E.N.S.O. Discussion

[BornFromTheVoid]

Upper ocean heat content continues to climb, now at its warmest since April last year.

 

 

The warm kelvin wave continues to grow in strength, with a growing 5C+ anomaly and now a small 6C+ anomaly.

 

[BornFromTheVoid]

A powerful westerly wind burst ongoing and set to continue, which will continue to add to the increasing pool of warm subsurface waters in the equatorial Pacific.

 

 

With the MJO forecast to move into the region and become quite strong, there is plenty of potential for further westerlies and tropical activity, and a real possibility of a flip in the Walker Cell and transition to full El Nino conditions.

[BornFromTheVoid]

The February PDO value is in (2.3) making winter 2014/15 the most +ve PDO on record.

 

EDIT: Apparently the westerly wind burst I mentioned in my previous post is being touted by some as the strongest recorded since 1997...

Edited March 11, 2015 by BornFromTheVoid

[summer blizzard]

The February PDO value is in (2.3) making winter 2014/15 the most +ve PDO on record.

 

EDIT: Apparently the westerly wind burst I mentioned in my previous post is being touted by some as the strongest recorded since 1997...

 

Personally speaking i blame the PDO for our lack of a great winter, granted it could have been worse.

 

I believe it's the strongest in March since 97 but not the strongest per say.

[feb1991blizzard]

Yes that big fat high being there did for us completely, I wonder if the lack of anything resembling a tripole in the Atlantic knackered us as well.

[Gray-Wolf]

The February PDO value is in (2.3) making winter 2014/15 the most +ve PDO on record.

 

EDIT: Apparently the westerly wind burst I mentioned in my previous post is being touted by some as the strongest recorded since 1997...

 

Knocks posted this over on the Australia thread but it shows the WWB pretty well I think?

 

http://earth.nullschool.net/#current/wind/isobaric/1000hPa/orthographic=-213.90,-4.89,860

[feb1991blizzard]

Does anyone have any idea when we will revert back to a -ve PDO and what will it take, (surely only a blip looking at the last 50 year chart, we surely have a few years yet at least before we revert 'long term' to a +PDO again) and what will it take, will it take a strong La Nina event and the cold waters to push Northwards? I cant see any strong Northern blocking in winters until this is shifted, regardless of what solar / QBO combination, trouble is La Nina's don't fill me with confidence either anyway.

 

 

 

[Gray-Wolf]

Maybe you ought to set up a PDO thread Feb B? As it is we could well have reverted back into PDO positive as we had served long enough under the negative phase? We also need bare in mind the changes to the PDO since the 80's ( plenty of papers out there looking at the changes). As for today? well the triple R is not helping is it and if it is a product of low summer sea ice over the Pacific side of the basin then this particular Jet configuration can go on as long as the low ice forcing exists? We saw what low ice on our side of the basin did for our summers post 07' and prior to the 2012 slump in sea ice so we know that this type of forcing could be long term? 

 

Since the noughties we have lost around 10.5 million km of ice ( plus or minus 1 million due to 'weather') so a sub 14 million pack this spring doesn't bode to well for the 'average' loss come Sept?

[feb1991blizzard]

Maybe you ought to set up a PDO thread Feb B? As it is we could well have reverted back into PDO positive as we had served long enough under the negative phase? We also need bare in mind the changes to the PDO since the 80's ( plenty of papers out there looking at the changes). As for today? well the triple R is not helping is it and if it is a product of low summer sea ice over the Pacific side of the basin then this particular Jet configuration can go on as long as the low ice forcing exists? We saw what low ice on our side of the basin did for our summers post 07' and prior to the 2012 slump in sea ice so we know that this type of forcing could be long term? 

 

Since the noughties we have lost around 10.5 million km of ice ( plus or minus 1 million due to 'weather') so a sub 14 million pack this spring doesn't bode to well for the 'average' loss come Sept?

 

Cheers.

[Gael_Force]

Knocker posted an interesting blog about the Pacific SST patterns and it highlighted something I'd not heard of before. The North Pacific Mode (NPM) has given an alternative to traditional PDO pattern and ENSO.

 

 

 

I think this graph with the cold plunge of the NPM in '98ish probably gives credence to the PDO switch to cool at that time and that therefore we have maybe seen the negative phase complete after near twenty years.

