Monsoon 2019 has been at its best for the last many days, with torrential rains triggering floods across central and southern parts of the country. With this, countrywide seasonal rainfall deficiency has also become normal with mere deficiency of 1%, which would also be covered soon.
All thanks to the favourable weather conditions, which led to formation of back to back Monsoon systems such as low pressure areas and even depression. What damage El Niño had done to June has now being covered up. But does that mean El Niño effect has finished. Well, the answer is no.
El Niño has declined but it is very much prevailing. The improvement of rains during the last few days can be attributed to the presence of strong and positive IOD (Indian Ocean Dipole) as well as MJO (Madden-Julian Oscillation) which has been passing through Indian Ocean. These weather phenomena are linked with good Monsoon rainfall, and presence of both together was able to negate the effect of El Niño.
However, situation has now changed once again, with Monsoon heading towards a leaner phase.
According to weather, the equatorial sea surface temperatures (SST) continue to fluctuate. These temperatures are above average across western and central Pacific Ocean, while they are near to below average across Eastern Pacific.
In fact, the latest Oceanic Niño Index (ONI), which is three months running mean of SST anomaly in the Niño 3.4 region, also stood at 0.5°C. This is the straight ninth episode, wherein ONI has been settling over the threshold value.
This means that we are still in El Niño conditions, although they are declining. The probability of El Niño is around 30% through August and further dipping thereon.
Weather models are indicating that there is still more than a month to go before we enter ENSO neutral conditions. These non-uniformities indicate warm potential of the sea, that indicates that El Niño still has the power to impact Monsoon rains.
Further, with MJO moving out of Indian Ocean in Phase 4, IOD would be left alone to battle much stronger El Niño. IOD along with MJO can put a tough fight but alone, it would be difficult to overpower El Niño, which is much stronger in nature.
Thus, country would be soon witnessing significant decrease in the Monsoon rains in the coming days. As per weathermen, rains would start reducing and probably Monsoon would go silent now. We are afraid that these conditions might persist for at least a fortnight. Chances are there that August might end on a similar note. Any good chances of revival are expected in September.
As a result, seasonal Monsoon deficiency would again make a comeback.
Image Credit: NDTV
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