CEO’s Take: When IMD says, its Monsoon; When Skymet says, it’s not

CEO’s Take: When IMD says, its Monsoon; When Skymet says, it’s not

02:08 PM

G for Government, G for God…
It might rain, it might not..
When IMD says its Monsoon, and when Skymet says it’s not…

Jatin_Singh-Just as the Monsoon buzz was exponentially growing louder and shriekier, the government of India decided to declare the onset of Monsoon 2016.

Anyway, what could be a better day than today. While playing another social media battle in the wee hours of the day, I realized that people and particularly the all dedicated Twitterati need to be explained certain prerogatives of the government and few characteristics of the Monsoon. The two things that have kept me preoccupied at the moment.

Before getting onto the progress and behavior of Monsoon 2016, I would like to emphasize that Monsoon onset is an objective criterion applied subjectively.

Reiterating myself, Monsoon behaves in a truant manner. The onset phase leaves many questions unanswered. The onset of Monsoon, just like its other aspects, is a complex phenomenon involving extensive research.

Generally, Monsoon is declared after May 25. In fact, Monsoon can be declared any time post May 10 and looking at its further progress can be withdrawn as well. Yes, the decider of many fates, the life, and death factor of many sometimes is nothing less than an amusement.

For records, before declaring the onset of Monsoon in Kerala we should follow certain guidelines, which revolve around changes in rainfall, wind pattern, humidity and outgoing longwave radiation (OLR).

I have said earlier as well that the onset of Monsoon is functional with some parameters and should be declared only after conforming to these standards. Said it earlier and saying it again, compliance to all the criterion simultaneously to the copybook effect is generally difficult to attain.

Skymet Weather had predicted the onset of Monsoon between May 28 and 30. At a time when Skymet Weather had declared the onset of Monsoon, all the criteria were met barring the OLR value.

The rainfall criterion mentions that at least 60% of the 14 weather stations across Kerala and coastal Karnataka should record 2.5 mm rainfall or more for two consecutive days. Rainfall figures had well exceeded the requirement in the weather stations of Minicoy, Amini, Kollam, Thiruvananthapuram, Kannur, Punalur, Alappuzha, Kottayam, Kochi, