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AtlanticFlamethrower

Uk Sea Surface Temperatures

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Sea Surface Temperatures are important to forecasts during a cold spell as they are a heat source that can modify the incoming cold feed.

This is particularly noticable in coastal regions, as the amount of Sea Surface Mitigation can make the difference between rain, sleet, and snow.

Additionally, inland areas benefit from colder Sea Surface temperatures because with colder waters the cold feed does not have to be as cold to deliver snow.

In theory then, as the Sea Surface Temperatures fall the chance that PPN will immediately fall as snow and that there will therefore be widespread deep accumulations for any given cold feed (on the coasts as much as inland) will increase.

Retrieved 23rd

retrieved23dec09.jpg

Retrieved 25th

retrieved25dec09.jpg

As you can see from the Unisys SST anomaly map there is still some way to go before some of the waters around the UK show -ve SSTA, despite the week freeze we have just had.

Retrieved 25th

sstretrieved25dec09.jpg

+ve 0.5C - 1C in the North Sea.

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I'd be interested to see two weeks to a month from now..

In actual fact, what were the SST's same time last year or previous years?

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Not much change in two days

retrieved27dec09.jpg

Marginally colder

retrieved29dec09.jpg

I'd expect more obvious cooling to appear from next week. I expect purples (4Cs) to eventually expand from the Danish/German shore and perhaps also radiate outwards from the Wash.

It will be interesting to see how low the Channel will go - it's 10C now, down from 12C just a couple of weeks ago.

That's impressive - the waters around the UK have dropped at least 2C over the last two weeks. This means if we got the same cold spell again it would be more severe, more ppn would be snow, closer to the coasts.

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Yep December has really helped to drag those temps down...

In fact I'm willing to bet they aren't that far away from some of the late decembers of the 80s, which were generally milder then the one we;vbe just had, which sorts of levels the playing the field given we started from a much higher base.

As you say this next shot is only going to further drop those SST's, should see less modification in longer easterly drags, in the end the lower these SST's temps go the more we can maximise the colder uppers when they come along.

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Retrieved 31 December 09

retrieved31dec09.jpg

Retrieved 2 January 10

retrieved2jan10.png

Large area in the north Atlantic west of Scotland and Ireland has cooled down 1C.

4-5C temp water has emerged along the Norwegian and Danish coasts.

More of the North Sea within the grey 7.5C demarcation line with some cooler water becoming more apparent.

Channel and South West largely unchanged.

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Retrieved 4th Jan.

retrieved4jan2010.png

No real change except the central North Sea much cooler and a small purple patch appeared in the Wash area.

Actually something very noticeable - 10Cs NE of Scotland wiped out.

Still waiting for the Thames estuary area of North Sea, Northern North Sea and the Channel to significantly cool.

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Retrieved 8th January.

retrieved8jan10i.png

Important change: 7.5C line has now come down to the London estuary. This means the waters there are down -3.5C from 11C in late December. This will help lower the marginality threshold, snow will be able to fall and stick closer to the coasts from slightly less cold feeds.

Waters around The Wash now 4-5C. Channel, Northern part of North Sea slightly cooler.

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The buoys on the Met Eireann website have started showing readings well below 9C in the mornings for the first time this winter, a drop of around 1C in the last week or 2.

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Thanks for info -

How do these current temps compare to sea temps from previous winters? what is the 'average' sea surface temp for the uk in early Jan?

Paul

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Sea temperatures around the British Isles (and more specifically the North Sea) were actually colder this time last year. This is no doubt a result of the warmer summer in the east and 4th warmest November that followed. The effects of a warm summer and Autumn cant be underestimated, take a look at January 2007 for example which explains why so many snow events were so marginal that year:

2006:

post-2418-12629903501042_thumb.png

2007:

post-2418-12629903580242_thumb.png

2008:

post-2418-12629903690142_thumb.png

2009:

post-2418-12629903776442_thumb.png

2010:

post-2418-12629903884242_thumb.png

The Atlantic to our far southwest is pretty cool this year though, maybe due to the southerly jet and associated lows stirring up the waters.

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The difference on the 2007 map is striking indeed; however they must have been way above normal just before the cold of December 1995, following that summer and the very warm October. Yet by May 1996 as I recall they were well below normal, a cause of that very cold month- it seems a chicken/egg question whether the abnormal temps cause abnormal SSTs or vice versa?

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In the North Sea, which is very shallow, the sea is modified by the weather. Worldwide patterns of -ve and +ve anomalies also affect the North Sea which is another discussion :whistling:

Sea temps looking comparable with 2009 now in South but not further North.

Retrieved 9th jan 10

2wfizgz.png

This is nice cooling for just one day! Remember this is data for 8th January.

By tonight I'd imagine the London estuary will be 6C. Less stored heat for mitigating cold air.

Within the grey line is 7.5C. Darker blue within it is 6C. The first purple is 5C.

