ENSO Updates (2007 thru 2023)

[StruThiO]

From today's MJO update: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjoupdate.pdf

[Kingarabian]

From today's MJO update: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjoupdate.pdf

https://i.imgur.com/C93IK6x.png

Interesting that the CPC is mentioning it that bluntly. I think it has to be considered with ONI possibly coming dangerously close to meeting the 5 tri-monthly requirement by May, and we keep seeing WWB after WWB.

Euro, GFS and CFS hovmollers show a strong -VP concentration over the dateline with the MJO moving through by February 17.

[cycloneye]

Wide range of outcomes for next Summer.

 https://twitter.com/AndyHazelton/status/1227221894983585792

[aspen]

Wide range of outcomes for next Summer.

https://twitter.com/AndyHazelton/status/1227221894983585792

It seems like most outcomes are favoring a warmer-than-normal subtropics, so maybe we could see more activity there like in the 2018 season.

[Kingarabian]

GFS has the upcoming WWB stronger:

[cycloneye]

 https://twitter.com/EricBlake12/status/1227736846819569674

[Kingarabian]

Euro February Nino 3.4 forecast is out. Continues its shift since November to an overall warmer ENSO state for the summer.

[cycloneye]

EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
13 February 2020

ENSO Alert System Status: Not Active


Synopsis: ENSO-neutral is favored through Northern Hemisphere spring 2020 (~60% chance), continuing through summer 2020 (~50% chance).

During January 2020, near- to above-average sea surface temperatures (SSTs) were evident across most of the equatorial Pacific Ocean [Fig. 1]. The latest weekly Niño-3.4 and Niño-3 indices were near average (+0.2°C to 0.0°C), while the Niño-4 and Niño-1+2 indices were warmer at +1.2°C and +0.8°C, respectively [Fig. 2]. After decreasing in early to mid January, positive equatorial subsurface temperature anomalies (averaged across 180°-100°W) slightly increased during the latter part of the month [Fig. 3]. Temperatures remained above average across most of the subsurface ocean, reaching ~150m depth in the central Pacific [Fig. 4]. During the month, westerly wind anomalies persisted over the western equatorial Pacific Ocean, while upper-level winds were mostly westerly over the east-central and eastern equatorial Pacific. Tropical convection remained suppressed over Indonesia and was enhanced around the Date Line [Fig. 5]. The traditional and equatorial Southern Oscillation indices were near zero. Overall, the combined oceanic and atmospheric system remained consistent with ENSO-neutral.

The majority of models in the IRI/CPC plume [Fig. 6] continue to mostly favor ENSO-neutral (Niño-3.4 index between -0.5°C and +0.5°C) through the Northern Hemisphere summer. The forecaster consensus predicts the Niño-3.4 index will be at or slightly above +0.5°C for the January - March 2020 season, but then slightly favors ENSO-neutral for the February - April 2020 season. While it is expected that oceanic temperatures will remain elevated in the near term, particularly in the western and central equatorial Pacific Ocean, most models predict a gradual decrease in Niño-3.4 SST anomalies into the spring and summer. In summary, ENSO-neutral is favored through Northern Hemisphere spring 2020 (~60% chance), continuing through summer 2020 (~50% chance; click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).

https://www.cpc.ncep.noaa.gov/products/ ... odisc.html

[Kingarabian]

EL NIÑO/SOUTHERN OSCILLATION (ENSO)
DIAGNOSTIC DISCUSSION
issued by
CLIMATE PREDICTION CENTER/NCEP/NWS
and the International Research Institute for Climate and Society
13 February 2020

ENSO Alert System Status: Not Active


Synopsis: ENSO-neutral is favored through Northern Hemisphere spring 2020 (~60% chance), continuing through summer 2020 (~50% chance).

During January 2020, near- to above-average sea surface temperatures (SSTs) were evident across most of the equatorial Pacific Ocean [Fig. 1]. The latest weekly Niño-3.4 and Niño-3 indices were near average (+0.2°C to 0.0°C), while the Niño-4 and Niño-1+2 indices were warmer at +1.2°C and +0.8°C, respectively [Fig. 2]. After decreasing in early to mid January, positive equatorial subsurface temperature anomalies (averaged across 180°-100°W) slightly increased during the latter part of the month [Fig. 3]. Temperatures remained above average across most of the subsurface ocean, reaching ~150m depth in the central Pacific [Fig. 4]. During the month, westerly wind anomalies persisted over the western equatorial Pacific Ocean, while upper-level winds were mostly westerly over the east-central and eastern equatorial Pacific. Tropical convection remained suppressed over Indonesia and was enhanced around the Date Line [Fig. 5]. The traditional and equatorial Southern Oscillation indices were near zero. Overall, the combined oceanic and atmospheric system remained consistent with ENSO-neutral.

