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E.N.S.O. Discussion


Gray-Wolf

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

It's possible that the weeklies could peak at moderate but i suspect a weak Nino is more likely overall.

The new weeklies are at -0.2 and 0.2 due to a recent trade burst so we won't get a 0.5+ ONI figure before September in all likelyhood. 

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Interesting to see just how stubborn 1.2 is being..

4A8707B9-BC39-4368-B9C6-4738BBE6744E.png

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  • 2 weeks later...
Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl
On 21/07/2018 at 11:21, sebastiaan1973 said:

Yes interesting reading, others are saying we are moving into an El Nino situation. Noting the composite years, 1995 stands out, this year has been quite similar to 1995 so far, with the change in March, the dry theme being very comparable since April and anomalous warmth, Aug 95 was exceptionally dry, warm and sunny, however, we had a wet Sept followed by a further dry period warm in Oct but colder in Nov with a cold snowy winter..

The synoptics show high pressure to the north and low pressure to the south for the winter.. 

Also 1995 was close to solar minima as well.. 

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Posted
  • Location: Hadleigh, Suffolk
  • Weather Preferences: An Alpine climate - snowy winters and sunny summers
  • Location: Hadleigh, Suffolk

"Look South, ENSO Forecasters"

Prof. Jason Furtado has just written a very interesting 'guest article' for the NOAA/Climate.gov website giving details of his research into the role that the South Pacific Oscillation (SPO) plays in helping determine the type and strength of developing EL Ninos. The article includes many informative charts.

Key extracts:

......let’s consider the evolution and development of an El Niño event. In June when an El Niño event is developing, warm water anomalies are already present in the central tropical Pacific. For development to continue, those warm central tropical Pacific SSTs have to build eastward and amplify during Northern Hemisphere summer and early fall. This eastward propagation of anomalies is driven by westerly winds and the formation of Kelvin Waves in the ocean in the eastern tropical Pacific, thus allowing waters to get warmer there. Since the SPO modulates the strength of the South Pacific trade winds in the eastern tropical Pacific, and it is most active during JJA, the phase and magnitude of the SPO can either help or hurt those Kelvin waves and the winds during the critical growth phase for ENSO.

If the SPO is in the positive phase (i.e., a weaker South Pacific subtropical high), then the southeasterly trade winds weaken, which reduces the cold-water upwelling in the eastern tropical Pacific and allows for easier eastward propagation of the warm waters from the central tropical Pacific to the eastern tropical Pacific.

However, if the SPO is in the negative phase (i.e., a stronger South Pacific subtropical high), then the southeasterly trade winds intensify, and the cold-water upwelling in the eastern tropical Pacific also increases. These two factors create an environment hostile for eastward expansion of the warm waters. Thus, the warm SST anomalies tend to remain in the central tropical Pacific.

.......we identified all El Niño events (regardless of flavor) from 1950-present and then examined what the magnitude and sign of the JJA SPO was for that year. Using only that information, we predicted what the flavor of that El Niño event would be the following winter. The results indicate that our simple prediction scheme correctly predicted the flavor of the event nearly 3 out of 4 times.

What does the SPO have to say about the expected flavor of this year’s El Niño event? The figure above illustrates that the SST warming thus far over the eastern tropical Pacific is spotty with evidence of subsurface warming present. Note that south of the Equator, however, there is an expanse of quite cold waters. More importantly, the SLP pattern in the South Pacific resembles a negative SPO signature. Indeed, for June 2018, the SPO index was about -1.3, and the SLP anomaly pattern in the South Pacific thus far for July also suggests a negative SPO value for the month. Without a substantial turnaround for the SPO in August, the JJA SPO for 2018 could turn out negative. Thus, based on what I argued above, if an El Niño event forms this upcoming winter, it will most likely be a weak/CP El Niño event. Luckily, I am not totally alone in this prediction. The latest forecast from the NMME models (below) hints at a weaker/CP El Niño event evolving this winter.

1441320207_SSTForecastforOND2018NMMEinJul2018.thumb.jpg.affe872321dee7d06cd22697553b4c7f.jpg

Full article: https://www.climate.gov/news-features/blogs/enso/look-south-enso-forecasters

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Warming should occur in August based on the forecast pattern but the trade burst for the first two thirds of the month did some damage. 

TAO_5Day_EQ_xz.gif

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Nino 1.2 has finally gone positive. Both 1.2 and 3.4 are at 0.1.

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Things may change because we do have a Nino standing wave around the dateline atmospherically but this is not going to plan, we have taken a step backward with the lack of westward moving westerly wind bursts since June. 

This has not gone to plan..

