Full Fledged El Nino Not Expected During Indian Southwest Monsoon Season 2023 – NOAA Criteria Requires ONI >= +0.5ºC For A Period Of At Least 5 Consecutive Overlapping 3-Month Seasons
2023 ના ઇન્ડિયા ના દક્ષિણ પશ્ચિમ ચોમાસા દરમિયાન વિધિવત એલ નિનો ની શક્યતા નથી – NOAA ની વ્યાખ્યા મુજબ ONI >= +0.5ºC સળંગ પાંચ ત્રી માસિક સીઝન રહેવું જોઈએ
Enso Status on 4th June 2023
Enso Neutral conditions have prevailed for the last three 3-monthly seasons JFM ONI at -0.4ºC, FMA ONI at -0.1ºC and MAM 2023 ONI at +0.1ºC.
Ashok Patel’s Analysis & Commentary :
Enso Neutral conditions have prevailed for the last three 3-monthly seasons JFM ONI at -0.4ºC, FMA ONI at -0.1ºC and MAM 2023 ONI at +0.1ºC. The Nino3.4 SST March 2023 was +0.13ºC and April was +0.39ºC. Assuming very speedy heating of the Nino3.4 region, the earliest an El Nino thresh hold can be achieved would be end of June 2023 if the Nino3.4 SST for June reaches/crosses +0.84ºC, so that AMJ ONI can reaches/crosses +0.5ºC. NOAA criteria stipulates that a Full fledged El Nino requires five 3-monthly seasons with ONI => 0.5C, which can only be achieved earliest at the end of October 2023 if the AMJ ONI can achieve => +0.5ºC. Hence it can be concluded that a full fledged El Nino is not possible during the Indian Southwest Monsoon season which starts from June 2023 and ends at the end of September 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 had been +106% of LPA at the end of 30th September 2022. 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.
અશોક પટેલ નું તારણ અને વિશ્લેષણ :
છેલ્લા 3 મહિના થયા એન્સો ન્યુટ્રલ કંડીશન ચાલુ છે. ત્રિમાસિક JFM ONI -0.4ºC છે, FMA ONI -0.1ºC છે અને MAM 2023 ONI +0.1ºC છે. Nino3.4 SST March 2023 +0.13ºC હતું અને April +0.39ºC હતું. Nino3.4 વિસ્તાર ઝડપ થી ગરમ થાય તેમ ધારીએ તો પણ એલ નિનો થ્રેશ હોલ્ડ વહેલા માં વહેલું જૂન 2023 આખર માં થઇ શકે. NOAA ના નિયમો મુજબ આવા 5 મહિના એલ નિનો થ્રેશ હોલ્ડ જળવાય રહેવો જોઈએ જે વહેલા માં વહેલું ઓક્ટોબર 2023 માં પ્રસ્થાપિત થઇ શકે. ત્યાં સુધી માં ઇન્ડિયા નું ચોમાસુ પૂરું થઇ જશે. (ચોમાસુ હોય જૂન થી સપ્ટેમ્બર 2023)
આગળ ના 100 વર્ષ થી વધુ ની શરેરાશ પ્રમાણે એલ નિનો વર્ષ માં ભારતીય ચોમાસુ 94% રહેલ છે, જયારે લા નિના વર્ષ માં ચોમાસુ 106% રહેલ છે. ભારતીય ચોમાસા માટે વિવિદ્ધ પરિબળો પૈકી નું એલ નિનો/લા નિના ફક્ત એક પરિબળ છે. ભારત ના અલગ અલગ વિસ્તારો ના ચોમાસા પર એલ નિનો/લા નિના ની અસર એક સરખી નથી થતી, જે હાલ રિસર્ચ નો ઠોસ વિસય છે.
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).
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
The last La Nina 2021-23 ONI Index were JAS 2021 -0.5ºC ASO 2021 -0.7ºC SON 2021 -0.8ºC, OND 2021 -1.0ºC, NDJ 2021 -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, OND 2022 -0.9ºC, NDJ 2023 -0.8ºC, DJF 2023 -0.7ºC and the Current Enso Neutral ONI Index are JFM 2023 -0.4ºC, FMA 2023 -0.1ºC, MAM 2023 +0.1ºC
Latest Oceanic Nino Index Graph Shows
Enso Neutral Condition Exists End Of May 2023
The Table below shows the monthly SST of Nino3.4 Region and the Climate adjusted normal SST and SST anomaly from July 2021. Climate Base 1991-2020. ERSST.v5
Period Nino3.4 ClimAdjust YR MON Temp.ºC Temp.ºC ANOM ºC 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 25.75 26.60 -0.86 2023 1 25.84 26.55 -0.71 2023 2 26.30 26.76 -0.46 2023 3 27.19 27.29 -0.11 2023 4 27.96 27.83 0.13 2023 5 28.33 27.94 0.39
Indications and analysis of various International Weather/Climate agencies monitoring ENSO conditions is depicted hereunder:
Summary by: Climate Prediction Center / NCEP Dated 30th May 2023
ENSO Alert System Status: El Nino Watch
ENSO-neutral conditions are observed.*
Equatorial sea surface temperatures (SSTs) are near-to-above average across most of the Pacific Ocean.
A transition from ENSO-neutral is expected in the next couple of months, with a greater than 90% chance of El Niño persisting into the Northern Hemisphere winter.*
* 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.
Recent (preliminary) Southern Oscillation Index values as per The Long Paddock – Queensland Government.
30 Days average SOI was -16.18 at the end of May 2023 and was -17.54 on 3rd June 2023 as per The Long Paddock – Queensland Government and 90 Days average SOI was -7.15 on 3rd May 2023.
SOI Monthly graph up to May 2023 as per The Long Paddock – Queensland Government.
Southern Oscillation Index
As per BOM, Australia:
The 30-day SOI has maintained a negative value over the past fortnight, and both the 30-day and the 90-day SOI continue to demonstrate a gradual decreasing trend. The 30-day Southern Oscillation Index (SOI) on 1st June 2023 was -19.1
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.
As per BOM – Australia 23rd May 2023
Enso Outlook
El Niño WATCH – eastern tropical Pacific warming but little atmospheric response
The Pacific Ocean is currently ENSO-neutral (neither La Niña nor El Niño). Sea surface temperatures are warmer than average in the west and the east of the tropical Pacific. While all international climate models indicate it is very likely that tropical Pacific Ocean temperatures will reach El Niño thresholds during the southern hemisphere winter, an atmospheric response is also required for an El Niño to be declared. Thus far, little shift has been observed in atmospheric ENSO indicators with trade winds and cloudiness patterns in the Pacific remaining indicative of ENSO-neutral conditions. The 30-day SOI has dropped below the El Niño threshold, but sustained values are required for it to be considered a part of an El Niño response.
The ENSO Outlook remains at El Niño WATCH. This indicates there is an increased risk of an El Niño occurring this year, at least double the usual chance. History shows that when the ENSO Outlook has reached El Niño WATCH, El Niño has subsequently developed in about half of those years.
International Climate Models suggest further warming of the central and eastern tropical Pacific Ocean is likely. By July, all surveyed models indicate El Niño thresholds for sea surface temperatures will be met or exceeded. El Niño typically suppresses rainfall in eastern Australia during the winter and spring months.
(Note: winter and spring months are with reference to Southern Hemisphere)