 

I'd be very surprised if a decent Nino didn't get going this spring. If not, something has definitely messed with the traditional precursors.

 

http://climate.gov/news-features/blogs/enso/tropics-prime-suspect-behind-warm-cold-split-over-north-america-during

[knocker]

You may well be right GF

 

Evidence that the Atmospheric-Oceanic System is Evolving Towards a Strong El Nino

 

HEADLINES: There are a number of signs that suggest the atmosphere and ocean are working together in such a way that could produce a strong El Nino to emerge this Summer and continue into the cool season. Recency bias associated with last year’s El Nino event in the media mainstream would suggest here comes another early Spring El Nino hyping… but there has been enough evidence that suggests an El Nino event did in fact evolve late last Spring which continued through early Winter. This being said, there are now a number of global-scale observations that support evidence to put out a strong El Nino alert for the 2015 Summer and Fall Seasons. El Nino atmospheres during the Summer are often associated with a strong uptick in Pacific (West and East) tropical cyclone activity, a colder than average U.S. summer, and a reduced frequency of Atlantic tropical cyclones.

 

http://www.wsi.com/blog/energy/evidence-that-the-atmospheric-oceanic-system-is-evolving-towards-a-strong-el-nino/

[Midlands Ice Age]

Bumping this thread.

 

Has cyclone Pam had any major effect on this slow trend towards Nino?

 

It is a genuine question asked of our experts as I have heard nothing for 3 or 4 days.

 

I saw a chart on BBC weather a couple of days ago showing Pam moving just south of the equator and heading  towards North Island.

 

It also showed violent westerly winds across its northern flank, and extending for a maybe a couple of thousand mile northwards. . Would these have the effect of cooling the seas as per the northern hemisphere?  or would these westerly storms push GW's bulge towards the States enhancing the movement towards Nino? 

 

Anyone help?

 

MIA

Edited March 17, 2015 by Midlands Ice Age

[BornFromTheVoid]

Bumping this thread.

 

Has cyclone Pam had any major effect on this slow trend towards Nino?

 

It is a genuine question asked of our experts as I have heard nothing for 3 or 4 days.

 

I saw a chart on BBC weather a couple of days ago showing Pam moving just south of the equator and heading  towards North Island.

 

It also showed violent westerly winds across its northern flank, and extending for a maybe a couple of thousand mile northwards. . Would these have the effect of cooling the seas as per the northern hemisphere?  or would these westerly storms push GW's bulge towards the States enhancing the movement towards Nino? 

 

Anyone help?

 

MIA

 

There have been several tropical systems having an impact. These systems don't occur on the equator (no Coriolis effect), so they won't cool the ENSO regions. Their wind fields have contributed to strong westerly wind anomalies (possibly record strong) across the western equatorial Pacific, which will feed increasingly more warm water into the subsruface kelvin wave. This is warm water that naturally builds up in the west due to the trade winds and the Walker cell. The westerlies can be seen on the image below.

 

 

 

 

This is then leading to an increase in the upper ocean heat content over the area. When the warm kelvin wave surfaces, it will enhance the current Nino condition, possibly pushing this into being a longer lasting or moderate event.

 

[Nouska]

Bumping this thread.

 

Has cyclone Pam had any major effect on this slow trend towards Nino?

 

It is a genuine question asked of our experts as I have heard nothing for 3 or 4 days.

 

I saw a chart on BBC weather a couple of days ago showing Pam moving just south of the equator and heading  towards North Island.

 

It also showed violent westerly winds across its northern flank, and extending for a maybe a couple of thousand mile northwards. . Would these have the effect of cooling the seas as per the northern hemisphere?  or would these westerly storms push GW's bulge towards the States enhancing the movement towards Nino? 

 

Anyone help?

 

MIA

 

Excerpt from the BOM update.

 

 

The past fortnight has seen unusual conditions in the tropical Pacific, which may increase the chance of El Niño in 2015.

In the western Pacific, severe tropical cyclone Pam and tropical storm Bavi* straddled the equator, producing one of the strongest reversals in the trade winds in recent years. This change is expected to increase the already warm sub-surface temperatures currently observed in the tropical Pacific Ocean, which may in turn raise tropical Pacific Ocean surface temperatures in the coming months. However, it remains too early to say whether the reversal in the trade winds is a short term fluctuation or the beginning of a sustained trend.

