Sea Surface Temperature And Sea Ice Trends

[kippure]

Is that a good thing? Would that provide enough energy to kick start the atlantic again ,plenty of L.P,s crashing into us?

[reef]

Is that a good thing? Would that provide enough energy to kick start the atlantic again ,plenty of L.P,s crashing into us?

I imagine it could become a problem in Autumn as cold air moving over abnormally warm seas leads to explosive cyclogenesis (low pressure formation).

It seems interesting to me though how the SST anomoly patterns have changed since 2004 during the summer. Pre-2004 it was often the case that there was a massive cold anomoly in the middle of the Atlantic with the seas to our north being consistently above average. However, now we have a warm mid-Atlantic and rather cool seas to our north:

http://weather.unisys.com/archive/sst/sst_anom-040704.gif

http://weather.unisys.com/archive/sst/sst_anom-030706.gif

http://weather.unisys.com/archive/sst/sst_anom-020707.gif

Compared to 2005:

http://weather.unisys.com/archive/sst/sst_anom-050605.gif

and 2006:

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

[summer blizzard]

While the warm anomoly may indicate a stormy Autum, it is also serving to amplify the Jet Stream currently, so that there is a mean trough just to the west of the British Isles.

[BLAST FROM THE PAST]

While the warm anomoly may indicate a stormy Autum, it is also serving to amplify the Jet Stream currently, so that there is a mean trough just to the west of the British Isles.

SB

Have meto released their 'experimental' forecast based on May SSTs yet like last year?

BFTP

[summer blizzard]

Not as far as i know however they may release it this week if it is being released in July.

[summer blizzard]

The cold anomoly in the North Sea is now a warm anomoly and the two cold anomolies are seperated, this indicates a split Jet Stream with a more powerful northern Jet Stream, expect a very hot spell between the 20th and 25th of July.

[Glacier Point]

The warm anomaly off Newfoundland is indeed a likely key player for mid to late summer, as is the couplet that ot forms with the cold anomaly around the Azores.

If we look at the SSTA from last month and marry this up with current 850 hPa values, then we see very good agreement:

http://weather.unisys.com/archive/sst/sst_anom-060528.gif

http://www.cdc.noaa.gov/map/images/sst/sst.anom.month.gif

http://wetterzentrale.de/pics/Rhavn242.html

... an excellent match on the cold anomalies off the western USA sustaining a sharp ridge, a downstream trough over the eastern USA, and a jet stream pulled up to Newfoundland which troughs over the Azores placing the UK and western Europe in a very stagnant warm ridge.

Undoubtedly the +ve AO spike during June has helped exacerbate this set-up driving low pressure and the jet further north, but the SSTA would appear to be having a significant impact on the seasonal pattern.

The current SSTA, if anything, are likely to lead to more amplified flow pattern drawing air up from further south towards the UK as that cold anomaly around the Azores strengthens and the warm anomaly off Newfoundland continues to remain very strong with all that warm airflow associated with the Bermuda High:

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

Another point to note is the strength of the easterly air flow (cooler air mid sub-tropical Atlantic) seemingly to arch back on itself from the UK towards Florida. This is the effect of the trough and it will help to reduce wind shear for tropical storm development. What this means is that greater storm activity (although there are other factors at play) will translate to a likelihood of big Atlantic depressions stalling in the Atlantic and fragmenting with some fragments getting sucked into the trough off Iberia.

This is a key player in helping to set up a repeat of the current heatwave, so beware the heat for August based on the SSTA alone.

Of course there is the AO to consider and statistically July, and August even more so, are the summer months most likely to see -ve AO which would bring less settled conditions to the UK. However, with the current heat now well ensconsed, even neutral or even slightly -ve AO values would see planty of warmth.

GP

[Bottesford]

Good read the GP and good news for a continuation of the hot summer!

Be nice to save those Atlantic gales for late Sept/early Oct when a series of strong storms should coem our way to dampen things down for the new season.

[summer blizzard]

The developmet of the positive PNA pattern has already begun and the sea surface temperature anomolies in the north eastern Pacific carry on this trend, during the last ten days, the Newfoundland warm anomoly has lost around 1.5C in terms of temperature and i expect this trend to continue.

[Dawlish]

Good read the GP and good news for a continuation of the hot summer!

Be nice to save those Atlantic gales for late Sept/early Oct when a series of strong storms should coem our way to dampen things down for the new season.

Ooooo, except that I think there will be quite a significant breakdown in our weather, introdicing significantly cooler and windier, conditions, during the last week in July. The heat may rebuild in August and I rather hope it does, as I still have decent odds on 100F over the whole summer, but this breakdown could last longer than the week I have pencilled in!

Paul

[summer blizzard]

Firstly, i will start by saying that sea surface temperature charts indicate that the first ten days of August will have the greatest potential for extreme heat because the cold anomolies to the north are too close for comfort and i would anticipate a breakdown from the west or north west for the current heat before the weather turns a lot more unsettled, especially for the west.

Secondly, i thought this would be a good time to compare the current setup to 2005. As you can see, the current setup favours a stronger ridge over Europe than 2005 due to warm anomolies in the Mediterranain Sea and a more pronounced trough in the Atlantic as well as weaker blocking, i.e. more amplified Jet Stream than last year.

Looking ahead to late Autum and winter, i would say that across the Atlantic, the current setup favours a more negative NAO than 2005 due to more cold anomolies at high lattitude and cold anomolies off the eastern USA and sub-Tropics, however this signal is being overridden by high pressure over Europe forcing the Jet Stream north, i.e. focing an Icelandic Low. Should the warm anomolies in the Mediterranian become cold anomolies, then the current setup would favour a strongly negative NAO and easterly winds.

[Mr Sleet]

The cold anomoly in the North Sea is now a warm anomoly and the two cold anomolies are seperated, this indicates a split Jet Stream with a more powerful northern Jet Stream, expect a very hot spell between the 20th and 25th of July.

Pretty good call there three weeks in advance

[summer blizzard]

Thanks, once the warm anomolies were sorrounding us with the cold anomoly to the south west i could see that therwe was potential for a very hot spell, i also think that there will be another hot spell during th first ten days of August.

[Guest Mike W]

Very interesting information by SB, but I find it confusuing that your predicting very hot weather/heatwaves [correctly though] and yet you are saying we should be seeing a climatic cool-cooling effect around this year and certainly around the end of this year and into next year, do you still maintain this, and would we not then be seeing cooler summers in years to come more so than any other season, as sulphates in the old days affected summers more than any other[when we did that sort of thing] would a big solar minimum do the same, or was this more to do with the increased volcanic eruptions that took place in the Maunder and Dalton. One last question is, do you think that solar minimum's increase the risk of volcanic eruptions occuring more often than in maximums, as It looks like that but it might not be, confirmation would be useful.

[summer blizzard]

Very interesting information by SB, but I find it confusuing that your predicting very hot weather/heatwaves [correctly though] and yet you are saying we should be seeing a climatic cool-cooling effect around this year and certainly around the end of this year and into next year, do you still maintain this, and would we not then be seeing cooler summers in years to come more so than any other season, as sulphates in the old days affected summers more than any other[when we did that sort of thing] would a big solar minimum do the same, or was this more to do with the increased volcanic eruptions that took place in the Maunder and Dalton. One last question is, do you think that solar minimum's increase the risk of volcanic eruptions occuring more often than in maximums, as It looks like that but it might not be, confirmation would be useful.

I believe the effects of the Gleissburg Minima will not be felt untill after 2011, the coming maxima in 2011 will be a full srength solar maxima. I suppose that their could be a link between volcanic eruptions and solar minima if volcanic eruptions are linked to magnetic field strengths.

Mike, i think this should be discussed in the environmental thread.

To put this post onto a relavant topic, the thing that i will be watching the most over the next few months is the Mediterranian Sea, if the sea surface temperatures are to be conducive for a European Trough, we need them to be negative howver in order for synoptics to be faviourable for cooling in the Meditteranian, we need a positive PNA setup to be dominant.

[summer blizzard]

The major change in the last week has been the loss of the cold anomolies to the west of the British Isles which should mean less southerly plumes however the signs are that anticyclonic weather will still prevail, maeaning that a warm August is likely.

I have annotated a chart to show the likely Jet Stream path...

[parmenides3]

The major change in the last week has been the loss of the cold anomolies to the west of the British Isles which should mean less southerly plumes however the signs are that anticyclonic weather will still prevail, maeaning that a warm August is likely.

I have annotated a chart to show the likely Jet Stream path...

Please could you answer two (hopefully relevant) questions.

1. Looking ahead at the jetstream charts in the =120-+240 area, the model differs from the line you have drawn enough to suggest that you disagree with the model, at least as far as the first part of August goes. Is this the case? If so, could you clarify your reasoning for a newbie like me, as I don't understand the dynamics of the jetstream very well?

2. The noaa anomaly charts are substantially different to the Unisys ones we use on NW. Genuinely, can anyone tell me why this is? Are they working on different datasets? If so, which of the two should I use as a basis for analysis/discussion?

[Dawlish]

Ooooo, except that I think there will be quite a significant breakdown in our weather, introdicing significantly cooler and windier, conditions, during the last week in July. The heat may rebuild in August and I rather hope it does, as I still have decent odds on 100F over the whole summer, but this breakdown could last longer than the week I have pencilled in!

Paul

That was the 15th July spot that I declared wrong - it was only about 5 days wrong though and the movement of that spot to Aug 1-5, looks bang on.

In hindsight, the SSTs analyses you provided, seemed contradictory, SB and GP. No extreme heat in August, SB, though it did continue through July, GP, and there was your non-commital warning about not relying on SSTs alone for heat in August. Such a lot of store is set by these SST analyses, the Met Office gives it some credence with basing their NAO sign forecast on them, but, in my opinion, the relationships between atmosphere and oceans are just too complex for us to understand enough to use them for long-term forecasting, yet.

Edited July 28, 2006 by Dawlish

[BLAST FROM THE PAST]

That was the 15th July spot that I declared wrong - it was only about 5 days wrong though and the movement of that spot to Aug 1-5, looks bang on.

In hindsight, the SSTs analyses you provided, seemed contradictory, SB and GP. No extreme heat in August, SB, though it did continue through July, GP, and there was your non-commital warning about not relying on SSTs alone for heat in August. Such a lot of store is set by these SST analyses, the Met Office gives it some credence with basing their NAO sign forecast on them, but, in my opinion, the relationships between atmosphere and oceans are just too complex for us to understand enough to use them for long-term forecasting, yet.

Paul

Agred, I suppose it really shows that no one driving force can be relied on for accuracy and has been said many times in the winter thread we must look at the 'bigger' picture. As far as I'm concerned that means looking beyond the planet too. Having said that I think GP and SB provide a very good service

BFTP

[Dawlish]

Paul

Agred, I suppose it really shows that no one driving force can be relied on for accuracy and has been said many times in the winter thread we must look at the 'bigger' picture. As far as I'm concerned that means looking beyond the planet too. Having said that I think GP and SB provide a very good service :blink:

BFTP

They are certainly good reads, full of knowledge, but there isn't a "service" that can forecast more than 3 weeks in advance, with an accuracy of even 3 in 4 (75%), which is what I'd need for it to be in any way useful......anywhere. Not even our good netweather people, the Met Office, NOAA, or Mystic Meg are presently capable of that!

Paul

Edited July 28, 2006 by Dawlish

[BrickFielder]

The hadley Center have had some particularly impressive results in being able to predict the NAO based on sea surface temperatures and snow and ice cover extents using the their latest climate model.

Hadcm3

More Hadcm3

Discussion on seasonal forecasting

[parmenides3]

Carinthian, the NW arctic 'guru', is away, but the sea ice conditions continue to change, so here is an update.

There is a noticeable change in colour on the ice analysis pages, indicating large areas where the ice concentrations have gone from the 80-100% range down to the 60-80% range, suggestion a substantial thaw in most areas.

The Anchorage ice desk reports that the high pressure area over the North coast is now moving Eastward and is being replaced by an area of low pressure, led by a front, coming in off the Bering Sea. Areas in the Beaufort area have cleared temporarily, but as they clear they are being filled again by the pack ice drift.

The SSTAs on the NOAA PSB/EPS images show orange/red across the entire Arctic, with the exception of cold spots around Novaya Zemlya and parts of the Kara and Barents Seas. Land temperatures on the Danish Met. site are warm across both main continental areas, and the general synoptic charts show mild conditions and relatively low precipitation almost everywhere, with the exception of the high Greenland interior.

Sea ice levels have dropped in the Arctic Basin by ~0.2 M KM2 and are about 10% lower than the same time last year. The Bering Sea, Hudson Bay and the Sea of Okhostsk all have nominal quantities of ice, almost all in isolated coastal pockets in bays and inlets. The amounts in all three areas are comparable to this time last year. There is still ice at the North end of the Baffin Sea, but only half the amount from 2005. The Greenland Sea shows little significant ice from the Denmark Strait Southwards and some fragmentation in the far North-West and, although current levels compare to last year's, maybe half of the remaining ice is at a reduced thickness.

Levels in the Barents sea are very low; at the moment they are near the level of last September's minimum. There is also half the amount of ice in the Kara Sea than July '05; around 0.13 M KM2 less. The situation is similar in the Laptev Sea, with levels down 0.15 M KM2.

In the East Siberian, Chuckchi and Canadian Archipelago levels are also lower, though at a less extreme level, though the net reduction compared to '05 is around 1.0 M KM2. In fact, only the Beaufort Sea currently contains a similar amount, if not slightly more sea ice, at ~0.32 M Km2; this is probably due to the movement mentioned above.

Cryosphere Today gives the overall figure for the Arctic as ~6.5 M Km2, an anomaly from the 1979-2000 mean of -1.3 M Km2, and lower than the same date in 2005. With the ice due to recede for another month or so yet, it looks very likely that the minimum this year will be comparable to the extremely low figure recorded in each of the previous three years, and almost certainly lower than either 2000 or 2001.

Ten days ago, I thought it unlikely that the record minimum would be equalled this year, but, on the evidence of the recent thaw rates, it is reasonable to believe that this is now possible, should conditions not alter substantially in the coming month. Hopefully, Carinthian and the other climate experts will provide their unquestionably more professional analyses in the weeks to come.

I hope this has been of interest.

[acbrixton]

thanks for taking the time to post this...

regards

ACB

[Dawlish]

thanks for taking the time to post this...

regards

ACB

Thanks P. I'm seeing the same from the cryosphere to day charts. Melting has speeded up in the last 2 weeks.

Paul

[oldsnowywizard]

with all the extra melt water has there been any indication of where this fresh water is drifting too? ie is it heading South from the arctic or is it just staying around there.. i guess the question really is is this increase in melt water having any affect on the salinity levels to the north of us and having any affect on the NAD? If the fresh water is just staying in the same postion then when it does get colder it will freeze faster surely?