2018 ENSO

[AbruptSLR]

As my co-Emperor pointed out, it is past time to start a 2018 ENSO thread, so here goes.

Per the following data issued today by the BoM, the 30-day moving average SOI has plunged down to -3.1:

20171206,20180104,-3.1

[AbruptSLR]

Per the following data issued today by the BoM, the 30-day moving average SOI has dropped down to -3.7:

20171207,20180105,-3.7

[Lord M Vader]

As we apparently have switched the thread to a 2018 analogue, I repost my post from the thread "2017 ENSO". But before that it might be informative to tell you that the ONI number for OND is in at -0,9. This number is lower than during the 2016/2017 La Niña. I also add a pic of the latest sub-surface temperatures showing the warm pool in the WPAC (Courtesy: NOAA).

Well, La Niña should start to weaken considerably in a coupke of weeks or so. The warm pool in the West Pacific is according to Australian BOM a possible precursor to an end of the current event.

From ENSO wrap-up by January 3 at BOM:

"However, a build-up of warmer water beneath the surface of the western Pacific may be a precursor to the end of this event in the coming months."

The rest of 2018 should most likely be a neutral year or maybe with a weak El Niño depending on how quick La Niña weakens and vanish. If 2018 ends up being neutral I'm quite sure we'll see a moderate-strong El Niño emerging in 2019. And yes, that should mean that either 2019 or 2020 will have a good chance to end up being the warmest year on record.

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has dropped down to -4.4:

[AbruptSLR]

As we have started a new year it is probably appropriate to briefly show the first image of three month moving average Ocean Nino Index, ONI, values from 1997 thru OND of 2017.  Per this index an official La Nina event is declared by NOAA after five consecutive three month moving average ONI values have been at, or more negative than, -0.5.  As both SON and OND were below the threshold value of -0.5, for the 2017-18 ENSO season to be officially declared a La Nina event will require that the coming ONI values for NDJ, DJF and JFM all be at, or below, -0.5.  Per the second CFSv2 Nino 3.4 forecast this is likely (but not certain) to occur.

[AbruptSLR]

Per the following NOAA weekly Nino index data; & the first two images issued today by the BoM for the week ending January 7, 2018, showing the Nino 3.4 index and the IOD index, respectively; & the last two images issued today by NOAA showing the Eq Pac, Upper Ocean Heat Anom and the SSTA Evolution, respectively: the ENSO remains in a La Nina condition; but shows signs of weakening over the coming few months:

                     Nino1+2      Nino3         Nino34        Nino4
 Week           SST SSTA    SST SSTA   SST SSTA    SST SSTA
 22NOV2017     20.6-1.2     23.9-1.1     25.9-0.8     28.5-0.1
 29NOV2017     20.8-1.3     23.9-1.1     25.9-0.7     28.5 0.0
 06DEC2017     20.8-1.6     24.1-1.0     25.7-0.8     28.2-0.3
 13DEC2017     21.3-1.3     24.0-1.1     25.8-0.8     28.1-0.3
 20DEC2017     21.6-1.4     23.8-1.4     25.6-1.0     28.1-0.3
 27DEC2017     22.1-1.3     24.4-0.9     26.0-0.6     28.2-0.2
 03JAN2018     22.9-0.8     24.0-1.4     25.8-0.8     28.3-0.1

[AbruptSLR]

The four attached plots issued today by the BoM thru week ending January 7 2018, show the weekly index values for the Nino 1, 2, 3 & 4 regions respectively.  All data shows that we remain in a weak La Nina condition but that this condition is likely to move towards neutral conditions in a few months:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has drifted down to -4.5:

[Sleepy]

This might be better suited elsewhere but I've not been follwing this forum for a while.

