ENSO Updates (2007 thru 2023)

[HurricaneBill]

El Nino tends to mean intense cyclones in the SPAC. Hopefully, none will hit the islands recovering from the tsunami. The last thing Samoa and American Samoa need is a repeat of the 2004-2005 season. (Cyclones Meena (4), Nancy (4), Olaf (5), and Percy (5).)

[cycloneye]

Australians update confirms Moderate El Nino

They join Climate Prediction Center in the announcement of El Nino intensifying to Moderate.

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

The Pacific Ocean sea surface remains significantly warmer than the long-term mean over the main El Niño regions. The SST anomaly map for October is available here; the map shows warm anomalies covering most of the tropical Pacific, with anomalies in excess of +1°C evident across much of the central to eastern equatorial Pacific. The central equatorial Pacific has warmed significantly through October, while the western Pacific has cooled. The preliminary monthly NINO indices for October are +0.8°C, +1.0°C and +1.2°C for NINO3, NINO3.4 and NINO4 respectively. When compared with September values, NINO4 has warmed by +0.4°C while NINO3 and NINO3.4 have remained similar in magnitude.

In terms of weekly data, the most recent NINO indices are +1.0°C, +1.2°C and +1.4°C for NINO3, NINO3.4, and NINO4 respectively. When compared with two weeks ago, all NINO indices have warmed; NINO3 and NINO4 have warmed by approximately 0.2°C and NINO3.4 by approximately 0.4°C. Both NINO3.4 and NINO4 now have their highest weekly value for 2009. The 7-day SST anomaly map shows significantly warmer than normal SST extending across most of the tropical Pacific. Anomalies in excess of +1°C are evident along the equator east of 160°E. When compared with anomalies observed two weeks ago, the ocean surface has warmed in the central Pacific and cooled slightly in the far western Pacific and over the Coral Sea. The SST in the Australasian region is now near normal for this time of the year on a weekly scale. Until recently, warm SST anomalies had persisted in this region. Typically these regions are average to cooler than average during an El Niño. An animation of recent SST changes is available.

The sub-surface of the equatorial Pacific Ocean remains warmer than the long-term mean across much of the equatorial Pacific and has recently warmed significantly in central regions. A four-month sequence of Pacific Ocean equatorial temperature anomaly is available here. The sequence shows that the sub-surface water had been slowly cooling since July, however since the start of October the sub-surface has undergone a relatively rapid warming. A recent map for the 5 days ending 26 October shows weak warm anomalies extending across most of the equatorial Pacific, with warm anomalies in excess of +4°C now evident between 160°W and 120°E on a weekly scale. When compared with two weeks ago, the sub-surface has warmed significantly in the central Pacific, related to a recent weakening of the Trade winds. This warming has propagated eastwards during recent weeks. An animation of recent sub-surface changes is available.

An archive of past SST and sub-surface temperature charts is available.

Trade winds have weakened further across most of the tropical Pacific over the past two weeks. The latest weekly wind anomalies are shown in the TAO/TRITON map (small image above) for the five days ending 26 October. The map shows westerly wind anomalies evident on a weekly scale across almost all of the tropical Pacific.

The Southern Oscillation Index (SOI) has been rapidly falling through October with a current 30 day value of the SOI (26 October) of −12; the value for September was +4. The SOI is now at values typical of an El Niño event. (SOI graph, SOI table).

Cloudiness near the date-line over the equatorial Pacific is another important indicator of El Niño conditions, as it typically increases near and to the east of the dateline during these episodes. Somewhat consistent with an El Niño event, cloudiness near the date-line has been generally greater than normal during September and October. Cloudiness over Indonesia and much of northern and eastern Australia has been below average over the last few months, which is also consistent with El Niño conditions. However, there has also been enhanced cloudiness to the west of the date-line, a pattern which is unusual when compared with typical El Niño events, however such conditions have occurred in association with more westerly focused El Niño events, as have occurred in 2006 and to a lesser extent, 2002.

Although recent forecasts from computer models have reduced the peak warming expected in the Pacific Ocean, five of the seven international models surveyed by the Bureau of Meteorology predict that the Pacific SSTs will persist at El Niño levels into 2010. Most models are predicting that Pacific Ocean SSTs will start to cool by March next year, which is the typical timing for the decay of El Niño events. Recent forecasts from the POAMA model, run daily at the Bureau of Meteorology, show a steady warming with SST remaining above El Niño thresholds into early 2010, peaking over the summer months.