 

http://www.bom.gov.au/climate/enso/#tabs=Overview

 

A very detailed look at current conditions for IOD and ENSO - somebody on SK2 has copy pasted from Wunderground but not provided link. BFTV, you seem very knowledgeable  - thoughts?

 

http://www.storm2k.org/phpbb2/viewtopic.php?p=2443050#p2443050

[Midlands Ice Age]

Thanks Nouska and  BFTV

 

So on balance, it is just about El Nino positive! 

 

Well be seeing shortly.

 

MIA

Edited March 18, 2015 by Midlands Ice Age

[knocker]

Regarding SST anomalies Ryan Maue has created a neat little comparison tool.

 

"Updated quick tool to compare current SST anomaly to last 30+ years ... freely available:

 

http://models.weatherbell.com/oisst/oisst_previous.php â€¦

[knocker]

Strongest MJO Event on Record Boosts El Niño Odds

 

The Madden Julian Oscillation (MJO) is a pattern of increased thunderstorm activity near the Equator that moves around the globe in 30 - 60 days, and has many important impacts on weather patterns world-wide. For example, when the area of increased thunderstorms associated with the MJO is located in a particular ocean basin, the odds of tropical cyclone formation increase there. Scientists use the Wheeler-Hendon MJO index to monitor how strong the MJO is, and this week, the amplitude of the MJO set a new all-time record for the strongest MJO event observed since record keeping began in 1974 (with no data available from 3/17/1978-12/31/1978 due to satellite problems). The MJO index hit 4.09 on March 15, 2015, beating the old record of 4.01 set on February 14, 1985.  On March 16, 2015, the MJO index set an even higher mark--4.67. That was likely the peak of this record MJO event, as the MJO index fell to 4.51 on March 17, and is forecast to drop significantly over the coming week. Thanks go to CSU's Phil Klotzbach for alerting me to the MJO record.

 

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2938

[Midlands Ice Age]

Strongest MJO Event on Record Boosts El Niño Odds

 

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2938

 

 

Knocks..

 

was this associated with cyclone  Pam?

 

I thought that most cyclones tended to drift north rather than south. why might that be?

[Gael_Force]

Knocks..

 

was this associated with cyclone  Pam?

 

I thought that most cyclones tended to drift north rather than south. why might that be?

Cyclones go poleward in their hemispheres. One north (anti-clockwise) of equator and one south (clockwise), doubly enhanced the west winds. Did you read the article,  it has a diagram.

 

[Gael_Force]

1and 2 warmed quite a bit in the last week.

 

[Midlands Ice Age]

Cyclones go poleward in their hemispheres. One north (anti-clockwise) of equator and one south (clockwise), doubly enhanced the west winds. Did you read the article,  it has a diagram.

 

 

Gael Force

 

Yep i had read it...

.

But my question was' do more cyclones move north than south'? and was the increase in MJO reported by Knocker directly related to this combination of cyclones.

 

I thought the MJO was a signal in the Western Pacific. Guess I must be wrong.

 

Don't think it mentions that in the text!

So I'll try again and make it really simple... (particularly for the person who 'liked' your reply)!!!

 

Are the conditions that caused the above unusual?

What is the balance between cyclones moving North or South in the Pacific?   I always thought more moved North, but that could be because more are reported hitting the larger land masses of China, Japan and SE Asia.

I am not an expert but I'm willing to learn.!!!

 

MIA

Edited March 19, 2015 by Midlands Ice Age

[BornFromTheVoid]

Gael Force

 

Yep i had read it...

.

But my question was' do more cyclones move north than south'? and was the increase in MJO reported by Knocker directly related to this combination of cyclones.

 

I thought the MJO was a signal in the Western Pacific. Guess I must be wrong.

 

Don't think it mentions that in the text!

So I'll try again and make it really simple... (particularly for the person who 'liked' your reply)!!!

 

Are the conditions that caused the above unusual?

What is the balance between cyclones moving North or South in the Pacific?   I always thought more moved North, but that could be because more are reported hitting the larger land masses of China, Japan and SE Asia.

