ENSO Updates (2007 thru 2023)

[dexterlabio]

Correct me if I'm wrong, but if that SST configuration is maintained (especially around Nino 3.4) for another 3 months, then a weak El Nino can be declared? I'm not updated with the trimonthly values, but how many more months of >= 0.5C do we need to get five consecutive El Nino trimonthlies? I think the only thing we're watching for is if that surface warmth would be replaced by cooler patches, or if it will be able to sustain itself in the coming months.

[Ntxw]

Correct me if I'm wrong, but if that SST configuration is maintained (especially around Nino 3.4) for another 3 months, then a weak El Nino can be declared? I'm not updated with the trimonthly values, but how many more months of >= 0.5C do we need to get five consecutive El Nino trimonthlies? I think the only thing we're watching for is if that surface warmth would be replaced by cooler patches, or if it will be able to sustain itself in the coming months.

You need 5 consecutive trimonthlies. Sometimes they will declare a warning if only a trimonthly or two if there was strong confidence and the readings are heading well above 1C it seems given the slow nature of warming and cooling. In weak events, such as 2014, there are lots of bumps but they will declare after the 5 trimonthlies. They had many doubts about that one but because the readings clipped 0.5C long enough they had to. There are reverse cases too like 2012 where they wanted to declare but did not last long enough.

[NDG]

During the past week western Nino 3 has cooled down while Nino 4 has warmed up, over all 3.4 should come down to at least + 0.5C if not to + 0.4C on tomorrow's update. IMO.

[LarryWx]

The 12Z Euro suggests that the Darwin MTD SLP 6/1-21 will fall back to ~1013.5 from the ~1014.25 for 6/1-15 due to SLP's averaging only ~1012 for 6/16-21. OTOH, the 12Z GFS keeps it up near 1014 for 6/1-21 due to ~1013.5 for 6/16-21. The key I've been focusing on for June as a whole is whether or not it ends up 1014+ as that would be a pretty strong indicator of El Nino later this year based on June Darwin SLP history since 1951. Whereas the 12Z GFS through 6/21 suggests that is a very real possibility with only 1014 being needed 6/22-30, the 12Z Euro suggests that would be quite the challenge as it would mean that 1015 would be needed 6/22-30.

Generally, the Euro is a more accurate model than the GFS though I really don't know for just this specific area. I'll be closely following what the model trend is for the next few days of runs for 6/16-21 to see if it is heading closer to the lower SLP Euro or if it is heading closer to the higher SLP GFS.

Looking at runs just 24 hours later, whereas today's 12Z GFS is still near the 1013.5 mb it was at yesterday in its 12Z run for Darwin for 6/16-21, today's 12Z Euro has risen to near 1013.25 from yesterday's ~1012 for 6-16-21. So, the lower SLP Euro of yesterday has already risen almost all of the way to the higher SLP of the steady GFS. So, now there is pretty good agreement that Darwin will be ~1014 for 6/1-21. I've been focusing on the pretty rare 1014+ for June as a whole as being a pretty significant indicator for an oncoming El Niño if it were to be attained based on 1951-2016 June Darwin SLPs. If June ends up 1014+, I'd be near 75-80% chance for El Niño oncoming. I'll continue to follow.

[BigA]

The UKMO ENSO forecasts for June came out today (at least one their web site). In the forecast, the trend of the ensemble mean continues toward ENSO-neutral conditions during the heart of the hurricane season. There are still some members that predict El Niño during the ASO period.

June forecast


May forecast

[Kingarabian]

Should be down to +0.5C tomorrow since the BOM has 0.48.

[Ntxw]

Update will.be 0.4C when it comes out. Nino 1+2 is -0.1C

[weathaguyry]

Update will.be 0.4C when it comes out. Nino 1+2 is -0.1C

Wow! Nino 1+2 is below 0!

[Ntxw]

Update will.be 0.4C when it comes out. Nino 1+2 is -0.1C

Wow! Nino 1+2 is below 0!

It's the first weekly negative reading since November for 1+2

[cycloneye]

CPC weekly update that has Nino 3.4 down to +0.4C and Nino 1+2 down to -0.1C.

[Kingarabian]

LongPaddock still hasn't added the daily SOI value for yesterday. With the numbers I averaged out, 1014.22 @ Tahiti, and 1014.90 @ Darwin, it would come in around -22.00. LongPaddock sometimes usually slightly different pressures so it could be less, but it'll be -15 at minimum.

[LarryWx]

LongPaddock still hasn't added the daily SOI value for yesterday. With the numbers I averaged out, 1014.22 @ Tahiti, and 1014.90 @ Darwin, it would come in around -22.00. LongPaddock sometimes usually slightly different pressures so it could be less, but it'll be -15 at minimum.

Hey King,
A 1014.22 at Tahiti and a 1014.90 at Darwin would yield about -14 rather than -22. Is the -22 a typo?

[Kingarabian]

LongPaddock still hasn't added the daily SOI value for yesterday. With the numbers I averaged out, 1014.22 @ Tahiti, and 1014.90 @ Darwin, it would come in around -22.00. LongPaddock sometimes usually slightly different pressures so it could be less, but it'll be -15 at minimum.

Hey King,
A 1014.22 at Tahiti and a 1014.90 at Darwin would yield about -14 rather than -22. Is the -22 a typo?

You're right, that's what I was leaning on. That's what I was thinking since on June 10 it was:

Code: Select all

2017 161 1014.21 1015.05  -14.97

But in 2015:

Code: Select all

2015 284 1014.85 1014.85  -18.63
2015 285 1014.25 1014.90  -22.82

Are numbers from past years irrelevant to the current year?

[LarryWx]

LongPaddock still hasn't added the daily SOI value for yesterday. With the numbers I averaged out, 1014.22 @ Tahiti, and 1014.90 @ Darwin, it would come in around -22.00. LongPaddock sometimes usually slightly different pressures so it could be less, but it'll be -15 at minimum.

Hey King,
A 1014.22 at Tahiti and a 1014.90 at Darwin would yield about -14 rather than -22. Is the -22 a typo?

You're right, that's what I was leaning on. That's what I was thinking since on June 10 it was:

Code: Select all

2017 161 1014.21 1015.05  -14.97

But in 2015:

Code: Select all

2015 284 1014.85 1014.85  -18.63
2015 285 1014.25 1014.90  -22.82

Are numbers from past years irrelevant to the current year?

OK, I see the reason for the confusion. Yes, past years are relevant. But here's the key. Days 284 and 285 are from October. Each month has a different formula.

[Kingarabian]

Hey King,
A 1014.22 at Tahiti and a 1014.90 at Darwin would yield about -14 rather than -22. Is the -22 a typo?

You're right, that's what I was leaning on. That's what I was thinking since on June 10 it was:

Code: Select all

2017 161 1014.21 1015.05  -14.97

But in 2015:

Code: Select all

2015 284 1014.85 1014.85  -18.63
2015 285 1014.25 1014.90  -22.82

Are numbers from past years irrelevant to the current year?

OK, I see the reason for the confusion. Yes, past years are relevant. But here's the key. Days 284 and 285 are from October. Each month has a different formula.

Okay, thank you for your clarification. I see the differences now for each month.

[cycloneye]

Another month in postive for PDO as May PDO index is at +0.88C.

@bhensonweather
May PDO is +0.88, per Nate Mantua. That's an unprecedented 40th consec. month of positive PDO. Data go back to 1900

 https://twitter.com/bhensonweather/status/875415024755499008

[weathaguyry]

Same exact value as May 2004

[Kingarabian]

May PDO index is again positive at +0.88C.

 https://twitter.com/bhensonweather/status/875415024755499008

Yup. It's going to come in stronger for June as well.

[cycloneye]

No El Nino for thr rest of 2017 if this plume of all the models is right.

[Kingarabian]

Tug of war continues.

Relaxed easterlies have a WWB east of 120W have warmed the subsurface anomalies once again:

June 7:


June 12:


That cool pool will shrink once again as we saw in April/May with the SOI tanking and a WWB kicks off near the dateline. So expect Nino regions to be at weak El Nino levels until something changes in the grand scheme of things, and expect Nino 1+2, and Nino 3 to ramp up. There will be some oscillations here and there in the daily's, but the GFS and Euro continue to consistently show predominately >= -10 in the daily values for the entirety of their runs.