ENSO Updates (2007 thru 2023)

[xtyphooncyclonex]

Let's see what would happen if the MJO arrives. The major climate model CFSv2 (the first to predict weakening and dissipation of the original record-breaking warm pool) currently shows the new warm pool rapidly growing in size and warming which it shows fueling a moderate-to-strong El Niño.

[dexterlabio]

Just looking ahead. Cool subsurface pool heading towards Niño 1+2 while Niño 3.4 & 4 start warming up.
Now that the SOI seems to finally stay negative we should see the central Pacific maintain some warmth, IMO.

We have yet to see if there will be weaker or stronger westerlies in the coming weeks and months. Stronger WWB's would transport more warmth well into the eastern Pacific (east Nino 3 and Nino 1+2 regions)...thus having a traditional type of Nino.. weaker westerlies could only transport warmth into the central Pacific.


IMO it will all depend on the MJO, if it will return to the Pacific with stronger signal and faster progression.

[somethingfunny]

We can put stock into all those maps of temperature anomalies that only show certain depth levels of the ocean or believe the daily meanderings of computer-generated SOI numbers, but to me it's pretty obvious that we have an El Nino going on, sometimes the proof is right in front of you:



I may just be simplifying things too much but, this just doesn't happen in neutral years.

[dexterlabio]

^I agree. This is a very rare and amazing feat even for an El Nino year... we don't see hurricanes travelling from EPAC to WPAC often, moreso hurricaneS threatening Hawaii all in one year...

[CaliforniaResident]

This summer screams "EL NINO" to me although the models are showing that we may fade to neutral by fall. We've experienced an extremely rare phenomenon in the L.A. area this summer. Anyone want to take a stab and guess what it is?(hint-it's something that's very common in the Eastern part of the U.S.)

[Yellow Evan]

This summer screams "EL NINO" to me although the models are showing that we may fade to neutral by fall. We've experienced an extremely rare phenomenon in the L.A. area this summer. Anyone want to take a stab and guess what it is?(hint-it's something that's very common in the Eastern part of the U.S.)

Rain.

What models show it fading by fall?

[CaliforniaResident]

This summer screams "EL NINO" to me although the models are showing that we may fade to neutral by fall. We've experienced an extremely rare phenomenon in the L.A. area this summer. Anyone want to take a stab and guess what it is?(hint-it's something that's very common in the Eastern part of the U.S.)

Rain.

What models show it fading by fall?

specifically, a summer thunderstorm (one actually on the beach itself killing one and injuring several others which has never happened here). We had one on the beach in July and also some light but significant (by L.A. standards) accumulation this past weekend
L.A. gets nearly all of it's measly 12 inches of rain a year from November through April.
Rain in late spring and early fall is unusual
Rain in mid-summer is almost unheard of in L.A. proper (although the mountains and deserts usually get a few storms during the monsoons).

I came across rumors the warm pool was fading (we've had warmer than normal SST all summer here) and was going to fade to neutral this fall (or a weak El Nino).

[Yellow Evan]

This summer screams "EL NINO" to me although the models are showing that we may fade to neutral by fall. We've experienced an extremely rare phenomenon in the L.A. area this summer. Anyone want to take a stab and guess what it is?(hint-it's something that's very common in the Eastern part of the U.S.)

Rain.

What models show it fading by fall?

specifically, a summer thunderstorm (one actually on the beach itself killing one and injuring several others which has never happened here). We had one on the beach in July and also some light but significant (by L.A. standards) accumulation this past weekend
L.A. gets nearly all of it's measly 12 inches of rain a year from November through April.
Rain in late spring and early fall is unusual
Rain in mid-summer is almost unheard of in L.A. proper (although the mountains and deserts usually get a few storms during the monsoons).

I came across rumors the warm pool was fading (we've had warmer than normal SST all summer here) and was going to fade to neutral this fall (or a weak El Nino).

That rumor is true, but we have a new warm poor building.

The warmer SST's is due to the +PDO signal.

[Ntxw]

Posted by Macrocane in one of the active CPAC/EPAC threads. Worth reposting here. Those raw westerly winds near the dateline (hello new warm-pool) certainly doesn't hurt the activity. MJO? Who needs it!

