Sea Surface Temperatures

[summer blizzard]

Looks like La Nina is now in full swing again

MEI values were actually at -0.5 in August meaning weak La Nina although it does not become official until tri-monthly observations are below -0.5.

[damianslaw]

Anyone know what effect the impending high pressure will have on SST's. Suspect it will help maintain warm SST's over the N Sea, but also cool SST's over the N Atlantic thanks to cooler airflow from the west here.

[summer blizzard]

Anyone know what effect the impending high pressure will have on SST's. Suspect it will help maintain warm SST's over the N Sea, but also cool SST's over the N Atlantic thanks to cooler airflow from the west here.

When it comes to the ocean, you tend to see low pressure upwell cooler water and high pressure warm water.

Locally it may raise them a little but not really important in the grand scheme.

[summer blizzard]

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

It looks as though there could be an Alaskan Vortex setting itself up which could be problematic during periods of +AO as it forces a -PNA signiture which enhances the mid-lattitude westerlies although during -AO periods it does lend itself to northerlies.

In the rest of the Pacific the Jet Stream actually looks very week with a mean ridge over the western Pacific and south eastern Pacific although as refreeze commences, the thermal gradiant will no doubt enhance over the western Pacific.

In the Atlantic there is indeed a tripole developing which lends itself to a -NAO period.

On that basis and given lag time, i would say that we may get a north westerly period between the 15th and 25th October.

[ZONE 51]

Comparing sea surface temperatures to last year around this time in October,

- large size

- small file

The Atlantic shown as a colder surface this year, North sea has areas or less cold,

If we zoom into the area of Atlantic you can sea where the orange shades this time last year appeared, and the colder blue areas this year,

This indicates some colder sea surface temperatures which affect the weather systems, when Ex hurricanes move across they bring tropical air mass which mixes with colder airmasses allowing for an strong low pressure or storm to continue its progress, but i would think the low pressure systems that form from non-tropical or ex-hurricane system would be less powerful due to colder sea surface areas and make for colder updrafts affecting the production? i would like some thoughts on this, some where saying the Atlantic is quite this year, i think it has less deep lows, normally we can get storms/gales battering the south, but they run across the north so far.

Edited October 31, 2011 by ElectricSnowStorm

[summer blizzard]

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

This one is more detailed in my opinion and offers a different story.

You can see La Nina in the Pacific along with a positive anomaly allied to a negative anomaly (-PNA signature) and a warm Atlantic but with the warm anomalies south of the UK and a cooler strip around our latitude.

I think the Jet Stream/lows are actually fairly strong, it is just that it is fairly far south and stalling to our south west.

[ZONE 51]

It does not look as cold on that one SB, around the north Atlantic shows a colder area but not as much as the charts i posted just now, so why are they different do you think? thanks.

Edited October 31, 2011 by ElectricSnowStorm

[summer blizzard]

I would assume that the same sattelite gets the data, they must just have different resolutions or interpret it different. Same as the models.

[cyclonic happiness]

I would assume that the same sattelite gets the data, they must just have different resolutions or interpret it different. Same as the models.

Yeah like adding a degree or two here and there.............I really don't know what to believe any more! http://hw.nwstatic.co.uk/forum/public/style_emoticons/<#EMO_DIR#>/unsure.png

[ZONE 51]

Yeah like adding a degree or two here and there.............I really don't know what to believe any more! http://hw.nwstatic.co.uk/forum/public/style_emoticons/<#EMO_DIR#>/unsure.png

We need to know if that area of Atlantic really has cooled earlier or more than last year and why, i know it was mild at first last year, and it is this year, so the only thing that it could be is melted ice causing fresh water to flow into the salty ocean water, this then causing cold areas of surface which would show on the temperature map, this then could cause a distruption of the Gulf Stream? need to look into this as i have read that colder sea areas around Greenland would disrupt the Gulf Stream-only if it was from melted ice.

It appears on the map that it really is getting colder in those areas!

map from NOAA so accurate as can be i would imagine..

http://www.osdpd.noa...st/contour.html - Sea Surface Temperatures NOAA

Edited November 1, 2011 by ElectricSnowStorm

[summer blizzard]

Comparing last years, the Pacific looks similar but the Atlantic the opposite...

Last year had a diffluent signal in the Atlantic supporting higher than average pressure.

This year has a convergant signal in the Atlantic supporting low pressure.

Neither is nessesarily good or bad, but it may lend support to GP's notion of blocking over Scaninavia.

[ZONE 51]

This is the area of interest,

This shows that it is a colder current, but how cold is normal and is it colder then its meant to be? if it is then is it melted ice causing it to cool down, this would be fresh water that causes problems with the gulf stream.

