ENSO Updates (2007 thru 2023)

[NDG]

With TAO and the weeklies having recently cooled 0.2+ and the July SOI headed for a sold +, I have no choice but to reduce the odds in my mind for an oncoming El Nino this year. Previously, I had said the chances were "very good".

If one wants El Nino, one cannot like how high Tahiti's SLP is going to end up this month. For 7/1-20. it is averaging 1015. I'm projecting it will approach or even reach 1019 tomorrow and still be near 1018 the day after. Here are my educated guesses for the rest of the month based on the 12Z models:

7/21: 1019
7/22: 1018
7/23: 1016.5
7/24: 1015
7/25: 1014.5
7/26: 1014
7/27: 1014.5
7/28: 1015
7/29: 1015
7/30: 1015

If the above projections were to come close to verifying, the full July 2017 Tahiti averaged SLP would come out to ~1015.2, which is a full mb above the longterm average for all years since 1950. That 1015.2 may even be a little conservatively low as the EPS would imply that it get up to ~1015.35. Here are some Tahiti averages for various oncoming ENSO:

Strong Nino: 1013.4
Weak to Mod Nino: 1013.9
Weak to mod Nina: 1014.3
Strong Nina: 1015.2

So, Tahiti's 2017 SLP is now projected to come in near the average for an oncoming strong La Nina. As a matter of fact, every single instance of Tahiti being 1015.0+ in July since 1950 (8 of them) was an oncoming La Nina year. OTOH, every single one of those 8 cases had an AMJ trimonthly Nino 3.4 that was negative vs 2017's +0.5. So, I'm not at all saying it means we're likely headed for La Nina. But I am saying that the chances for El Nino have dropped quite a bit in my mind over the last month. Consider this: for every El Nino since 1950 that was oncoming (24 of them), Tahiti's SLP was never higher than 1014.7!

After being too low at Tahiiti by ~1 mb/day for the first few days, the last few days have come in higher by over 1 mb/day. Translation: the full July, 2017, average Tahiti SLP is once again aiming for a very unfriendly to El Nino ~1015.2.

Not only that but July will end up close to La Nina SOI threshold after the 30 day average started the month at -9.57 it has done almost a 180 deg turn in just 30 days.

[Kingarabian]

Yeah all eyes on the first two weeks of August at this point. If they average near 1015 at Tahiti, then it'll be El Nino cancel since the MJO is parked near Darwin.

GFS and Euro are currently all over the place with the MSLP at Tahiti for the first week. Euro did show August 6th or 7th at 1011mb though.

[dexterlabio]

Yeah all eyes on the first two weeks of August at this point. If they average near 1015 at Tahiti, then it'll be El Nino cancel since the MJO is parked near Darwin.

GFS and Euro are currently all over the place with the MSLP at Tahiti for the first week. Euro did show August 6th or 7th at 1011mb though.

I thought the MJO staying in the Pacific aids in spreading sea surface warmth from west to east, thus boosting El Nino chances? Or should the MJO make a faster and more pronounced counter-clockwise turn from Phase 6 to Phase 8?

[Kingarabian]

Yeah all eyes on the first two weeks of August at this point. If they average near 1015 at Tahiti, then it'll be El Nino cancel since the MJO is parked near Darwin.

GFS and Euro are currently all over the place with the MSLP at Tahiti for the first week. Euro did show August 6th or 7th at 1011mb though.

I thought the MJO staying in the Pacific aids in spreading sea surface warmth from west to east, thus boosting El Nino chances? Or should the MJO make a faster and more pronounced counter-clockwise turn from Phase 6 to Phase 8?

If it stays over the maritime continent for an extended period of time, it makes pressures lower than normal there and pressures over Tahiti rise.

High pressure over Darwin and normal or lower pressure at Tahiti increases divergence at the equator thus relaxing the easterlies.

[dexterlabio]

If it stays over the maritime continent for an extended period of time, it makes pressures lower than normal there and pressures over Tahiti rise.

High pressure over Darwin and normal or lower pressure at Tahiti increases divergence at the equator thus relaxing the easterlies.

Wow makes a lot of sense to me, thanks for the info. So the MJO staying in MC strengthens the easterlies and promotes convection over the area, all main characteristics of La Nina. It's interesting how one month can make a huge difference, from a hefty chance of El Nino to growing chances of La Nina. Though I believe the coldest the ENSO state this year could be is cold neutral, similar to 2013, except for the consistent +PDO pattern we're seeing this year.

[Kingarabian]

On its last straw or here comes the Nina.



Gonna be an important week from the SOI.

[cycloneye]

Looks like the weekly update of CPC will have Nino 3.4 go down to 0.0C.

[Kingarabian]

On its last straw or here comes the Nina.

[img]http://i.imgur.com/m1QsrRK.gif[/mg]

Gonna be an important week from the SOI.

00z Euro on queue lol, answers the call just in time and throws another curveball. For the first time in a month, it has the MSLP average at Tahiti from August 1-8 at 1013.75. Would equate to the SOI tanking again since Darwin's MSLP is around 1013.25 for August 1-8.

[Ntxw]

At the update later this morning will be 0C, that about does it for any El Nino from the weeklies

[cycloneye]

Text of CPC July 31 update that drops Nino 3.4 to 0.0C.No El Nino for the rest of 2017.

[weathaguyry]

Wow, SOI continues to rise, Nino region temps have plummeted, along with subsurface temps, MJJ may be able to sneak out a +.5 for the tri-montly, but if these trends continue I highly doubt that JJA will get a +.5 tri-montly

[NDG]

At the update later this morning will be 0C, that about does it for any El Nino from the weeklies

Yeah, like I said last week yet another El Niño fail after I saw the rapid cool down that started two weeks ago.

[LarryWx]

Not only did 3.4 plunge from +0.4 to 0.0, but the upper ocean heat content plunged nearly 0.5 from +0.3 down almost to -0.2! I'm now going with El Niño "cancel" after thinking just a month ago that El Niño had a very good chance. It isn't just that 3.4 is down to 0.0, but also the combination of a 1015.2 July SLP at Tahiti and the upper OHC plunging to negative. So, this is an epic fail on my part and reminds me of 1993 more than anything.

[Kingarabian]

At the update later this morning will be 0C, that about does it for any El Nino from the weeklies

So JJA won t make it?

[Ntxw]

At the update later this morning will be 0C, that about does it for any El Nino from the weeklies

So JJA won t make it?

If August sees dramatic warming it might but that is slowly slipping. It needs to warm and do it quickly

[Kingarabian]

At the update later this morning will be 0C, that about does it for any El Nino from the weeklies

So JJA won t make it?

If August sees dramatic warming it might but that is slowly slipping. It needs to warm and do it quickly

Would +0.5C be enough?

[weathaguyry]

So JJA won t make it?

If August sees dramatic warming it might but that is slowly slipping. It needs to warm and do it quickly

Would +0.5C be enough?

I belive it would have to get to +0.5C pretty soon and hold it to get +0.5C for the JJA tri-monthly

[Ntxw]

So JJA won t make it?

If August sees dramatic warming it might but that is slowly slipping. It needs to warm and do it quickly

Would +0.5C be enough?

It needs to get back to 0.5C and then steadily rise through the month. I think Larry might be on to 1993

[Kingarabian]

Mantua Box average (from stormvistawx) for the past 30 days is near +0.80C, so I expect the PDO to remain put.

[cycloneye]

@philklotzbach
Eastern and central tropical Pacific equatorial upper ocean heat content anomalies have gone below-average for 1st time since April.

 https://twitter.com/philklotzbach/status/892163883766599681