El Nino Predicted returning to the South Pacific by Xmas

Environment : 02/08/2008 à 08:00

Strongest El Nino in 10+ years predicted by Christmas

(Tahitipresse) - A U.S. meteorologist and climate researcher has predicted what no one else has so far—a moderate to strong El Nino in the tropical South Pacific Ocean by Christmas that "will likely be the strongest El Nino in over 10 years".

The prediction comes from David Dilley, a former meteorologist with the U.S. National Weather Service who now works for the Global Weather Oscillations Inc. (GWO), which he founded in 1992.

El Nino, one of two great natural Pacific water currents, forms approximately every four to seven years in the tropical South Pacific Ocean. The other Pacific current is known as La Nina, which cooled sea surface waters in the equatorial Pacific from the third quarter of last year through the first quarter of this year.

In April, the Australian Bureau of Meteorology reported that La Nina had begun to weaken, but added that while temperatures were heading back to a neutral range over the next few months, there was no threat of El Nino returning this year.

But by June, La Nina conditions continued to weaken in the equatorial Pacific, a band of ocean running from west to east above and below the equator, according to NIWA, New Zealand's National Institute of Water & Atmospheric Research.

"Overall, the tropical Pacific temperatures are close to neutral, although some remnants of La Nina persist east of the (International) Date Line. A warm water tongue off the coast of Ecuador has strengthened since last month," NIWA reported in its July Island Climate Update.

But NIWA reported on July 30, "The La Nina weather pattern … has now ended. There is no indication of either La Nina or El Nino developing for the rest of the year."

The islands and atolls spread over the five archipelagos of French Polynesia are very concerned any time any meteorological officials start talking about El Nino, which is Spanish for "little boy" and refers to "Christ Child".

An El Nino is a collection of very warm ocean water in the equatorial zone that moves east from near Australia across the tropical South Pacific, all the way to the coast of South America near Ecuador and Peru around Christmas.

And its not only French Polynesia that is concerned by this meteorological phenomenon because its effects can be worldwide, causing disruptions in weather patterns during the winter months in the northern hemisphere and the summer months in the southern hemisphere.

According to U.S. meteorologist and climate researcher Dilley, a recurring gravitational cycle called the "Primary Forcing Mechanism for climate", or PFM, will act like a magnet and cause the South Pacific high pressure center to be pulled out of its normal location in October and November, setting the stage for a moderate to strong El Nino to form in December—the strongest in 10 years.

Dilley says the PFM is "the trigger mechanism that controls recurring cycles of the El Nino, regional hurricane landfalls and other weather/climate cycles".

The PFM has been "correlated with historical climate data to obtain accurate forecast models", he said. "One such research project correlates the PFM with sea surface temperatures in the tropical South Pacific Ocean where the El Nino Southern Oscillations (ENSO) forms.

By doing so, (Dilley's) GWO found a 100% correlation between the 24 PFM cycles to the occurrences of all 24 El Ninos dating back to 1914.

The U.S. Department of Commerce's NOAA (National Oceanic and Atmospheric Administration) reported in a July 28 update prepared by its Climate Prediction Center, "ENSO-neutral conditions are present in the equatorial Pacific Ocean."

But while NOAA found that equatorial sea surface temperatures (SSTs) in the central Pacific Ocean had returned to near-average, "positive SST anomalies continue to increase and expand westward into the east-central Pacific".

Based on its available information, including SST trends and model forecasts, NOAA forecast a continuation of ENSO-neutral conditions into the northern hemisphere fall.

NOAA also reported, "The upper ocean heat content was below-average across the eastern half of the equatorial Pacific Ocean between January 2007 and March 2008." That is the period that La Nina existed. However, the upper ocean heat content "has been above-average and increasing since early April 2008", an indication that an El Nino might be on the way.

According to Dilley and his PFM explanation, the very warm pool of water that built up during the 15 months until March 2008 may be moving east toward South American as an El Nino with easterly trade winds due to shift direction to westerly.

The last time an El Nino's very warm pool of water existed was from April-May-June 1997 through to March-April-May 1998. During that period there were four cyclones or tropical depressions in French Polynesia, according to Météo France, the French meteorological service.

