - i'd like to look at them in more detail if possible.

thanks

Welcome Red Raven.

I agree - those SSTs are extremely interesting. Although we're having a ridiculously warm autumn - probably heading for the warmest ever on record - I've often banged on about SSTs in winter. This year is much, much, better for cold lovers.

I'm not reading anything into this but there have also been stunning heavy falls in the Rockies - amazingly early falls. Some resorts have snow depths which they would only normally achieve by the beginning of January! This is a total contrast to last year, which was quite a struggle. There have also been early falls in the Alps in the past few days.

These are not enough imho to dampen my thoughts for a mild start to the winter, but I'm definitely not going to rule out cold possibilities.

[SteveB]

My first post :blink:

Those SST charts are very interesting - they do show quite a difference from last year. SteveB where did you get the charts - i'd like to look at them in more detail if possible.

thanks

http://www.weather.unisys.com/

click on archive images, then SST, then you must click on size to get those images.

[kold weather]

West this is also coupled with VERY cold Greenland temps compared to recnt years at the surface(-57C i think in October,a record if I remember rightly there!)

Then you have the artic ice pack which is now once again close to average after going on a rapid upsurge.These things I think are all thanks to the solar min,off course we are gonig through global warming,all that means is that colder periods will be warmer but still colder relative to the milder period.

Well,whatever does happen this winter,at least the build-up is extremely intresting!

(Darkman,the SST's around us don't really matter,those out in the atlantic are the important ones really,esp to our north.)

Maybe we won't moan about northerlies being weaklings compared to the past witht he way those anomilies are setting up at present in the north.

Edited November 6, 2005 by kold weather

[SMU]

West this is also coupled with VERY cold Greenland temps compared to recnt years at the surface(-57C i think in October,a record if I remember rightly there!)

This loop is most useful=

SST loop-

S

[The Eagle]

Sorry darkman I would have said that the SST are a lot better this year than they were last year mate, I wouldn't worry to much about the greens around the UK, it's the dark blues around greenland that are most encouraging, not there last year :blink: .

It is interesting to note in the loop the surge of cold ssts out of western Greenland

[SteveB]

Yes it is, as Steve M says lets hope it continues to push further south

[SMU]

Yes it is, as Steve M says lets hope it continues to push further south

Also one important piece of information is as of today for the first time since Mid Dec 2004 the Northern Hemisphere Sea ice cover has recovered to Normal values-

Best Regards

Steve

Also one important piece of information is as of today for the first time since Mid Dec 2004 the Northern Hemisphere Sea ice cover has recovered to Normal values-

Best Regards

Steve

PS Current live winter link-

Click listen now

Link

Larry cosgrove top american pro met

Top dog now on from NCEP- Wheres damien???

Talking about NAO... LISTEN IN.......

Edited November 6, 2005 by Steve Murr

[The Enforcer]

Time for an SST anomaly progress update over the last month or so:

http://weather.unisys.com/archive/sst/sst_anom-051002.gif

http://weather.unisys.com/archive/sst/sst_anom-051009.gif

http://weather.unisys.com/archive/sst/sst_anom-051016.gif

http://weather.unisys.com/archive/sst/sst_anom-051023.gif

http://weather.unisys.com/archive/sst/sst_anom-051030.gif

http://weather.unisys.com/archive/sst/sst_anom-051106.gif

In summary, the cold anomalies are not just holding on to the north and north west of the UK, but have now linked up with the other cold anomaly to the west of Greenland. In addition, the rate of cooling has increased across the North Atlantic, so thatthere are fewer areas of high positive SST anomalies.

It is now got to the point where it is worth looking at the SST position with respect to the start of previous Decembers:

http://weather.unisys.com/archive/sst/sst_anom-981206.gif

http://weather.unisys.com/archive/sst/sst_anom-991205.gif

http://weather.unisys.com/archive/sst/sst_anom-001203.gif

http://weather.unisys.com/archive/sst/sst_anom-011202.gif

http://weather.unisys.com/archive/sst/sst_anom-021201.gif

http://weather.unisys.com/archive/sst/sst_anom-031207.gif

http://weather.unisys.com/archive/sst/sst_anom-041205.gif

The last time there were any sort of reasonable cold anomalies at the beginning of winter (and therefore one could argue that the sea was genuinely cold) was back in Dec 2000. The cold anomalies were not as widespread as they are now, but this may well have had some impact on making that winter 00/01 the coldest of the winters which the dataset covers. Some of the other years have a certain degree of cold anomalies present, but there are also some warm anomalies alongside them in the Iceland area, which leads me to believe it is total absence of any positive areas at that lattitude that is the key factor.

If the existing pattern can at least hold in its current form, we should at least be able to see whether cold seas in those areas have any effect on the pattern of mild winters. What happens over the next three weeks is therefore crucial.

EDIT: Have just realised that the dataset includes 1998/1999 and 1999/2000 - all the files called 8 Nov 1999 in the archive are different dates and not duplications of 8 Nov 1999. :blink:

Edited November 6, 2005 by The Enforcer

[kold weather]

Thanks Steve,just talking about SST's right now,most intresting.

about Sea ice,noticed that myslef recently Steve,no doubt the solar min is helping that to occur however there is always a delay so we may see cooler SST's around that area and the artic more often in the next few years.

Enforcer,your right what happens now is KEY to see what occurs next in the winter period,so lets see what occurs with those,I should hope they will keep expanding southwards like Steve said.I'd have thought that now those SST's will stay pretty static in terms of strength for the next month,the key area I feel is in the Pacific if we can keep the negative PDO,looks good for now overall!

Edited November 6, 2005 by kold weather

[Polar Continental]

yes very interesting discussion going on right now, they are lucky so and so’s over there, all that snow they are expecting.

Thanks for that link Steve, will bookmark that.

PS very educational too.

[West is Best]

This loop is most useful=

SST loop-

S

Very interesting to see this. If SSTs are important, as I've always maintained, then despite this loopy warmth we've been having there's every chance of a potent cold switch. I don't think we should be reckoning on the 62/63 sort of talk - it doesn't help anyone to talk like that. But there's definitely some interesting signs around.

[SMU]

Thanks Steve,just talking about SST's rightr now,most intresting.

about Sea ice,noticed that myslef recently Steve,no doubt the solar min is helping that to occur however there is always a delay so we may see cooler SST's around that area and the artic more often in the next few years.

Enforcer,your right what happens now is KEY to see what occurs next,so lets see what occurs with those,I should hope they will keep expanding southwards like Steve said.I'd have thought that now those SST's will stay pretty static in terms of strength for the next month,the key area I feel is in the Pacific if we can keep the negative PDO,looks good for now overall!

Here we go on the radio link-

Top dog from NCEP!!!!!

S

[The Enforcer]

I've been busy analysing the SST situation from 1998-2005 for the first week of November. For 1999 I've had to look at a chart from the second week as there is no first week chart archived for that year.

I've created a table which shows the relative distances of the limit of the coldest actual SSTs from the UK each year. As the SST maps have no scale, I was unable to use miles or kilometres which would have been the ideal, so instead I've created an arbitary numbering system, which I won't go into, but nonetheless enables easy comparison. the 'best' years are highlighted red.

The second point I ought to mention is that I've assigned SST values to colours based on how I interpret the sliding key at the bottom, which appears to show round numbers as lying between two colours. I've assigned a round number to a colour. If I'm out by a degree or so I don't think it matters as any correction would be to the same amount for every year analysed, so the relative differences should remain the same.

Anyway here's the table:SST_table_Nov_1.doc

The conclusion is that the current SST situation is comparable to the same time of year in 1998 (Closer than 2002, which I have been previously using as a comparison until I discovered the Nov 1998 data this evening). However, 1998/1999 ended up with the highest winter CET of all of the winters featured. This may be because the cold anomalies took a real battering during November (just like 2002):

http://weather.unisys.com/archive/sst/sst_anom-981101.gif

http://weather.unisys.com/archive/sst/sst_anom-981108.gif

http://weather.unisys.com/archive/sst/sst_anom-981122.gif

http://weather.unisys.com/archive/sst/sst_anom-981129.gif

http://weather.unisys.com/archive/sst/sst_anom-981206.gif

Conversely, even though early Nov 2000 doesn't look too promising, winter 2000/2001 had the lowest CET of the data set, maybe because by December 2000, the SST situation had not altered significantly and by that stage was far preferable to 1998/1999:

http://weather.unisys.com/archive/sst/sst_anom-001105.gif

http://weather.unisys.com/archive/sst/sst_anom-001203.gif

I'm going to produce an update to this table in a week's time to see whether 2005 can clearly stand out from the other years.

[West is Best]

I've been busy analysing the SST situation from 1998-2005 for the first week of November. .. However, 1998/1999 ended up with the highest winter CET of all of the winters featured. This may be because the cold anomalies took a real battering during November (just like 2002):

Great work Enforcer - and very interesting.

The current SST situation is certainly interesting, but having just looked at the GFS runs in the key areas from the Labrador sea through the GIN corridor (including southern Greenland) I'm distinctly worried that we may see a repeat. There's a lot of mild air forecast to push into those areas, forcing back some of the cold pooling to the far north of Greenland.

This is a key month I reckon - it could decide the winter.