BoM ENSO Update

[P.K.]

CURRENT STATUS as at 9th August 2006
Next update expected by 30th August 2006 (three weeks after this update).

| Summary | In Brief | Details |

Summary: A persistence of neutral ENSO conditions

The overall ENSO status remains neutral. Generally weak trends have been observed in the main Pacific climate indicators during the past few weeks, and the potential for an El Niño event to develop this year is still relatively low.

At odds with the mainly neutral setting is the Southern Oscillation Index (SOI), which has dipped below −10 during the past week as a result of well above average air pressure at Darwin, and consistently below normal air pressure at Tahiti. This indicates a general weakness in the Pacific Walker Circulation. However, the Trade Winds have increased to somewhat above average strength during the past week after being suppressed for much of July. There was little response to the weakened July Trades in ocean temperatures, and these remain somewhat above average, both on and below the surface. Therefore there is only a slight risk that the Pacific will warm to levels high enough for an El Niño event to develop.

Most of the ENSO prediction models surveyed at the end of July showed a continuation of neutral conditions, although on the warm side of normal. Two of the twelve models suggested the Pacific may warm to El Niño levels by the end of the southern spring. However, a sustained warming beginning in August or September would be unusual, given that ENSO events typically begin to evolve between March and June.

http://www.bom.gov.au/climate/enso/

[AussieMark]

I figured we were still Neutral.

In Brief

* Equatorial Pacific SST values remain a little above average, and have recently increased in the far eastern Pacific and in the central Pacific around the dateline.
* The latest map of weekly subsurface temperatures shows weak warm temperature anomalies above the level of the thermocline across the equatorial Pacific.
* The SOI has a current (7th August) 30-day value of −14.
* The Trade Winds have generally been slightly enhanced in the central to eastern equatorial Pacific during early August, and weaker in the far western equatorial Pacific.
* Cloudiness near the dateline along the equator has been largely suppressed during July. Cloudiness along the equator is currently close to average to the east of the dateline and enhanced to the west.
* Most computer models predict neutral ENSO conditions during the southern spring and summer.

[P.K.]

It is pretty much as expected, and your winter weather would follow it yes. Here is a link to the subsurface temperatures.

[cycloneye]

This will silence some rumors that had been floating around about a el nino making an appeareance during the 2006 hurricane season.

[Jim Hughes]

This will silence some rumors that had been floating around about a el nino making an appeareance during the 2006 hurricane season.

Sorry cycloneye but this doesn't mean anything. This is an opinion that is based heavily on the forecast models, which have never been able to forecast the ENSO well out in advance with any accuracy anyway.

[Jim Hughes]

It is pretty much as expected, and your winter weather would follow it yes. Here is a link to the subsurface temperatures.

The latest updated clip of the CPC's subsurface animiation shows that there is still plenty of warmth as of July 27th. It does not look like the July image that you show. Hard to tell which one is right.

Climatological history tells us that the formation of the El Nino does not occur during summertime but this does not mean that the environment is not becoming conducive for the NOAA criteria. Just consider what happened durig 2002.

We first saw a fairly strong subsurface warming in January 02. It moved eastward and the negative anomalies above reversed and we started to see the early signs of an EL Nino. But it was NOT OFFICAL yet.

We saw another strong subsurface warming some seven months later in August 02'. These warmer waters eventually made it to the surface and this was when we started to see the real SST warming above take hold.

So all of this talk about the surface is somewhat meaningless and it reminds of the talks around here several months back when some people were still trying to tell me that the La Nina was coming back after I had told everyone that it was DEAD.

[P.K.]

The latest updated clip of the CPC's subsurface animiation shows that there is still plenty of warmth as of July 27th. It does not look like the July image that you show. Hard to tell which one is right.

Have you got a link to this animation?

[Jim Hughes]

The latest updated clip of the CPC's subsurface animiation shows that there is still plenty of warmth as of July 27th. It does not look like the July image that you show. Hard to tell which one is right.

Have you got a link to this animation?

Here you go. You can access the t-depth from here. There has been some restructuring going on. The old link does not work.

http://www.cpc.ncep.noaa.gov/products/p ... enso.shtml

[P.K.]

Thanks, I was looking for images like that the other day and couldn't remember where I had seen them.

[Jim Hughes]

Thanks, I was looking for images like that the other day and couldn't remember where I had seen them.

Your welcome. The most recent updated part of the clip, August 1st, shows no subsurface weakening of the warming trend.