[cycloneye]

CFS model and ensembles continue to forecast the demise of El Nino by late spring of 2010.

[boca]

I wish that chart expanded more into the summer but I wouldn't say the demise of El Nino.That chart shows a slight decrease but still well over the 0 mark even into July.

[cycloneye]

Here is a chart that goes to late September.Look at all those lines going down to neutral by the summer months.

http://gmao.gsfc.nasa.gov/cgi-bin/produ ... /index.cgi

[boca]

According to that chart you posted Luis it looks like were headed for a La Nina again by late summer at heart of the season.

[cycloneye]

Climate Prediction Center 11/2/09 Update

The numbers continue to climb in a good way at el Nino 3 and El Nino 3-4 confirming the moderate status of El Nino at this time.

Last week numbers

Niño 4=+1.4ºC
Niño 3.4=+1.1ºC
Niño 3=+0.8ºC
Niño1+2=+ 0.1ºC



This week numbers:
Niño 4=+1.6ºC
Niño 3.4=+1.5ºC
Niño 3=+1.2ºC
Niño1+2=+0.4ºC

http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf

[cycloneye]

Climate Prediction Center November update

Synopsis: El Niño is expected to continue strengthening and last through at least the Northern Hemisphere winter 2009-2010.

During October 2009, sea surface temperature (SST) anomalies increased across the central and eastern equatorial Pacific Ocean (Fig. 1 & Fig. 2). The Niño-3.4 index increased nearly a degree with the most recent weekly value at +1.5oC (Fig. 2). Above-average subsurface temperature anomalies increased across a large region of the central and east-central Pacific, with anomalies ranging between +1 to +5oC by the end of the month (Fig. 3). Consistent with this warming, subsurface oceanic heat content anomalies (average departures in the upper 300m of the ocean, Fig. 4) also increased during the month. In addition, low-level westerly and upper-level easterly wind anomalies strengthened over much of the equatorial Pacific. The pattern of tropical convection also remained consistent with El Niño, with enhanced convection over the west-central Pacific and suppressed convection over Indonesia. Collectively, these oceanic and atmospheric anomalies reflect a strengthening El Niño.

There continues to be disagreement among the models on the eventual strength of El Niño, but the majority indicate that the three-month average Niño-3.4 SST index value will range between +1.0oC and +1.5oC during the Northern Hemisphere winter (Fig. 5). Consistent with the historical evolution of El Niño, a peak in SST anomalies is expected sometime during November-January. At this time, there is a high degree of uncertainty over how long this event will persist. Most of the models suggest that this event will last through March-May 2010, although the most likely outcome is that El Niño will peak at least at moderate strength (3-month Niño-3.4 SST index of +1.0oC or greater) and last through at least the Northern Hemisphere winter 2009-10.

Expected El Niño impacts during November 2009-January 2010 include enhanced precipitation over the central tropical Pacific Ocean and a continuation of drier-than-average conditions over Indonesia. For the contiguous United States, potential impacts include above-average precipitation for Florida, central and eastern Texas, and California, with below-average precipitation for parts of the Pacific Northwest. Above-average temperatures and below-average snowfall is most likely for the Northern Rockies, Northern Plains, and Upper Midwest, while below-average temperatures are expected for the southeastern states.

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

[cycloneye]

Australians 11/11/09 update

This is the warmest el nino since the 2002 event.Amazing how this El Nino has taken off after being weak for a few months.We thought that the weak el nino event would stay until it fades by next spring but here we are with a moderate el nino.

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

Summary: Tropical Pacific Ocean warmest since 2002 El Niño

Central equatorial Pacific Ocean temperatures have continued to warm over the past two weeks, and are now at their highest levels since at least the El Niño event of 2002. Similarly, the 30-day Southern Oscillation Index is lower than at any time since 2005. Leading climate models suggest tropical ocean temperatures will remain above El Niño thresholds into the first quarter of 2010.

A sustained weakening of the Trade Winds during October and early November enabled central Pacific equatorial temperatures to rise up to 2°C above normal. However, average to stronger than average Trade Winds currently over the western Pacific may curtail any further warming during the next fortnight. The distribution of tropical cloud has similarities to the patterns observed in the 2002 and 2006 El Niño events, while recent rainfall patterns over Australia are typical of mature El Niño conditions.

Despite a warming of the oceans to Australia's northwest over the past week, the Indian Ocean Dipole (IOD), as measured by the Dipole Mode Index (DMI), is neutral. The Bureau's POAMA model suggests neutral IOD conditions will persist over the coming months.


Details

Ocean surface temperatures in the central equatorial Pacific have continued to warm and now exceed levels typical of an El Niño event by their greatest margin since the start of the year. The map shows warm anomalies in excess of +1°C covering most of the tropical Pacific east of 160°E, with anomalies exceeding +2°C in parts of the central Pacific. While the central Pacific warmed in October, the far western Pacific west of about 160°E cooled steadily. Until recently, warm SST anomalies had persisted in this region, which was atypical for an El Niño. The map shows near-normal SSTs covering most of the western Pacific and northern waters around Australia. The monthly NINO indices for October were +0.9°C, +1.1°C and +1.3°C for NINO3, NINO3.4 and NINO4 respectively. When compared with September values, NINO4 warmed by approximately +0.5°C and NINO3.4 by approximately +0.2°C. NINO3 remained similar in magnitude.



In terms of weekly data, the most recent NINO indices are +1.4°C, +1.7°C and +1.5°C for NINO3, NINO3.4, and NINO4 respectively. When compared with two weeks ago, all NINO indices have warmed; NINO3 by approximately 0.4°C, NINO3.4 by approximately 0.5°C and NINO4 by approximately 0.1°C. All three NINO indices currently have their highest weekly value for 2009. The 7-day SST anomaly map shows warm anomalies in excess of +1°C covering most of the tropical Pacific east of 160°E, with anomalies exceeding +2°C on a weekly scale across most of the central tropical Pacific. When compared with anomalies observed two weeks ago, the ocean surface has warmed in both the central and eastern Pacific. An animation of recent recent SST changes is available.

The sub-surface of the equatorial Pacific Ocean has also continued to warm in the last two weeks. A large volume of warmer than normal water is now well established beneath the surface of the tropical Pacific. A four-month sequence of Pacific Ocean equatorial temperature anomaly is available here. The sequence shows cooling of the sub-surface from July through September followed by a relatively rapid warming during October. This warming has continued into November. A recent map for the 5 days ending 9 November shows a large volume of sub-surface water more than 3°C warmer than normal for this time of the year extending across much of the central to eastern equatorial Pacific. Warm anomalies in excess of 6°C are now evident between 150°W and 120°W on a weekly scale. When compared with two weeks ago, the sub-surface has warmed strongly in the central Pacific, related to a strong westerly wind burst in the western Pacific during October. This warming has propagated eastwards during recent weeks. An animation of recent sub-surface changes is available.



Trade winds were weaker than the long-term mean across most of the tropical Pacific during October, with a strong westerly wind burst in the western Pacific. The westerly wind burst in the western Pacific was linked to the warming of the surface and sub-surface of the tropical ocean in October and early November as well as to a strong drop in the SOI. A pulse of strengthened Trade Winds has developed over the western Pacific during early November, in association with an approaching Madden-Julian Oscillation (MJO). On a weekly scale weak easterly anomalies are evident in the western equatorial Pacific, while Trade winds are close to the long-term mean in the eastern Pacific. The latest weekly wind anomalies are shown in the TAO/TRITON map (small image above) for the five days ending 9 November.

The SOI has recently stabilised after a rapid fall in October. The latest approximate 30-day SOI value is −15; the monthly value for October was also −15. The SOI is now at values typical of an El Niño event.(SOI table, SOI table).



Cloudiness near the date-line over the equatorial Pacific is another important indicator of El Niño conditions, as it typically increases near and to the east of the dateline during these episodes. Cloudiness near the date-line has generally been slightly below average in recent weeks. However, there has been significant enhanced cloudiness to the west of the date-line, a pattern which is unusual when compared with typical El Niño events, but not unprecedented as such conditions were also observed during the recent 2006 El Niño event and to a lesser extent in the 2002 event. Cloudiness over Indonesia and much of northern and eastern Australia has been below average over the last few months, which is consistent with typical El Niño conditions.

Most international computer models are currently predicting that El Niño conditions will persist throughout the southern hemisphere summer. Five of six international models surveyed by the Bureau of Meteorology forecast SSTs to remain above threshold levels into early 2010. Most models are predicting that Pacific Ocean SSTs will start to cool by March next year, which is the typical timing for the decay of El Niño events. Recent forecasts from the POAMA model, run daily at the Bureau of Meteorology, show a continuation of warming with SST remaining above El Niño thresholds into 2010, peaking over the summer months.

[cycloneye]

The SOI data is mocking the rest of the climatological data. The 30 day average is +1.71, and the 90 day average is +2.45. Perhaps wiser minds than mine can explain what this means for the prospect of El nino this winter and beyond.

Since you made the post in late September,I can tell you that the SOI index tanked to -41 in the daily data and around -15 at the 30 day data in the mid to late October period.That means El Nino increased in strengh to moderate stage as the latest updates from Climate Prediction Center and the Australians haved mentioned.Right now the SOI is not tanking as before but stabilizing.

http://www.longpaddock.qld.gov.au/Seaso ... SOIValues/

[cycloneye]

International Research Institute November update

http://iri.columbia.edu/climate/ENSO/cu ... table.html

ENSO Update
19 November 2009

General Discussion

By mid-November 2009, the NINO3.4 SST anomaly index had risen to values indicative of the moderate El Niño category. Up until recently, the event had maintanined only a weak magnitude, but strong and persistent westerly wind anomalies during September, and especially those during October, substantially increased the SST anomalies in the central and eastern equatorial Pacific. Those wind anomalies also had a substantial impact on the sub-surface ocean, deepening the thermocline. This could allow for further growth and will certainly provide several months of persistence to the current event. The wind anomalies in the western Pacific have become easterly since early November, suggesting that much of the rrecent wind anomalies are due to passage of a very strong MJO, or intraseasonal variability. El Niño conditions are expected to persist through the end of the calendar year and possibly a few additional months.

Out of a large set of dynamical and statistical forecast models, nearly all indicate maintenance of El Niño conditions during the Nov-Dec-Jan season currently in progress. Overall, based on model forecasts and current observations of the ocean surface and subsurface, for the coming Dec-Jan-Feb season the probability for El Niño conditions is estimated at 96%, and for ENSO-neutral conditions approximately 3%. The estimated strength of this El Niño event now appears moderate, and the most likely period of duration is through early 2010.

Technical ENSO Update
19 November 2009

> Current conditions
> Expected conditions

Current Conditions
As of mid-November 2009, SSTs are above-average across much of the equatorial Pacific, indicative of El Niño conditions. Between mid-June and mid-July, SSTs in the east-central tropical Pacific warmed to levels indicative of weak El Niño conditions. Starting in October, strong and persistent westerly wind anomalies in the western Pacific, and extending into the central Pacific, substantially increased the magnitude of the warm SST anomalies. The traditional Southern Oscillation Index (SOI) became very negative during October, as did the equatorial SOI. Intermittent, mostly positive convection anomalies have been observed near and just west of the dateline during the last few months, and such anomalies appeared again, and more strongly, during October. On the oceanic side, equatorial heat content has continued to be above-average since early in the year, and has become larger during October. The SST anomalies may still strengthen further in response to the recent wind anomalies that have deepened the thermocline in the eastern part of the basin.

For October 2009, the SST anomaly in the NINO3.4 region was 0.99 C, barely sufficient to be classified as moderate El Niño conditions for this time of year, For the Aug-Sep-Oct season the anomaly was 0.88 degrees C. Currently the IRI's definition of El Niño conditions rests on an index of SST anomalies, averaged over the NINO3.4 region (5S-5N; 170W-120W), exceeding the warmest 25%-ile of the historical distribution, and similarly for La Niña relative to the 25%-ile coldest conditions in the historical distribution. The NINO3.4 anomaly necessary to qualify as La Niña or El Niño conditions for the Nov-Dec-Jan and the Dec-Jan seasons are approximately (-0.70C, 0.75) and (-0.65, 0.65), respectively.


Expected Conditions

The most recent weekly SST anomaly in the NINO3.4 region is 1.7 C. This is a full degree warmer than last month at this time, and indicates moderate-to-strong El Niño conditions in the tropical Pacific. What is the outlook for the ENSO status going forward? The westerly wind anomalies along the equator in the western Pacific have died down as of November, but those active in October provided substantial deep anomalies to the central and eastern thermocline. The spatial pattern of SST anomalies, and of the subsurface temperature anomalies, has become much more structured and reminiscent of El Niño events. It is still not clear, however, to what extent this pattern of SST anomalies will encourage a strong atmosphere response that would lead to air-sea couping of the type observed in strong El Niño events. It is possible that well timed, but independent, intra-seasonal variability in the atmosphere could provide such a kick to the ocean. However, incorporation of such variability is largely beyond the capability of current ENSO prediction models.

November is a time of year when existing ENSO events are near their mature phase, and typically persist for several subsequent months. Therefore, it seems most likely that El Niño conditions will persist through the end of the year, and given the current subsurface anomalies, it may strengthen further.

Presently, the models and observations taken together indicate probabilities of about 96% for maintaining El Niño conditions and about 3% for dissipation to ENSO-neutral conditions for the Nov-Dec-Jan season in progress. Going forward, probabilities for El Niño stay above 90% until Feb-Mar-Apr, after which they decrease to approximately 55% by Apr-May-Jun 2010, falling to climatological probabilities of 25% by Jul-Aug-Sep. Probabilities for La Niña conditions are predicted to be negligible for the next several months, not exceeding 10% until Apr-May-Jun 2010.

The above assessment was made in part on the basis of an examination of the current forecasts of ENSO prediction models as well as the observed conditions. For purposes of this discussion, El Niño SST conditions are defined as SSTs in the NINO3.4 region being in the warmest 25% of their climatological distribution for the 3-month period in question over the 1950-present timeframe. The corresponding cutoff in terms of degrees C of SST anomaly varies seasonally, being close to 0.40 degrees C in boreal late-spring to early-summer season and as high as 0.75 degrees C in late boreal autumn. La Niña conditions are defined as NINO3.4 region SSTs being in the coolest 25% of the climatological distribution. Neutral conditions occupy the remaining 50% of the distribution. These definitions were developed such that the most commonly accepted El Niño and La Niña episodes are reproduced.

The models are somewhat varied in their ENSO forecasts through the 10-month forecast period. The statistical and dynamical models are in agreement in predicting El Niño conditions through the end of this year. The warmest NINO3.4 forecasts come from the dynamical models. For the current Nov-Dec-Jan season, most (95%) are predicting El Niño conditions, and 5% predict ENSO-neutral conditions. At lead times of 4 or more months into the future, statistical and dynamical models that incorporate information about the ocean's observed sub-surface thermal structure generally exhibit higher predictive skill than those that do not. Among models that do use sub-surface temperature information, 14 of 15 (93%) indicate El Niño conditions for the Mar-Apr-May season, and 1 of 15 (7%) predict ENSO-neutral SSTs. (Note 1). Caution is advised in interpreting the distribution of model forecasts as the actual probabilities. At longer leads, the skill of the models degrades, and skill uncertainty must be convolved with the uncertainties from initial conditions and differing model physics, leading to more climatological probabilities in the long-lead ENSO Outlook than might be suggested by the suite of models. Furthermore, the expected skill of one model versus another has not been established using uniform validation procedures, which may cause a difference in the true probability distribution from that taken verbatim from the raw model predictions.

[cycloneye]

At least the 30 day SOI index is not tamking as it has gone up in the past week a little bit meaning that the growth of El Nino has stopped and mantains at Moderate.

[cycloneye]

Australians 11/25/09 update

Not a lot of changes compared to their last update.

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

Details
The Pacific Ocean sea surface temperature (SST) remains significantly warmer than the long-term mean over the key El Niño regions. The SST anomaly map for October to is available here; the map shows warm anomalies in excess of +1°C covering most of the tropical Pacific east of 160°E, with anomalies exceeding +2°C in parts of the central Pacific. The map also shows near-normal SSTs covering most of the western Pacific and northern waters around Australia. The preliminary monthly NINO indices for November are +1.3°C, +1.6°C and +1.5°C for NINO3, NINO3.4 and NINO4 respectively. When compared with October values each NINO region has warmed; NINO3 by approximately 0.4°C, NINO3.4 by 0.5°C and NINO4 by 0.2°C.

In terms of weekly data, the most recent NINO indices are +1.3°C, +1.6°C and +1.6°C for NINO3, NINO3.4, and NINO4 respectively. When compared with two weeks ago there has been little change in value of the NINO indices. while NINO4 has warmed slightly (also by approximately 0.1°C). The 7-day SST anomaly map shows warm anomalies in excess of +1°C covering most of the tropical Pacific east of 160°E, with anomalies exceeding +2°C on a weekly scale across most of the central tropical Pacific. When compared with anomalies observed two weeks ago, the ocean surface has cooled very slightly across the central and eastern Pacific,

The sub-surface of the equatorial Pacific Ocean has also cooled very slightly in the last two weeks. However, the sub-surface still remains significantly warmer than the long-term mean and shows a clear El Niño pattern. A four-month sequence of Pacific Ocean equatorial temperature anomaly is available here. The sequence shows cooling of the sub-surface through August and September followed by a relatively rapid warming through October and early November. A recent map for the 5 days ending 23 November shows a large volume of sub-surface water more than 2°C warmer than normal for this time of the year extending across much of the central to eastern equatorial Pacific. Warm anomalies in excess of 5°C are evident between 140°W and 110°W on a weekly scale. When compared with two weeks ago, the sub-surface has cooled slightly. This is related to the return to normal Trade wind conditions.

Trade winds have strengthened across the tropical Pacific during November, and are now near normal. Trade winds were weaker than the long-term mean across most of the tropical Pacific during October, with a strong westerly wind burst observed in the western Pacific. The westerly wind burst was linked to the warming of the surface and sub-surface of the tropical Pacific in October and early November, as well as a strong drop in the SOI. The latest weekly wind anomalies are shown in the TAO/TRITON map (small image above) for the five days ending 24 November.

The SOI has recently increased after a rapid fall in October. The latest (24 November) approximate 30-day SOI value is −10; the monthly value for October was also −15. The SOI is remains at values typical of an El Niño event

Cloudiness near the date-line over the equatorial Pacific is another important indicator of El Niño conditions, as it typically increases near and to the east of the dateline during these episodes. Cloudiness near the date-line has increased in the last week, while cloudiness over Indonesia and much of northern and eastern Australia has remained below average; typical cloud patterns for an El Niño.

Most international computer models are currently predicting that El Niño conditions will persist throughout the southern hemisphere summer. Five of six international models surveyed by the Bureau of Meteorology forecast SSTs to remain above threshold levels into early 2010. A number of computer models are predicting that Pacific Ocean SSTs will start to cool by March next year, which is the typical timing for the decay of El Niño events. Recent forecasts from the POAMA model, run daily at the Bureau of Meteorology, show a continuation of warming with SSTs remaining above El Niño thresholds into 2010, peaking over the summer months.

[cycloneye]

Climate Prediction Center weekly update

El Nino continues to be in a Moderate status.

The latest weekly SST departures are:
Niño 4= +1.6ºC
Niño 3.4= +1.7ºC
Niño 3= +1.3ºC
Niño1+2= +0.2ºC

http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf

[CrazyC83]

Is there a chance this could turn into a repeat of El Ninos like 1982-83 and 1997-98?

[cycloneye]

Is there a chance this could turn into a repeat of El Ninos like 1982-83 and 1997-98?

I think the critical time to know if El Nino will stay moderate or starts to fade will be in March.

[jinftl]

Dr. Jeff Master's season wrap-up featured this interesting tidbit of info:

Since 1950, there have been 17 El Niño events, and only one of them lasted through two full hurricane seasons. Thus, we can expect neutral or La Niña conditions for next year's hurricane season, which should lead to much higher levels of activity than in 2009.
http://www.wunderground.com/blog/JeffMa ... rynum=1390


Also, there weren't technically 2 back-to-back seasons with el nino's during the 82/83 and 97/98 seasons...the last official oni index that showed a 3-month average of el nino conditions in 1983 was May-June-July...the rest of the season was enso neutral until Sept-Oct-Nov., when borderline la nina conditions were met. Similarly, the last el nino reading in 1998 was the April-May-June composite average. La nina conditions were present by July-Aug-Sept of '98.
http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf
(see pg. 25)

[cycloneye]

Its early but these are the most important and reliable ENSO models,CFS and POAMA models and both show the trend towards neutral ENSO starting by late spring or early summer.Lets continue to follow the data to see if the proyections are good about El Nino fading by late spring 2010.

Australian model POAMA



NCEP model CFS

[Derek Ortt]

the ensembles are forecasting a solid el nino next season

if this verifies, we may be quite quiet

[cycloneye]

Climate Prediction Center 12/7/09 weekly update

The most important area of ENSO El Nino 3-4 area stayed the same between last week update and this week so it continues to be in a moderate status.

Last week numbers

Niño 4= +1.6ºC
Niño 3.4= +1.7ºC
Niño 3= +1.3ºC
Niño1+2= +0.2ºC

http://www.cpc.ncep.noaa.gov/products/a ... ts-web.pdf


This week numbers:

Niño 4= +1.4ºC
Niño 3.4= +1.7ºC
Niño 3= +1.4ºC
Niño1+2= +0.4ºC