Theoretically El Nino Not Possible During 2017 – ENSO Neutral Conditions Prevails With MJJ 2017 ONI Index At +0.3ºC

ENSO Status on 4th August 2017

 

The ONI is based on SST departures from average in the Niño 3.4 region, and is a principal measure for monitoring, assessing, and predicting ENSO. Defined as the three-month running-mean SST departures in the Niño 3.4 region. Departures are based on a set of improved homogeneous historical SST analyses (Extended Reconstructed SST – ERSST.v4). The SST reconstruction methodology is described in Huang et al., 2015, J. Climate, vol. 28, 911-930.
CPC uses current Climatology based on 1986-2015 which has been changed late last year from base years 1981-2010. Explanation about Climatology base years change is given here.

NOAA Operational Definitions for El Niño and La Niña, El Niño: characterized by a positive ONI greater than or equal to +0.5ºC. La Niña: characterized by a negative ONI less than or equal to -0.5ºC. By historical standards, to be classified as a full-fledged El Niño or La Niña episode, these thresholds must be exceeded for a period of at least 5 consecutive overlapping 3-month seasons.

CPC considers El Niño or La Niña conditions to occur when the monthly Niño3.4 OISST departures meet or exceed +/- 0.5ºC along with consistent atmospheric features. These anomalies must also be forecast to persist for 3 consecutive months.

Short lived La Nina ended with last 3-monthly season as NDJ 2017. Subsequently, Enso neutral conditions have prevailed thereafter.

ONI Index for DJF 2017 was -0.4ºC, JFM 2017 was -0.2ºC, FMA 2017 was +0.1ºC, MAM was +0.4ºC, AMJ was +0.4ºC and now the last ONI Index MJJ is +0.3ºC, hence the Nino 3.4 Region of Pacific Ocean continues to remain in ENSO Neutral zone.

 

Latest Oceanic Nino Index (ONI) Graph Showing Enso Neutral Event For Last Three 3- Monthly Seasons Ending July 2017

 

 

 

The Table below shows the monthly SST of Nino3.4 Region and the Climate adjusted normal SST and SST anomaly for last two years. Climate Base 1986-2015.

Period    Nino3.4 ClimAdjust
YR   MON  Temp.ºC Temp.ºC ANOM ºC

2015   7   28.50   27.37    1.13
2015   8   28.47   27.02    1.45
2015   9   28.62   26.94    1.68
2015  10   28.86   26.91    1.95
2015  11   29.14   26.88    2.25
2015  12   29.04   26.80    2.24
2016   1   28.95   26.61    2.33
2016   2   28.89   26.80    2.09
2016   3   28.86   27.32    1.54
2016   4   28.96   27.86    1.10
2016   5   28.59   27.98    0.60
2016   6   27.81   27.76    0.05
2016   7   26.98   27.37   -0.39
2016   8   26.39   27.02   -0.63
2016   9   26.20   26.94   -0.74
2016  10   26.04   26.91   -0.87
2016  11   25.96   26.88   -0.93
2016  12   26.08   26.80   -0.72
2017   1   26.24   26.61   -0.37
2017   2   26.63   26.80   -0.17
2017   3   27.49   27.32    0.17
2017   4   28.30   27.86    0.44
2017   5   28.54   27.98    0.56
2017   6   27.97   27.76    0.21
2017   7   27.40   27.37    0.03

 

CPC considers El Niño or La Niña conditions to occur when the monthly Niño3.4 OISST departures meet or exceed +/- 0.5°C along with consistent atmospheric features. These anomalies must also be forecast to persist for 3 consecutive months.

 

Southern Oscillation Index

 

As per BOM, Australia:

The 30-day Southern Oscillation Index (SOI) on 30 July was +8.1 (90-day value −0.4). SOI values have generally been within the neutral range since mid-October. However, recently they have shot up and flirting the positive zone.

The latest 30-day Southern Oscillation Index (SOI) on 31st July 2017 is +8.7 which is flirting the positive zone.

 

 

Sustained positive values of the SOI above +7 typically indicate La Niña while sustained negative values below −7 typically indicate El Niño. Values between about +7 and −7 generally indicate neutral conditions.

 

SOI Monthly graph up to July 2017 as per The Long Paddock – Queensland Government.

 

 

30 Days average SOI was +6.51 at the end of July 2017 and +8.01 on 2nd August 2017 as per The Long Paddock – Queensland Government.

 

Summary by: Climate Prediction Center / NCEP  Dated 31st July 2017

ENSO Alert System Status: Not Active

ENSO-Neutral conditions are present.*

Equatorial sea surface temperatures (SSTs) are near-to-above average across the central and east-central Pacific Ocean.

ENSO-Neutral is favored (50 to ~55% chance) into the Northern Hemisphere winter 2017-18.*

* Note: These statements are updated once a month (2nd Thursday of each month) in association with the ENSO Diagnostics Discussion, which can be found by clicking  here

As per BOM -Australia 1st August 2017


ENSO neutral conditions are likely to persist – ENSO Outlook Inactive:

All earlier updates are listed below:

Click here for Update “Theoretically El Nino Not Possible During The Indian Southwest Monsoon 2017”

Click here for Update “Full Fledged El Nino Not Possible During The Indian Southwest Monsoon 2017”

Click here for Update “ENSO Neutral Conditions At End Of February 2017”

Click here for Update “2016/17 Qualifies As A La Nina Event”

Click here for Update “Enso Neutral Conditions At End Of October 2016”

Click here for Update “Full Fledged La Nina Not Possible During 2016”

Click here for Update “Demise Of El Nino Brings ENSO Neutral Conditions At End Of July 2016”

Click here for Update “Moderate El Nino Persists Till End Of May 2016”

Click here for Update “Strong El Nino Persists Till April 2016”

Click here for Update “NOAA ERSST.v4 & ERSST.v3b & Effects On ENSO Events”

Click here for Update “Yet A Weak El Nino – 6th June  2105”

Click here for Update “El Nino Update – 5th May 2015”

Click here for Update “Weak El Nino Develops March 2015”

Click here for Update “El Nino Status – 6th March 2015”

Click here for Update “El Nino Status – 7th February 2015”

Click here for Update “El Nino Status – 6th January 2015”

Click here for Update “El Nino Status 6th November 2014”

 

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