Reef, what are the exact dates for the SSTs you showed from previous years? Great variety there.

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In the North Sea, which is very shallow, the sea is modified by the weather. Worldwide patterns of -ve and +ve anomalies also affect the North Sea which is another discussion :rolleyes:

Sea temps looking comparable with 2009 now in South but not further North.

Retrieved 9th jan 10

2wfizgz.png

This is nice cooling for just one day! Remember this is data for 8th January.

By tonight I'd imagine the London estuary will be 6C. Less stored heat for mitigating cold air.

Within the grey line is 7.5C. Darker blue within it is 6C. The first purple is 5C.

Reef, what are the exact dates for the SSTs you showed from previous years? Great variety there.

They're all for the 7th January! :yahoo:

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A question for you to ponder over, what happens to the SST when all this snow and ice melts and all this cold fresh water floods into the inland water.

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A question for you to ponder over, what happens to the SST when all this snow and ice melts and all this cold fresh water floods into the inland water.

If river waters are cooler than sea waters then this will have a cooling effect on the seas near the coast.

In the second chart below it looks like the 5C line which has expanded greatly from the Wash will reach over and join up with the 5C line growing from Denmark/Northern Germany.

Surface temperatures over the next few days are expected to remain cold over the North Sea. However with a trough from the West we might expect warmer waters to be dragged up to the South West coast and the Channel. Interesting to see what happens.

Retrieved 10th Jan

nntbnp.png

Retrieved 11th Jan

j16nb7.png

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Three days' charts to update you with. The third day is the most exciting!

Retrieved 12th

2pyt1q8.png

Retrieved 13th

2v97wy1.png

Retrieved 14th

2ijqkqw.png

That is a 5C link up across the North Sea from East Anglia to North German - Denmark coast. That's a fall in temperature of -2.5C since the turn of the year, - 4.5C since Christmas.

Unisys SSTA chart shows the lower North Sea 1 - 1.5C below average, with 1C below average temperature water going up the North Sea west of Scotland.

There is also below average temperature to our west and south, but it is milder than average directly north of Scotland.

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There will be icebergs around The Wash if we get any more bitter cold Easterlys :lol:

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Has anyone got any data to show when 5C covered the North Sea to that or a greater extent?

Mind you we will still have people on the other threads posting that this winter has been nothing unusual, even when the actual data, be it from Weather magazine, courtesy of Phil Eden or UK Met show its the coldest, snowiest, since xxxx.

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I think they had a point last winter- in a longer-term context last winter wasn't particularly unusual, though it was certainly unusual for recent years.

This winter, however, will be unusual no matter how things go- be it for unusual amounts of cold and snow, or an unusually cold snowy first half followed by unusually mild snowless weather thereafter!

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Retrieved 15th January

huorgh.png

Another quite big change today - some of the pool of cold water between East England and Denmark-German coast appears to have moved north. Temperature in the northern part of the North Sea and North West of Scotland have cooled noticeably with the 7.5C line now much further north.

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Has anyone got any data to show when 5C covered the North Sea to that or a greater extent?

Mind you we will still have people on the other threads posting that this winter has been nothing unusual, even when the actual data, be it from Weather magazine, courtesy of Phil Eden or UK Met show its the coldest, snowiest, since xxxx.

If you can get hold of the charts for 1963 they should prove interesting.

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This might be interesting, but the free preview does not have the full text. Says it contains temperature data.

Apparently in 1963, and 1947 the North Sea was so cold it was killing a lot of the white fish - cod, plaice, sole etc - in the North Sea in February and March.

So much for global warming replacing native fish with new species - few more winters like this will kill off the natives!

The death of north sea fish during the winter of 1962/63, particularly with reference to the sole, Solea vulgaris

Helgoland Marine Research

Volume 10, Numbers 1-4 / October, 1964

Peter M. J. Woodhead1

(1) Fisheries Laboratory, Lowestoft, England

Summary 1. During the cold winter of 1962/63 fish mortalities were frequently reported over much of the North Sea to the south of the Dogger Bank. The sole populations certainly suffered the highest mortalities, but dead cod, plaice, whiting, dabs, turbot, brill and conger eel were also reported.

2. Fish began to die towards the end of February, and the numbers increased to a maximum in mid-March, after which they gradually decreased until reports ceased by mid-April. The development of mortalities was compared with the sea temperatures at the time.

3. The mortalities were on a large scale but not as great as previously reported for the cold winter of 1946/47; they may have been as heavy as those in 1928/29. Their distribution was more widespread than in either 1929 or 1947.

4. Analysis of fish blood serum showed abnormally high sodium levels in many fish caught in the colder waters. In some individuals the salt content appeared to approach lethal levels, but it was not known whether salt imbalance was the primary cause of death.

5. Flatfish were also attacked by a skin infection which certainly contributed to the deaths of many of these fish during the cold period.

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