[cycloneye]

Climate Prediction Center August update

They now predict Weak El Nino by the fall thru early Winter.Not forecasting a Moderate to Strong one.

Over the last month, model forecasts have slightly delayed the El Niño onset, with most models now indicating the onset during July-September, with the event continuing into early 2015 (Fig. 6). A strong El Niño is not favored in any of the ensemble averages, and slightly more models call for a weak event rather than a moderate event. At this time, the consensus of forecasters expects El Niño to emerge during August-October and to peak at weak strength during the late fall and early winter (3-month values of the Niño-3.4 index between 0.5oC and 0.9oC). The chance of El Niño has decreased to about 65% during the Northern Hemisphere fall and early winter (click CPC/IRI consensus forecast for the chance of each outcome).

http://www.cpc.ncep.noaa.gov/products/a ... odisc.html

['CaneFreak]

Thanks cycloneye. They may be biting their tongue if this downwelling OKW continues to get stronger and we get a decent sustained WWB to accompany it.

[curtadams]

The models predicting an El Nino must already be implicitly predicting another Kelvin wave with winds to drive it across the Pacific. We certainly won't get an El Nino just with the rapidly fading warm pool we've got in the East Pacific now.

[xtyphooncyclonex]

The models predicting an El Nino must already be implicitly predicting another Kelvin wave with winds to drive it across the Pacific. We certainly won't get an El Nino just with the rapidly fading warm pool we've got in the East Pacific now.

Are you aware of the rapidly growing warm pool which the models were consistent about? The dissipation of the original warm pool was forecast by CFSv2 earlier this year, followed by growth of another warm pool which triggers the Niño.

[NDG]

I agree with the latest CPC forecast, a weak El Nino at this time looks more likely if not a low end moderate one.

[Ntxw]

If the TAO buoys are trusted, we have a good sized warm pool now below the surface across the Pacific. At the surface Nino 3 and 1.2 have warmed recently while 3.4 remains stubbornly lowest of the bunch however it too is warming. 1, even some 2C anomalies are appearing north of the equator between 0 and 5N around 120W

[NDG]

The reason why I agree with the CPC about now calling for only a weak El Nino to low end moderate by the Fall because if you look at the CFSv2 subsurface forecast, which many of you are giving credit for forecasting the current cool pool forecast surfacing in the eastern and central Pacific, it is forecasting the next subsurface warm pool to be not nothing close as warm as the warm pool earlier in the Spring.

[Ntxw]

Haven't posted to maps in awhile. Here are some of the latest.










MEI*

2014 -.318 -.269 -.017 .152 .932 .878 .815


*Here we attempt to monitor ENSO by basing the Multivariate ENSO Index (MEI) on the six main observed variables over the tropical Pacific. These six variables are: sea-level pressure (P), zonal (U) and meridional (V) components of the surface wind, sea surface temperature (S), surface air temperature (A), and total cloudiness fraction of the sky (C). These observations have been collected and published in ICOADS for many years. The MEI is computed separately for each of twelve sliding bi-monthly seasons (Dec/Jan, Jan/Feb,..., Nov/Dec). After spatially filtering the individual fields into clusters (Wolter, 1987), the MEI is calculated as the first unrotated Principal Component (PC) of all six observed fields combined. This is accomplished by normalizing the total variance of each field first, and then performing the extraction of the first PC on the co-variance matrix of the combined fields (Wolter and Timlin, 1993). In order to keep the MEI comparable, all seasonal values are standardized with respect to each season and to the 1950-93 reference period.

[dexterlabio]

The reason why I agree with the CPC about now calling for only a weak El Nino to low end moderate by the Fall because if you look at the CFSv2 subsurface forecast, which many of you are giving credit for forecasting the current cool pool forecast surfacing in the eastern and central Pacific, it is forecasting the next subsurface warm pool to be not nothing close as warm as the warm pool earlier in the Spring.

that subsurface warm pool on the forecast looks decent enough for a blend of 2006 or 2009 El Nino this year.not sure if it will be an eastern or Modoki...

[NDG]

All Nino Regions have warmed up during the past week, looks like Nino 3.4 is now up to near 0 deg C.

[Ntxw]

Per the weekly indices, Nino 3.4 is at 0C. Nino 1.2 warmed up to 1.2C, nino 3 to 0.4C, and nino 4 to 0.5C