There were 20 cyclones in French Polynesia between 1971 and 2000, with 13 of them occurring during an El Nino period. The worst year was 1983 when there were five cyclones, Météo France reported in its 2004 French Polynesia Climatology Atlas.

Oh no, that's not we need! Sigh, I hope they are wrong, I have my big trip coming December 6th!!

Then again, I found this, the next discussion is tomorrow, so I guess I'll have a look when it gets published:

DIAGNOSTIC DISCUSSION

issued by

CLIMATE PREDICTION CENTER/NCEP

10 July 2008

Synopsis: ENSO-neutral conditions are expected to continue into Northern Hemisphere Fall 2008.

A transition from La Niña to ENSO-neutral conditions occurred during June 2008, as sea surface temperatures (SSTs) returned to near-average across the central and east-central equatorial Pacific Ocean (Fig. 1). Also, positive SST anomalies continued in the eastern equatorial Pacific. Consistent with this pattern, the latest weekly SST index was -0.1oC in the Niño-3.4 region, and +0.4oC in the Niño 1+2 region (Fig. 2). The subsurface oceanic heat content (average temperatures in the upper 300m of the ocean, Fig. 3) and patterns of subsurface temperature anomalies (Fig. 4) also reflected the transition to ENSO-neutral conditions. Positive heat content anomalies were associated with above-average temperatures at thermocline depth across the entire equatorial Pacific, while small negative subsurface temperature anomalies persisted near the Date Line between the surface and 75m depth.

Similar to past transitions, La Niña continues to linger in the atmospheric circulation, but with diminishing strength. Enhanced low-level easterly winds and upper-level westerly winds remain across the central equatorial Pacific, while convection continues to be suppressed in the central equatorial Pacific and slightly enhanced over the far western Pacific. Collectively, these atmospheric and oceanic anomalies are consistent with a return from La Niña to ENSO-neutral.

Most of the recent dynamical and statistical SST forecasts for the Niño 3.4 region indicate ENSO-neutral conditions (-0.5 to 0.5 in the Niño-3.4 region) will continue through Northern Hemisphere Winter 2008-09 (Fig. 5). Despite this model consensus, the possible development of El Niño or La Niña cannot be ruled out due to uncertainty in model forecasts and because ENSO events often form during the second half of the year. Based on current atmospheric and oceanic conditions, recent trends, and model forecasts, ENSO-neutral conditions are expected to continue into Northern Hemisphere Fall 2008.

This discussion is a consolidated effort of the National Atmospheric and Oceanic Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts for the evolution of El Niño/La Niña are updated monthly in the Forecast Forum section of CPC's Climate Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for 7 August 2008. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.

So what does all this mean about the weather for the French Polynesian islands for january 09? The weather prediction is very bad? :eek:

I am sorry, but I don't quite understand all this technological language and the predictions. I understand plain english, that says, weather predictions are for nice sunny warm weather, or weather predictions are for windier, and wetter weather for this time.

TIA! :D :eek:

Basically, the source that Pat posted claims that El Nino conditions are going to start happening around the end of the year. This means an increased risk of storms, basically. The "neutral" conditions mean "normal".

The source that I posted claims not, with a proviso. Their new posting today says this, i.e., there is some small chance of a slide towards El Nino later this year:

Most of the recent dynamical and statistical SST forecasts for the Niño 3.4 region indicate ENSO-neutral conditions (-0.5 to 0.5 in the Niño-3.4 region) will continue into the Northern Hemisphere Spring 2009 (Fig. 5). However, due to the positive heat content anomalies in the Pacific Ocean, the development of El Niño cannot be ruled out during the later part of the year, although chances remain low.

I'm heading there in October. Frankly, even if I was going the end of the year or even next spring I wouldn't worry about it. Last time I was in FP El Nino was in full swing and we had wonderful weather. It's just a luck of the draw as to what your weather is going to be like anywhere. I think in the report they are referring to cyclones being more likely in an El Nino year then they are now. Again, luck of the draw and I wouldn't worry about it.

Pat