I am not an expert but I'm willing to learn.!!!

 

MIA

 

The cyclones in the northern hemisphere tend to move north, and in the southern hemisphere they tend to move south (they move poleward). If they move toward the equator they fizzle out because they require the Coriolis effect to work, which doesn't work along the equator. Now, there tends to be more cyclones in the north Pacific than in the south, so they will inevitably tend to move north more than south.

 

I'm not sure what you mean by "I thought the MJO was a signal in the Western Pacific.". The MJO is a pattern of thunderstorm activity that circles the planet every month or 2. When it occurs in an area it can increase the risk of cyclone development, but isn't caused by the cyclones. The MJO has recently (by some measures) been at record strength in the Pacific, which would mean that these conditions are unusual.

 

All of these recent conditions may have contributed to a flip in the walker cell over the Pacific in the last few days. The Walker cell is where air rises in the western equatorial Pacific, moves eastward aloft and descends in the eastern Pacific, then move westward back to complete the circulation pattern. This low level westward (easterly) flow causing upwelling of cold water near Ecuador and piling up of warm water around Indonesia. In a classical El Nino scenario, this Walker cell is reversed and the pile of warm water sloshes back across the Pacific causing a large warm anomaly. The Walker cell has reversed in the last 5 days or so, but whether this will last or not remains to be seen. However, it it does remain reversed, we can expected the chances of a moderate to strong El Nino to grow rapidly.

[Gray-Wolf]

Well crunch time for the walker cell! with MJO shoving off from the region we will get to see if the reversal of the Walker Cell sticks and so begins to reinforce the ocean by driving more warm out across the regions.

 

To me the past couple of failed attempts fell at this point as the strength of forcing driving the enhanced trades was far greater than the forces looking for reversal of the cell and atmospheric compliance . Last year did look like it would flip but then moved back into the strengthened trades over summer. A year on and a year further away from the peak wind strengths we measured over the Tropical pacific so are we now primed for Nino?

[BornFromTheVoid]

Sharp rises in SSTs across all ENSO regions over the last week or so.

 

Nino 1 .................... .............................. ..................... Nino 2

 

 

 

 

Nino 3 ....................... ............................. ............................... Nino 4

 

 

Nino 3.4

 

 

The SOI has tumbled back well into Nino territory also (the more -ve, the more supportive of El Nino).

 

[Midlands Ice Age]

 

The cyclones in the northern hemisphere tend to move north, and in the southern hemisphere they tend to move south (they move poleward). If they move toward the equator they fizzle out because they require the Coriolis effect to work, which doesn't work along the equator. Now, there tends to be more cyclones in the north Pacific than in the south, so they will inevitably tend to move north more than south.

 

I'm not sure what you mean by "I thought the MJO was a signal in the Western Pacific.". 

The MJO is a pattern of thunderstorm activity that circles the planet every month or 2. When it occurs in an area it can increase the risk of cyclone development, but isn't caused by the cyclones. The MJO has recently (by some measures) been at record strength in the Pacific, which would mean that these conditions are unusual.

 

All of these recent conditions may have contributed to a flip in the walker cell over the Pacific in the last few days. The Walker cell is where air rises in the western equatorial Pacific, moves eastward aloft and descends in the eastern Pacific, then move westward back to complete the circulation pattern. This low level westward (easterly) flow causing upwelling of cold water near Ecuador and piling up of warm water around Indonesia. In a classical El Nino scenario, this Walker cell is reversed and the pile of warm water sloshes back across the Pacific causing a large warm anomaly. The Walker cell has reversed in the last 5 days or so, but whether this will last or not remains to be seen. However, it it does remain reversed, we can expected the chances of a moderate to strong El Nino to grow rapidly.

Thanks for the reply BFTV.

I guess I was confusing the SOI with the MJO. I didn't realise that the MJO was worldwide.

My original question was related to the number of cyclones moving north and/or south, as I was wondering whether possibly, this could act as mechanism for tranferring heat north or south across the equator. I know the net effect of these cyclones is thought to be negligible, but I just wondered whether there could be an effect of warming/cooling the SST's?, which if these cyclones are sustained might impact temperatures more widely?

MIA

Edited March 23, 2015 by Midlands Ice Age