How’s the josh of the South West monsoon looking?
As we write, things look a little overcast. In reality and in terms of data.
In the first 17 days of the June-September monsoon, we have had 43.2 mm of rainfall. That’s a 43% rainfall deficiency compared to the normal weightage average of 76.2mm. And, of the 36 meteorological sub-divisions, there have been deficit rains in 31, so far.
Early last month, we wrote an article on El Nino and the Fate of Agri Commodity Prices. In it, we mentioned how the El Nino is expected to be an unwelcome guest this year; we also talked about why this mischievous weather formation could upset everything from the onset and extent of the monsoon in India to agricultural patterns and commodity and stock prices.
Now the monsoons have arrived about a week late in Kerala and the quantum of rainfall is deficient so far…
Does this mean we’re doomed?
Hold your horses. The IMD still sticks by its forecast of a ‘normal monsoon’.
So, what could be giving our official weather bureau this confidence? It could be the Indian Ocean Dipole – popularly known as the Indian Niño!
What’s the IOD?
The Indian Ocean Dipole (IOD) is the Indian Ocean’s counterpart of the Pacific El Niño and La Niña. The term Dipole means two “poles” or two areas of differences. And by that logic, the IOD measures differences in Sea Surface Temperature (SSTs) between the Arabian Sea (western pole) and the Eastern Indian Ocean south of Indonesia (eastern pole).
A positive phase signifies a warmer-than-normal Western IO and cooler-than-normal Eastern IO, while the negative phase indicates the opposite. Neutral IOD conditions indicate normal temperatures in the Western and Eastern IO.
How does it impact the Indian monsoon?
Theoretically, research has shown that a positive IOD (+IOD) generally is good for the Indian Summer Pre-monsoon Rainfall (ISMR) and could suggest a good monsoon too.
Source: Bom.gov.au, Ventura Securities
In general, the IOD has three phases: neutral, positive and negative. It begins with a neutral phase, which governs weather patterns in May and June. Then, it turns positive in August and October and finally, there is a rapid decline in the monsoon when the IOD turns negative post October.
Clash of the Tidal Titans
As per data from the Bureau of Australian Meteorology, the IOD index has been positive for the past three weeks. In fact, the latest weekly index value (ending 9 June) is +0.67 °C (Positive), which is good news for the Indian monsoon!
However, this year, El Nino, which usually plays spoilsport for the Indian Monsoon, is quoting above the positive threshold value of 0.77. It suggests a 60% chance of El Nino adversely impacting the South West Indian Monsoon.
In the battle between the El Nino and the IOD, who will be victorious? Does the IOD have the potential to offset the ill-effects of an El Nino season and deliver normal rainfall to India?
Rallies of the past
History paints a mixed picture of the outcome of the clash of these two tidal titans.
In recent times, we have had positive IOD years in 1982, 1994, 1997, 2003, 2007, 2008, 2012, 2015.
Of these, El Nino simultaneously occurred in 1994, 1997 and 2015
Source: Bom.gov.au, Ventura Securities
In 1997, when the IOD was positive, the monsoon was close to normal, despite a record-breaking El Nino reading. However, on the other hand, in 2015 a similar pattern developed (+IOD and El Nino) and during this period, rainfall was below normal or in fact, tending to drought.
So, what’s it going to be in 2019?
And the winner is…
With both events (+IOD and El Nino) occurring simultaneously this year, they have evened out each other’s odds, in a sense. Recent history suggests that the results in such a situation are akin to a toss of a coin. However, we would back the wisdom of the IMD, which has taken into account various factors, including perhaps the recent Cyclone Fani that will drive down temperatures in the Eastern IO, accelerating the IOD index rise and facilitating a normal monsoon.
Disclaimer: Ventura Securities Ltd has taken due care and caution in compilation of data for its web blog. The information has been obtained from different sources which it considers reliable. However, Ventura Securities Ltd does not guarantee the accuracy, adequacy or completeness of any information and is not responsible for any errors or omissions or for the results obtained from the use of such information. Ventura Securities Ltd especially states that it has no financial liability whatsoever to any user on account of the use of information provided on its web blog. The information provided herein is just for the knowledge purpose and shouldn’t be construed as investment advice under any circumstances.