TAO_5Day_EQ_xz.gif

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Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

It's a curious one, this El Nino, as the atmosphere is now more engaged with that mode than the ocean. Variations like this are why you don't tend to see much in the way of significant relationships between weak ENSO events and the patterns across the N. Atlantic and Europe; the atmospheric setup is free to cycle more between Nino-like and neutral, sometimes even slightly Nina-like. Hence foreseeing the timing and magnitude of these cycles becomes important.

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Atmosphere thinks its in Nino because of the large waves in April and May plus the central pacific events just gone.

 

If there's no reinforcement or we get easterlies then we could still have a dud. As it is, its hard to see past weak.

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

The recent westerly wind burst has helped and we can see a few posts up that a narrow warm layer at the surface has developed so i expect the latest figures to tick up a bit. The problem for Nino is that we are about to see a sizeable trade burst over the zone so in a week or so that will have probably bee destroyed. 

The wider Pacific picture shows well how we are seeing the classic subdued Indian Ocean/Indonesia picture with a warm west Pacific but it's not as responsive as it could/should be in the central and east. We can also see a lightly negative -PDO which may a factor fighting against it. 

cdas-sflux_ssta_global_1.png

 

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Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

For what it's worth, I believe GFS is going too far with holding up the MJO and increasing those trade winds.

u.anom.30.5S-5N.gif

Today's update is not as brutish as yesterday's but it's still got the MJO stuck up against a brick wall which seems OTT for a weakly positive SST pattern and with the suppression phase of the CCKW having departed by then.

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  • 2 weeks later...
Posted
  • Location: Netherlands
  • Location: Netherlands
Posted
  • Location: Netherlands
  • Location: Netherlands

http://easternmassweather.blogspot.com/2018/09/potential-weak-moderate-el-nino-analogs.html 

Update. A nice read. "Currently, we here at at Eastern Mass Weather favor a weak el nino NDJ peak ONI value of approximately +.9C with a moderately strong modoki value of around .4."

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Posted
  • Location: Roznava (Slovakia) formerly Hollywood, Co Wicklow
  • Weather Preferences: continental climate
  • Location: Roznava (Slovakia) formerly Hollywood, Co Wicklow
On 05/09/2018 at 12:27, sebastiaan1973 said:

http://easternmassweather.blogspot.com/2018/09/potential-weak-moderate-el-nino-analogs.html 

Update. A nice read. "Currently, we here at at Eastern Mass Weather favor a weak el nino NDJ peak ONI value of approximately +.9C with a moderately strong modoki value of around .4."

Some of those analogue EL Nino Modoki  winters  like 1979/08,2006/07,2014/15 were terrible winters here and in Europe, stronger EL Nino like 2009/10 would be better for us then.

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Posted
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)
  • Weather Preferences: Sunshine and 15-25c
  • Location: Edmonton Alberta(via Chelmsford, Exeter & Calgary)
23 hours ago, knocker said:

 

The way things or trending..and the fact it seems el nino is struggling to get going...i wouldn't be surprised if we end up with ENSO neutral winter

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington
Quote

There's a 70% chance of a recurrence of the El Niño weather event before the end of this year, according to the World Meteorological Organisation.

The last El Niño occurred in 2015-16 and impacted weather patterns around the world.

Researchers say they are not expecting this new one to be as intense as 2015-16.

According to the WMO, climate change is influencing the traditional dynamics of these weather events.

The El Niño/Southern Oscillation, to give its proper title, is a natural event that involves fluctuating ocean surface temperatures in the Pacific, which influence the weather all over the world.

The 2015-16 El Niño was one of the strongest ever recorded, and had an impact on global temperatures, which saw 2016 enter the record books as the warmest year.

1

https://www.bbc.co.uk/news/science-environment-45471409

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Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.
24 minutes ago, Paul_1978 said:

Am I right in thinking that El Nino (or La Nina) has little, if any, impact on the weather in Europe?

IMO ENSO is one of those effects that, when viewed in retrospect, nearly always seem to fit expectations; however, when looked upon from a predictive viewpoint, such effects have much less value...?

And (also only IMO) the ENSO effect can, and usually is (in our far corner of the world) swamped by things that occur much nearer to home...

Then again, maybe someone like BFTV or Glacier Point would be better placed to answer your question than me?

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Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

In the broadest possible sense, ENSO phases encourage certain weather patterns to occur more often then others, but still within a cycle of patterns that means monthly means tend not to capture the relationship (let alone seasonal means!) and even weekly means can struggle unless they're very accurately selected. 

On top of that, there are shifts from one month to the next owing to the ever-changing thermal gradient magnitudes and patterns, as the seasons interchange and yes, interference from other phenomena can also result in short-term variations on the theme.

It really is no wonder that weather forecasting is such a demanding business and one that has to allow for quite a lot of error beyond 4-5 days range (and sometimes even within that).

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