ENSO Updates (2007 thru 2023)

[cycloneye]

The Australian POAMA model decends to neutral by June.

http://www.bom.gov.au/climate/coupled_model/poama.shtml

[CrazyC83]

This sure makes predicting the 2010 hurricane season a nightmare.

[KWT]

I wouldn't be all that surprised if the El nino doesn't weaken quite as fast as some models prog and I'm certainly not seeing any reason to call la nina despite some of the ensembles suggesting its a risk.

[Hurricaneman]

I just looked at the subsurface and there seems to be a kelvin wave between 130w and 160w

[cycloneye]

I just looked at the subsurface and there seems to be a kelvin wave between 130w and 160w

This KW may be the last straw of El Nino as the models have a mini spike at this time and then go down to Neutral.

[KWT]

Yeah, may well also make the El Nino east based as well for a time which may make for a slower start to the season before it fades away.

[cycloneye]

The CFS model forecasts ENSO to go Neutral by June,but stays that way and not enters La Nina freshold.For those members who may not know when it is Neutral,is between +0.5 to -0.5.

[KWT]

Yeah I like the CFS forecast and I think it won't be far short, I also like the way they see a slight rise again this month which makes sense giving the way we are seeing warming at the subsurface level so I'm expecting a slight rise, maybe upto 1.3-1.4C on the weeklies before a drop towards the bottom end of El Nino for May-June, after that slight weakening should continue into the summer to take it IMO just shy of El Nino, at warm Neutral.

Either way odds favour the 3.4 zone being weaker then it was last summer even if El nino hangs on later then expected.

[cycloneye]

I found these interesting graphics about how many landfalls occur in the three different ENSO phases El Nino (Warm),Neutral and La Nina (Cold) on the east coast of the U.S. and in Florida.

East Coast Landfalls



Florida Landfalls

[ROCK]

I found these interesting graphics about how many landfalls occur in the three different ENSO phases El Nino (Warm),Neutral and La Nina (Cold) on the east coast of the U.S. and in Florida.

East Coast Landfalls



Florida Landfalls

what about Texas?? you are beginning to sound like JB...

[cycloneye]

Australian 3/3/10 update

As expected,a small stall in the decline of El Nino as the models predicted is occuring at this time.Once this period ends,it will be adios to El Nino and hello to Neutral ENSO by late Spring or early Summer.

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

Details

The Pacific Ocean sea surface temperature (SST) remains warmer than the long-term average across the central and eastern tropical Pacific. The SST anomaly map for February shows warm anomalies in excess of +1°C covering most of the central equatorial Pacific and parts of teh eastern tropical Pacific. The monthly NINO indices for February were +0.9°C, +1.2°C and +1.0°C for NINO3, NINO3.4 and NINO4 respectively. When compared with January values, both NINO3 and NINO4 have cooled by 0.2°C and NINO3.4 by 0.3°C.

In terms of weekly data, the most recent NINO indices are +0.9°C, +1.2°C and +1.0°C for NINO3, NINO3.4 and NINO4 respectively. When compared with two weeks ago, both NINO3 and NINO4 have warmed slightly by approximately 0.1°C, while NINO3.4 has remained the same in magnitude. The 7-day SST anomaly map shows warm anomalies covering most of the tropical Pacific east of 170³E. When compared with anomalies observed a fortnight ago, there has been little change in the distribution of heat at the sea surface along the equator. An animation of recent SST changes is available.

A four-month sequence of sub-surface Pacific Ocean equatorial temperature anomaly shows a cooling of the sub-surface since the peak in warmth during November. During December and January, weak cool anomalies in the western Pacific propagated eastwards, cooling the sub-surface of the central and eastern Pacific. The western and eastern Pacific continued to cool through February; however the central Pacific has shown some renewed warming. A recent map for the 5 days ending 28 February shows that a large volume of warmer than normal water persists below the surface of the central to eastern tropical Pacific, with anomalies exceeding +4°C in small regions. When compared with two weeks ago, the sub-surface of the equatorial Pacific has cooled slightly in western and central regions and warmed slightly in the eastern Pacific. This recent warming is likely to be a response to a weakening of the trade winds over the western and central Pacific during late January and early February. An animation of recent sub-surface changes is available.



Trade winds have strengthened in the central and eastern Pacific during the last fortnight and are now close to average strength over most of the tropical Pacific. However, some westerly wind anomalies are still evident in the central and western Pacific to the south of the equator. The latest weekly wind anomalies are shown in the TAO/TRITON map.



The SOI has increased in value over the last week after a rapid fall during February. This fall in value was attributed to a sharp decline in mean sea level pressure over Tahiti; in part due to several tropical depressions and Severe Tropical Cyclone Oli passing over the region. During this time the SOI reached a 30-day value of −24 on the 12th of February; the lowest value of the SOI recorded during this El Niño event. The current (1 March) 30-day value of the SOI is −16, while the monthly value for February was −14. (SOI graph, SOI table).





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

Cloudiness near the date-line across 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 decreased over the past fortnight, but still remains above average. Cloudiness near the date-line was particularly enhanced during late January and early February, coinciding with a weakening of the trade flow in the region and a big drop in the SOI.

