Sea Surface Temperature And Sea Ice Trends

[summer blizzard]

Glacier Point, the WPO value is only set to be slightly negative with signs of a rebound to positive again for the beggining of June.

http://www.cdc.noaa.gov/people/gary.bates/tele/wpo.gif

I think the key thing is the PNA, should this be positive, then there will be blocking in Canada however a negative PNA would favour a unsettled north easterly pattern.

Edited May 14, 2006 by summer blizzard

[Glacier Point]

SB,

the warm central western Pacific and cold anomalies to the north are a strong indicator of a positively orientated WPO to come in approximatley 4-5 weeks time.

This is likely to be a key player in developing a strong jestream over the western Pacific which will likely decelerate when it hits the cold anomalies over the eastern Pacific.

My strong suspicion is that this will be a recurring Summer pattern with the development of a large ridge into Alaska, a bifurcated Pacific Jet, a large trough off the western coast of America and a considerable downstream ridge giving a secondary trough over the eastern USA.

This pattern is evident in the current jet forecast:

http://wxmaps.org/pix/hemi.jet.html

GP

[summer blizzard]

Looking at the sea surface temperature anomoly chart, i must say that the outlook still looks fairly zonal, albeit warm with high pressure over Europe and low pressure over the north of the British Isles, in summary the outlook is zonal until at least the middle of June.

[Glacier Point]

Well the Oceans of the Northern Hemishphere really are studded with interest.

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

Of note are:

1) The very cold anomalies off eastern Siberia overlying warm anomalies likely to stoke up the west Pacific jet and continue its displacement northwards;

2) The very cold anomalies in the eastern Pacific likely to continue the highly amplified pattern and mean trough off the west coast US;

3) The developing warm anomalies off the western US likely to shift the mean trough westwards slightly increasing the probability of an east coast trough.

4) The Atlantic, oh boy, a band of cold water stretching from Bermuda to Lisbon overlain by a strong couplet of warm anomalies to the NW off Newfoundland likely to induce mean mid-Atlantic ridge and persistence of height anomalies over Greenland as well as warm anomalies across the tropical Atlantic (increased tropical storm development)

If nothing else the prevailing fetch for the UK will be some 0.5 degrees lower than normal because of the long track of the cold anomalies to our south west (almost duping us into thoughts of NAD shutdown)

Plenty to keep an eye on in terms of the weather in the next 5 weeks when this lot really starts to take effect.

GP

Edited May 25, 2006 by Glacier Point

[Bottesford]

At a simple level - do warm seas form low pressure areas & cool seas form high pressure areas? If so we might expect a fair bit of blocking in our area and any low pressure intrusions to come in from our north-west (from the warm pool) giving a cooler spell of rain compared to s-west systems.

[Glacier Point]

At a very simple level, the reverse, although this is highly dependent on psoitioning relative to windward continental masses and other anomalies.

Hope this helps

[Bottesford]

So we'd be likely to see depressions forming to our south-west which, upon arrival, would be somewhat cooler than normal?

[BLAST FROM THE PAST]

So we'd be likely to see depressions forming to our south-west which, upon arrival, would be somewhat cooler than normal?

Bottesford

It would certainly keep LPs on a more southerly track than normal and may well keep the AZH flat preventing any prolonged northward migration. Some including myself have generally pointed at a late summer with June AND July nothing to write home about with lengthy periods of 'diappointing' weather. It will be interesting to see later in the season with a very very active troipical storm/hurricane season which could well lead to very warm temps late inthe summer (Sept!!) but of course the track will be all important...could get pretty interesting

BFTP

[Bottesford]

So somewhat like last year with summer lasting almost to November! Think we skipped autumn last year going straight to winter. Those ex-hurricanes are great at pumping the heat up - so long as they stay out in the Atlantic.

[Rollo]

Sorry for being a bit picky but that is a whole week of cooler easeterlies Anyway for the record I warmth won't return before 20th after this weekend so I am going for 2/3 cool.

BFTP

Sorry about this but I must have pressed the wrong button.

Edited May 25, 2006 by Rollo

[Dawlish]

Yes a late summer lasting well into the autumn then plunging straight into winter with biting easterlies and heavy frequent snow showers with drifting

Tamara

Then we'd be living in Utah, Tamara!

*>))

[BLAST FROM THE PAST]

Then we'd be living in Utah, Tamara!

*>))

Maybe this switch many of us have alluded to will allow the UK to be more 'continental'

BFTP

[Dawlish]

Maybe this switch many of us have alluded to will allow the UK to be more 'continental'

BFTP

I don't believe there will be any "switch". Even with GW, the changes for the UK (insignificant, on a global scale remember - we don't really exist, despite posters thinking we actually count!) will be slow, with ample opportunity to buck the warming trend. Chaos rules, but even chaos must bend to the will of warmer global temperatures in the long term. Odds until then: 70% chance of June, the next month, the summer, 2006 and this decade being warmer than average; 20% chance of it not; 10% chance of it being within 0.25C of the long term average for your area.

"Switches" imply very quick changes in climate. I'm aware of the Greenland ice core research, but I'm also aware of the limitations of that research. I don't believe we are anywhere near a "switch" in climate in the North Atlantic. That is pure Hollywood, on the basis of current research data. we are not, nor will be in the short, or medium term, Utah.

Edited May 25, 2006 by Dawlish

[BLAST FROM THE PAST]

Sorry Dawlish you took the meaning of 'switch' wrong....maybe the term phase would be better ie longterm -VE NAO conditions for example with northern bloking the dominant theme

regards

BFTP

[Optimus Prime]

Quite extraodinary sea surface chart;

[Dawlish]

Sorry Dawlish you took the meaning of 'switch' wrong....maybe the term phase would be better ie longterm -VE NAO conditions for example with northern bloking the dominant theme

regards

BFTP

Sorry!

[BLAST FROM THE PAST]

Quite extraodinary sea surface chart;

Agreed!!

Dawlish no probs at all

BFTP

[AtlanticFlamethrower]

The track of the cold anomalies follows the track of the gulf stream. To the north - warm anomaly, to the south - cold.

Is it all the ice melting that is making the seas of the Northern Hemisphere so anomally cold at the surface?

[The PIT]

The track of the cold anomalies follows the track of the gulf stream. To the north - warm anomaly, to the south - cold.

Is it all the ice melting that is making the seas of the Northern Hemisphere so anomally cold at the surface?

I'm more interested in the Pacific.

[AtlanticFlamethrower]

I'm more interested in the Pacific.

That's what I was referring too with my melting ice comment.

What is the significance of that horse-shoe pattern? What's caused it?

[Dawlish]

With regard to the Arctic sea ice, the Areas North of the Atlantic are well below the average for the last 30 years. This is particularly the case in the Barents sea, where ice is only at 40% of the totals last May, which were themselves way below the mean. Ice in the Barents Sea is at record minimum amounts for May. The Greenland Sea is also well down on ice cover.

http://arctic.atmos.uiuc.edu/cryosphere/

The only area of the Arctic fringes (the Arctic basin and areas to the North of Russia are full of ice until about now when it begins to melt) which has had higher than average ice amounts, is the Bering Sea. This happened for the early part of the winter, until a melt in February and amounts now are well below the 30 year May mean. Perhaps this fits with the cold anomalies That BFTP has been pointing out. A significant amount of ice has melted quickly since February, to reduce the ice area from above the 30 year mean, to well below it in 3 months. I would imagine that this has added a more cold water to the Northern Pacific, than would be normal. If true, I'd expect the SSTs in the North Pacific to perhaps begin to recover soon.

Edited May 28, 2006 by Dawlish

[summer blizzard]

From looking at the sea surface temperature charts, it looks as though June will be dominated by the Azores High ridging into Europe which may produce hot plumes from time to time however it may also be unsettled from time to time.

[summer blizzard]

After looking at the archive charts, there is a pretty close match with last June, therefore we should see a similar first 20 days however with an interuption in the extra-tropical banding, rather than southerly interludes during the last third of the month, we should expect high pressure over the British Isles.

[Glacier Point]

only trouble is SB, the east Pacific anomalies are very different whilst the SSTA for early June 05 were felt during mid July onwards, which to my recollection was not great. A composite anomaly for the months leading up to June looks like this:

Jan-April 2005

Jan -April 2006

...the real differences being over the eastern Pacific which are likely to have significant downstream impacts on the UK IMO.

GP

[BLAST FROM THE PAST]

...the real differences being over the eastern Pacific which are likely to have significant downstream impacts on the UK IMO.

GP