‘Double Dip’ La Nina Expected To Enter Into 2023

Enso Status on 9th January 2023

OND 2022 ONI Index is -0.9ºC. The ‘Double Dip La Nina’ continues to persist at the end of December 2022 and is expected to enter into 2023.

Ashok Patel’s Analysis & Commentary :


Using NOAA Criteria, the La Nina thresh hold was first met in JAS 2021 with Oni Index of -0.5ºC, however, the full fledged La Nina event was confirmed at the end of January 2022 having fulfilled the five consecutive overlapping 3-monthly seasons with ONI less than or equal to –0.5ºC. La Nina has continued for more than a year, December 2022 being the 16th 3-monthly season with OND 2022 at –0.9ºC. This La Nina event is called a ‘Double Dip La Nina’.  See https://www.noaa.gov/news/double-dip-la-nina-emerges wherein NOAA mentions “Consecutive La Ninas following a transition through ENSO neutral conditions are not uncommon and can be referred to as a “double-dip.”
The First La Nina event was in 2020-21 which was followed by a second La Nina the current event of 2021-22 with a transition through Enso Neutral Conditions in 2021.

The Double Dip La Nina is expected to enter into 2023.

Indian Monsoon & Enso relationship for India:

Based on earlier more than 100 years weather Data for Indian Summer Monsoon, The Average Rainfall in an El Nino years is 94% of LPA while in La Nina Years it has been 106 % of LPA for the whole country. Monsoon Rainfall over India has been +106% of LPA at the end of 30th September 2022. However, El Nino or La Nina may affect the Monsoon differently for different Regions of India and warrants research for concrete co-relations for each region of India if any.

How ONI is determined:

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 further improved homogeneous historical SST analyses (Extended Reconstructed SST – ERSST.v5). Explanation about ERSST.v5 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.

The Climate Prediction Center (CPC) is a United States Federal Agency that is one of the NECP, which are a part of the NOAA
Current La Nina 2021-22 all ONI Index are JAS 2021 -0.5ºC ASO 2021 -0.7ºC SON 2021 -0.8ºC, OND 2021 -1.0ºC, NDJ 2022 -1.0ºC, DJF 2022 -1.0ºC, JFM 2022 -0.9ºC, FMA 2022 -1.0ºC, MAM 2022 -1.1ºC, AMJ 2022 -1.0ºC, MJJ 2022 -0.9ºC, JJA -0.8ºC, JAS 2022 -0.9ºC ASO 2022 -1.0ºC SON 2022 -1.0ºC and OND 2022 -0.9ºC.

Latest Oceanic Nino Index Graph Shows
Double Dip La Nina 2021-22 Exists End Of December 2022

 

The Table below shows the monthly SST of Nino3.4 Region and the Climate adjusted normal SST and SST anomaly from June 2020. Climate Base 1991-2020. ERSST.v5

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

2020   6   27.39   27.73   -0.34
2020   7   26.99   27.29   -0.30
2020   8   26.27   26.86   -0.59
2020   9   25.89   26.72   -0.83
2020  10   25.46   26.72   -1.25
2020  11   25.28   26.70   -1.42
2020  12   25.45   26.60   -1.15
2021   1   25.56   26.55   -0.99
2021   2   25.76   26.76   -1.00
2021   3   26.50   27.29   -0.80
2021   4   27.11   27.83   -0.72
2021   5   27.48   27.94   -0.46
2021   6   27.45   27.73   -0.28
2021   7   26.90   27.29   -0.39
2021   8   26.32   26.86   -0.53
2021   9   26.16   26.72   -0.55
2021  10   25.78   26.72   -0.94
2021  11   25.76   26.70   -0.94
2021  12   25.54   26.60   -1.06
2022   1   25.61   26.55   -0.95
2022   2   25.88   26.76   -0.89
2022   3   26.33   27.29   -0.97
2022   4   26.72   27.83   -1.11
2022   5   26.83   27.94   -1.11
2022   6   26.98   27.73   -0.75
2022   7   26.60   27.29   -0.70
2022   8   25.88   26.86   -0.97
2022   9   25.65   26.72   -1.07
2022  10   25.73   26.72   -0.99
2022  11   25.80   26.70   -0.90
2022  12   25.71   26.60   -0.89

Summary and Outlook from Various Agencies:

Southern Oscillation Index

As per BOM, Australia:

The 30-day Southern Oscillation Index (SOI) to 7th January 2023 was +22.1 and is considered in the La Nina zone.

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

Recent (preliminary) Southern Oscillation Index values as per The Long Paddock – Queensland Government.

30 Days average SOI was +18.41 at the end of December 2022 and was +20.82 on 9th January 2023 as per The Long Paddock – Queensland Government and 90 Days average SOI was +14.02 on 9th January 2023.

SOI Monthly graph up to December 2023 as per The Long Paddock – Queensland Government.

Summary by: Climate Prediction Center / NCEP  Dated 8th December 2022

ENSO Alert System Status: La Niña Advisory
La Niña is present.*
Synopsis: La Niña is expected to continue into the winter, with equal chances of La Niña
and ENSO-neutral during January-March 2023. In February-April 2023, there is a 71%
chance of ENSO-neutral.

* 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 4th January 2023