Response of Pacific-sector Antarctic ice shelves to the El Niño/Southern Oscillation.
https://www.nature.com/articles/s41561-017-0033-0

Satellite observations over the past two decades have revealed increasing loss of grounded ice in West Antarctica, associated with floating ice shelves that have been thinning. Thinning reduces an ice shelf’s ability to restrain grounded-ice discharge, yet our understanding of the climate processes that drive mass changes is limited. Here, we use ice-shelf height data from four satellite altimeter missions (1994–2017) to show a direct link between ice-shelf height variability in the Antarctic Pacific sector and changes in regional atmospheric circulation driven by the El Niño/Southern Oscillation. This link is strongest from the Dotson to Ross ice shelves and weaker elsewhere. During intense El Niño years, height increase by accumulation exceeds the height decrease by basal melting, but net ice-shelf mass declines as basal ice loss exceeds ice gain by lower-density snow. Our results demonstrate a substantial response of Amundsen Sea ice shelves to global and regional climate variability, with rates of change in height and mass on interannual timescales that can be comparable to the longer-term trend, and with mass changes from surface accumulation offsetting a significant fraction of the changes in basal melting. This implies that ice-shelf height and mass variability will increase as interannual atmospheric variability increases in a warming climate.

Also quoting the last paragraph from the paper.

We have shown how the El Niño/Southern Oscillation affects
the height and mass of ice shelves in the AS sector of the WAIS.
The response in height is the combined effect of two opposing
processes, which are both intensified during El Niño events: sur-
face snow accumulation and ocean-driven basal melting. The
result is an overall height increase, but net mass loss, since the ice
lost from the base has higher density than the fresh snow being
gained at the surface. Ice-shelf response to ENSO variability is
strongest between the Dotson and Ross ice shelves, with a weak
response in Pine Island Bay, the Bellingshausen Sea and west of
the Ross Sea. Given expected increases in total precipitation 49
and frequency of extreme ENSO events 50 as Earth’s atmosphere
warms, our results imply that interannual variability of ice-shelf
height and mass will also increase, stressing the need to quantify
surface accumulation relative to basal melting to project future
changes in Antarctic ice shelves.

Adding a couple of images as well.
Fig1. Relationship between ice-shelf height anomalies and ENSO index.
Fig3. Average oceanic, atmospheric and ice-shelf conditions during two
distinct ENSO phases (El Niño, 1997–1998; and La Niña, 1999–2000).

[Sleepy]

The nino plumes provided by ECMWF hasn't been overly accurate this year.
Here's an animation of Nino3.4 for Jan-Dec. First frame was spot on.

Edit; cropped the animation a bit.

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved down to -5.2:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to -4.8:

[oren]

Nice animation Sleepy.

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has drifted up to -4.5:

[Sleepy]

Nice animation Sleepy.

Thanks oren. They were a lot better in early 2015, adding April 2015 and April 2017.
Also adding the latest from January 2018. FWIW, after forecasts beeing poor for so long, ECMWF plumes are persistently indicating warmer conditions.

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to -3.6:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to -2.8:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to -1.9:

[AbruptSLR]

Per the following NOAA weekly Nino data thru the week centered on Jan 10 2018 and the four attached plots (the first two by NOAA showing the Upper Ocean Heat Anom and the SSTA Evolution, respectively, & the second two by the BoM showing the Nino 3.4 & the IOD, respectively), the ENSO condition remains in a La Nina state:


                     Nino1+2      Nino3         Nino34        Nino4
 Week           SST SSTA    SST SSTA   SST SSTA    SST SSTA

 06DEC2017     20.8-1.6     24.1-1.0     25.7-0.8     28.2-0.3
 13DEC2017     21.3-1.3     24.0-1.1     25.8-0.8     28.1-0.3
 20DEC2017     21.6-1.4     23.8-1.4     25.6-1.0     28.1-0.3
 27DEC2017     22.1-1.3     24.4-0.9     26.0-0.6     28.2-0.2
 03JAN2018     22.9-0.8     24.0-1.4     25.8-0.8     28.3-0.1
 10JAN2018     23.3-0.9     24.3-1.3     25.6-0.9     28.2-0.1

[AbruptSLR]

The four attached plots were issued today by the BoM showing the week Nino indices thru the week ending Jan 14 2018, showing the Nino 1, 2, 3 and 4, respectively.  These plots show that the ENSO remains in a La Nina condition:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has drifted up to -1.6:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to -0.3:

[Lord M Vader]

FINALLY, Jisao came in with the missing two values for November and December! Both November and December were positive (+0,15 and +0,50)  which means that the last four years have been purely positive. However, July, August and October were barely positive at +0,10, +0,09 and +0,05 respectively.

Given the current SSTs it seems likely that January 2018 will continue the string of positive PDO-numbers from JISAO.....