Most international computer models are predicting a return to neutral conditions by late autumn in the southern hemisphere. Typically, autumn is a transitional period for the El Niño - Southern Oscillation (ENSO), hence model predictions of El Niño that forecast through this period tend to be less reliable than at other times of the year. Recent forecasts from the POAMA model, run daily at the Bureau of Meteorology, show a steady cooling of the central Pacific with SSTs returning to neutral conditions during the southern hemisphere autumn.

[KWT]

I think we are going to see a rise in the next few weeks maybe back upto moderate status briefly, those subsurface temps are looking mighty impressive again all of the sudden thanks to the KW...after that and we should see a decline, I think the CFS has a good grip on the eventual outcome now IMO.

Also looks like its going to become east based if that does upwell enough but we shall see

[cycloneye]

Another graphic that shows how are things going in the Pacific in terms of ENSO.It updates daily.

[cycloneye]

Climate Prediction Center March update

El Nino will continue until at least late Spring or early Summer.

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

Synopsis: El Niño is expected to continue at least through the Northern Hemisphere spring 2010.

A moderate-to-strong El Niño continued during February 2010, with sea surface temperature (SST) anomalies exceeding 1.5oC in parts of the equatorial Pacific Ocean at the end of the month (Fig. 1). Weekly values of the Niño-3.4 index remained steady at +1.2oC during February (Fig. 2). An oceanic Kelvin wave was initiated in early February, which acted to increase the subsurface heat content anomalies (average temperatures in the upper 300m of the ocean, Fig. 3), and to strengthen subsurface temperature departures (exceeding +2oC down to 100-175m) across much of the equatorial Pacific (Fig. 4). SSTs were sufficiently warm to support deep tropical convection, which strongly increased across the central and eastern tropical Pacific, while remaining suppressed over Indonesia (Fig. 5). Equatorial low-level westerly wind anomalies also strengthened during February, while upper-level easterly wind anomalies weakened slightly. Collectively, these oceanic and atmospheric anomalies reflect a moderate-to-strong El Niño episode.

Nearly all models predict decreasing SST anomalies in the Niño-3.4 region through 2010, with the model spread increasing at longer lead times (Fig. 6). The majority of models predict the 3-month Niño-3.4 SST anomaly will drop below +0.5oC by May-June-July 2010, indicating a transition to ENSO-neutral conditions near the onset of Northern Hemisphere summer. However, several models suggest the potential of continued weak El Niño conditions through 2010, while others predict the development of La Niña conditions later in the year. Predicting when El Niño will dissipate and what may follow remains highly uncertain.

El Niño impacts are expected to last through the Northern Hemisphere spring, even as equatorial SST departures decrease, partly in response to the typical warming that occurs between now and April/May. Expected impacts during March-May 2010 include drier-than-average conditions over Indonesia and enhanced convection over the central and eastern equatorial Pacific Ocean, as well as coastal sections of Peru and Ecuador. For the contiguous United States, potential El Niño impacts include above-average precipitation for the Southwest, the south-central states, and Florida, and below-average precipitation in the Pacific Northwest and Great Lakes region. Above-average temperatures are most likely across the northern tier of states (excluding New England and the Northern Plains), while below-average temperatures are favored for the south-central and southeastern states.

[cycloneye]

These are the graphics of the montly forecasts by CFS model.Notice that El Nino appears to be gone by July.

[cycloneye]

Climate Prediction Center 3/8/10 weekly update

There have been a decrease in all the El Nino areas but not by a lot as you can see below.

Last Week Numbers

Niño 4= +1.2ºC
Niño 3.4= +1.2ºC
Niño 3= +0.9ºC
Niño1+2= +0.4ºC


This Week Numbers

Niño 4= +1.1ºC
Niño 3.4= +1.1ºC
Niño 3= +0.7ºC
Niño1+2= +0.1ºC


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

[KWT]

Its more or less holding firm, which is in itself quite interesting given the subsurface temps we had in the last 2-3 weeks, once this eases off I wouldn't at all be surprised to see it drop to borderline El Nino just like the CFS suggests by June/July.

[Derek Ortt]

June/July el nino may still mean a significantly reduced Atlantic cane season

enough ensemble members are hanging onto an el nino to cause me to largely discount the predictions of a hyperactive season. Season may actually end up similar to last year's

[KWT]

Possibly but every other factor screams very active so I wouldn't have thought a borderline ENSO event is really going to do much at all, it certainly hasn't in years like 69 and 2004 which also saw many other factors be favourable for development.

That being said the uncertainty with the El Nino also precludes me to call for hyperactive just yet...but I really can't see a season like last year at all to be honest Derek, too many other factors are the polar opposite to what they were last year, if anything 2007 maybe a closer call with a decent number of storms but alot being sheared systems, but any systems that do get good conditions have the chance to explode...but anything is possible.

[Derek Ortt]

2004 also was a building el nino. This year's ENSO seems more similar to 1992-1993 ish where a weak el nino lingered into the start of the next season. The result was strong shear throughout the entire season

the strong shear should balance out the lower SLP for the Caribbean. May have a few sheared TCs forming there, however