Or was it warmer then normal last year!

Edited November 1, 2011 by ElectricSnowStorm

[summer blizzard]

I can't be sure but i think that the Labrador current is actually a deep water current (theres another small sinking zone in that area). If this is so then the temperature at the surface is largely irrelevant as the main surface current sinks east of Greenland.

The area in question was indeed much warmer than normal at the surface last year.

I suppose that even with a signal for Atlantic troughing since there seems to be a much lower thermal gradiant this year then we may still get good heights over Greenland.

[BornFromTheVoid]

Here's an animated GIF showing the changes in SSTAs since the beginning of July. I exceeded my bandwidth or something on photobucket so can't link to it. Just click on the image and the animation should load up in a few seconds. (2.9MB)

Edited November 6, 2011 by BornFromTheVoid

[summer blizzard]

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

Today's as well..

Alaskan cold anomaly is connecting with La Nina which is good in terms of amplification over the USA, we also seem to be getting an W/E split in the Atlantic.

[ZONE 51]

Thanks SM, ive taken the image from the link you provided and posted it.

Edited November 7, 2011 by ElectricSnowStorm

[BLAST FROM THE PAST]

I've been mantioning the SSTs on other threads. Knew there was one but couldn't find it. This current set up shows the La Nina weaker at this stage but possibly a stronger or at least as strong -ve PDO. It also shows more cold SSTs in the arctic regions. We did see a large drop of Global temp anomaly in Oct back towards average temp and looking at the way the SSTs continue to fall I suspect another drop come end of Nov. I think the NH is in for widesrpead cold conditions......except the UK. http://hw.nwstatic.co.uk/forum/public/style_emoticons/<#EMO_DIR#>/smiliz39.gif

BFTP

[ZONE 51]

I've been mantioning the SSTs on other threads. Knew there was one but couldn't find it. This current set up shows the La Nina weaker at this stage but possibly a stronger or at least as strong -ve PDO. It also shows more cold SSTs in the arctic regions. We did see a large drop of Global temp anomaly in Oct back towards average temp and looking at the way the SSTs continue to fall I suspect another drop come end of Nov. I think the NH is in for widesrpead cold conditions......except the UK. http://hw.nwstatic.co.uk/forum/public/style_emoticons/<#EMO_DIR#>/smiliz39.gif

BFTP

The deepest block of cold ever will sit there all winter just to annoy cold fans http://hw.nwstatic.co.uk/forum/public/style_emoticons/<#EMO_DIR#>/laugh.png Edited November 9, 2011 by ElectricSnowStorm

[summer blizzard]

The tripole developing in the western Atlantic could be interesting.

Signs that the jet may weaken?

Also, just look how negative the PDO is.

[BLAST FROM THE PAST]

The tripole developing in the western Atlantic could be interesting.

Signs that the jet may weaken?

Also, just look how negative the PDO is.

Signs that the jet will track southwards? not that it is north at the moment, just very meridional. That PDO -ve phase is strengthening and I think that the cold SST anomaly will bring a large Global temp anomaly drop end of the month like it did last month. This is looking like a big big NH winter coming.

BFTP

Edited November 11, 2011 by BLAST FROM THE PAST

[summer blizzard]

In terms of the northern hemisphere as a whole i definitely agree due to above average snowcover.

[Gavin P]

Anybody know whats going on with La Nina? It appears to have weakened quite a bit this week? Is this a temporary pause? Or have we had an early peak?

Now;

http://www.weather.u...ce/sst_anom.gif

Vs

A week ago;

http://www.weather.unisys.com/archive/sst/sst_anom-111106.gif

Edited November 12, 2011 by Gavin P

[summer blizzard]

Waxing and waning is to be expected when looking on a daily/weekly basis.

It is highly likely that both November and December will record moderate MEI La Nina values (i expect a December peak with a fairly quick weakening).

[summer blizzard]

I firmly believe the current high over western europe will sit there providing blocking but nothing more for the Uk for quite some time.

It may reoccur (sea surface temperature anomalies do support it for late November into early December) but in the medium term, we see a more normal zonal pattern with good ensemble agreement.

The Pacific cold anomalies have now joined up with would indicate a very amplified Jet Stream over the USA.

We really need the Atlantic tripole to expand further east.

[Weather-history]

Question: why does La Nina seem to last longer than El Nino?

For instance there was a La Nina that lasted from mid 1973 to mid 1976 but you won't find an El Nino of that length

Edited November 13, 2011 by Mr_Data