The majority of models in the IRI/CPC plume [Fig. 6] continue to mostly favor ENSO-neutral (Niño-3.4 index between -0.5°C and +0.5°C) through the Northern Hemisphere summer. The forecaster consensus predicts the Niño-3.4 index will be at or slightly above +0.5°C for the January - March 2020 season, but then slightly favors ENSO-neutral for the February - April 2020 season. While it is expected that oceanic temperatures will remain elevated in the near term, particularly in the western and central equatorial Pacific Ocean, most models predict a gradual decrease in Niño-3.4 SST anomalies into the spring and summer. In summary, ENSO-neutral is favored through Northern Hemisphere spring 2020 (~60% chance), continuing through summer 2020 (~50% chance; click CPC/IRI consensus forecast for the chance of each outcome for each 3-month period).

https://i.imgur.com/NeqRfbH.png

https://www.cpc.ncep.noaa.gov/products/ ... odisc.html

This was the case for the past two years. Crucial to see what happens in mid March and early April. Years like 2014, 2018, and 2019 westerly wind activity was scarce by mid and late Spring.

Regardless and as Paul Roundy has pointed out, it's entirely possible to see an El Nino event initiate through winter and early spring, only to peak and dissipate come summertime.

[Kingarabian]

 https://twitter.com/MJVentrice/status/1227918060868296704

[Kingarabian]

Compared to MJO activity in the fall and late December: the suppressed phase of the MJO in January did not make it past the dateline, and the CFS and Euro show the upcoming suppressed phase of the MJO for February also not making it past the dateline. Although it's weak, there is some rising air branch typically associated with warm-Enso/El Nino situated over the dateline. At the same time, strong sinking air continues to dominate over Australia and the MC.

[WeatherEmperor]

Here are the numbers for today's update:

Nino 1+2: +0.1C (down from +0.8)
Nino 3: +0.3C (up from 0.0)
Nino 3.4: +0.1C (down from +0.2)
Nino 4: +0.9C (down from +1.2)

Source: https://www.cpc.ncep.noaa.gov/data/indi ... st8110.for

[Kingarabian]

Lack of a warm PDO signature is probably aiding high pressure off of the WCONUS, leading to enhanced trades down to the equator of the EPAC, thus probably hurting the EPAC from warming more rapidly. TAO buoys continue to show the strongest warm anomalies of this downwelling Kelvin wave remaining west of 140W. We also need to see how much this recent WWB affected the subsurface.

16 day EPS shows steady rising air over the dateline:


Beginning on the first week of March, the 46 day EPS and 1month CFS show a prolonged MJO event beginning over the"El Nino phases". So we'll probably see a strong WWB by mid March.

PC - Weathermodels.com

[cycloneye]

 https://twitter.com/philklotzbach/status/1230181243112714240

[SFLcane]

Another busy season likely awaits in 2020.

https://twitter.com/philklotzbach/status/1230181243112714240

[Kingarabian]

Another busy season likely awaits in 2020.

https://twitter.com/philklotzbach/status/1230181243112714240

From this graph, four models in the NASA, CFS, LDEO, and COLA CCSM are weighing the average heavily towards La Nina. I'm not sure how good the NASA, LDEO, and COLA CCSM models are and if they get their information from NCEP... But the CFS's Nino 3.4 forecast is completely contradicting its own VP200 and 850mb wind forecasts.

In a couple of days, models have a hurricane strength TC impacting Darwin and its surrounding areas for the rest of the week. Strong potential that the SOI numbers will be skewered as a result.

[Kingarabian]

After being stagnant for nearly a month, there's been a notable expansion and warming in the anomalies of the present downwelling Kelvin wave within the past week. +2C anomalies have moved past 140W.

[Kingarabian]

This weeks numbers:
Niño 4: 1.1ºC
Niño 3.4: 0.6ºC
Niño 3: 0.2ºC
Niño 1+2: 0.3ºC

[Kingarabian]

Due to the mid-February WWB, we should see warm anomalies build back up beneath the CPAC in the upcoming weeks. But there's some doubt if these warm anomalies can reach the EPAC, especially if the 850mb wind forecasts from the CFS and GFS verify.

If you want a La Nina for summer 2020, the CFS shows you how to do it:


GFS also showing a strong trade burst over the EPAC:


There are some differences in how the models are handling the MJO so this strong trade burst could be limited to the NCEP based models. Euro shows a much weaker trade burst compared to the GFS due to it having the MJO emerging out of the MC and into the Pacific stronger.

[Kingarabian]

It's also important to note that while models are making the trades stronger over the EPAC, all the models continue to keep wind activity over the dateline anomalously westerly. This has been the case all winter long regardless of the MJO being present or not. For a La Nina or cool-neutral to develop, there needs to be trade winds over the dateline to stop the transfer of warm waters from the WPAC to the CPAC/EPAC.

Also, if there's to be a La Nina or a cool-neutral season, there typically needs to be stronger MJO pulses over the Indian ocean. Based on RMM, since December, the MJO has mainly been stronger in phases 5/6/7 - and for March this could continue with the Euro and CMC showing it back over the MC and WPAC. I understand there is a strong IO standing wave and its hard for the MJO to reflect on the RMM charts, but nearly all La Nina and cool-neutral seasons had RMM charts show an MJO pulse over the Indian ocean sometime during February or March. So this is something to pay attention to.



View RMM historical charts here:
http://www.bom.gov.au/climate/mjo/