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to +0.5:

[Bruce Steele]

The JISAO PDO index was updated for Nov. at .15 and Dec. at .5   This completes four years with positive numbers.

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to +1.4:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to +2.2:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has drifted up to +2.5:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to +3.3:

[AbruptSLR]

Per the following NOAA weekly Nino data thru the week centered on Jan 17 2018 and the four attached plots (the first two by NOAA showing the Upper Ocean Heat Anom and the SSTA Evolution, respectively, & the second two by the BoM showing the Nino 3.4 & the IOD, respectively), the ENSO condition remains in a La Nina state:

                     Nino1+2      Nino3         Nino34        Nino4
 Week           SST SSTA    SST SSTA   SST SSTA    SST SSTA

 13DEC2017     21.3-1.3     24.0-1.1     25.8-0.8     28.1-0.3
 20DEC2017     21.6-1.4     23.8-1.4     25.6-1.0     28.1-0.3
 27DEC2017     22.1-1.3     24.4-0.9     26.0-0.6     28.2-0.2
 03JAN2018     22.9-0.8     24.0-1.4     25.8-0.8     28.3-0.1
 10JAN2018     23.3-0.9     24.3-1.3     25.6-0.9     28.2-0.1
 17JAN2018     23.9-0.6     24.7-0.9     26.0-0.6     27.9-0.3

[AbruptSLR]

The four attached plots were issued today by the BoM showing the week Nino indices thru the week ending Jan 21 2018, showing the Nino 1, 2, 3 and 4, respectively.  These plots show that the ENSO remains in a La Nina condition:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to +4.1:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has zoomed up to +5.4:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to +6.2:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to +7.0:

[Lord M Vader]

Are we going to see a decent WWB at the beginning of February? The ECMWF forecast is not nearly as bullish as the GFS but is still a decent one. Whether this would be enough to support a major WWB is another question.
In any case, Joint Typhoon Warning Center has two invest areas in the Western Pacific. However, the one north of the equator is not likely to develop given its close proximity to the equator. If it had been further north, it might had been supportive for a setup of twin cyclones. Another thing to enact is that we still are in La Niña mode.

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to +7.8:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved up to +8.6:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has drifted up to +8.9:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has drifted up to +9.2:

[AbruptSLR]

I missed posting this information yesterday, but per the following NOAA weekly Nino data thru the week centered on Jan 24 2018; the first two NOAA images for the Eq Pac showing the Upper Ocean Heat Anom and the SSTA Evolution, respectively; and the last two images issued yesterday by the BoM showing the Nino 3.4 and the IOD, indices, respectively; the ENSO condition remains firmly in the weak La Nina range:

                     Nino1+2      Nino3         Nino34        Nino4
 Week           SST SSTA    SST SSTA   SST SSTA    SST SSTA
 20DEC2017     21.6-1.4     23.8-1.4     25.6-1.0     28.1-0.3
 27DEC2017     22.1-1.3     24.4-0.9     26.0-0.6     28.2-0.2
 03JAN2018     22.9-0.8     24.0-1.4     25.8-0.8     28.3-0.1
 10JAN2018     23.3-0.9     24.3-1.3     25.6-0.9     28.2-0.1
 17JAN2018     23.9-0.6     24.7-0.9     26.0-0.6     27.9-0.3
 24JAN2018     24.0-0.9     24.7-1.1     25.9-0.7     27.8-0.4

[AbruptSLR]

Per the four attached weekly Nino plots thru the week ending Jan 28, 2018, issued yesterday by the BoM, showing the Nino 1, 2, 3 & 4 indices, respectively, the ENSO remains firmly in a weak La Nina condition:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has drifted up to +9.5:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has drifted down to +9.4:

[AbruptSLR]

If the POAMA (issued by the BoM) forecast for the Nino 3.4 index starting January 28 2018 is accurate, we may well be experiencing weak La Nina conditions until around August 2018:

[Lord M Vader]

ASLR, I'm not so sure that the forecast is correct in showing weak La Niña conditions. The warm pool in the Western Pacific is gathering strength and with the upcoming WWB it should be able to finish off the current weak La Niña. I think we'll see cool neutral conditions during this summer.

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved down to +8.9:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved down to +7.9:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has moved down to +6.9:

[AbruptSLR]

Per the attached plot issued today by the BoM, the 30-day moving average SOI has remained constant at +6.9: