El Nino is currently neutral. However, key atmospheric and oceanic indicators are pointing at a stronger El Nino during the Indian Summer Monsoon. The latest model run reveals a clear spike, bigger than its last projection during the early days of April. There is about twice the normal likelihood of El Nino forming in any year. Therefore, caution of El Nino 'WATCH' continues.
ENSO: The -VE sea surface temperature (SST) anomalies in the central-eastern equatorial Pacific Ocean have weakened further. The Weekly Nino 3.4 index, which was stuck at 0.0 degrees, has marginally increased to 0.1 degrees now. However, the Nino 1+2 index value has reached + 2.7 degrees for two consecutive weeks, indicating significant warming along the South American coast.
The explosive warming off the South American coast suggests similar changes trickling down the equatorial Pacific in the neighbouring Nino regions. Nino 3.4 region remains the principal measure for monitoring, assessing and predicting ENSO.
IOD: Indian Ocean Dipole is currently at the lower end of positive neutral. Earlier, the index had reached very close to the +VE threshold of +/0 0.4 degrees. Two successive values of 0.38 degrees and 0.36 degrees were recorded on 19th Mar and 26th Mar respectively. The latest IOD index value for the week ending 16 April 2023 was 0.18 degrees, which is within neutral bounds. Strong +VE IOD assures decent monsoon bursts, irrespective of the state of other oceanic concerns. Model projections at this time of the year are not considered accurate. The latest model run depicts a 'bell' shaped curve with a gradual rise during the first half of the monsoon and a steady decline in the latter half.
MJO: Madden Julian Oscillation is presently in Phase-8 over Africa region. It is decelerating and also shrinking in amplitude, over the next 2 weeks. It is likely to travel over the equatorial Indian Ocean with minimal implications till 1st week of May. Indian seas have gone without a cyclone in the pre-monsoon season so far. Weaker MJO will remain inconsequential for the development of any tropical storm on either side of the Indian coastline.
Southwest Monsoon is getting closer to its timeline. The shadow of El Nino does not seem to be diluting. Rather, the probability is becoming bigger and stronger, more so, mid-way through the season. Core monsoon months continue to be at risk of impairment.
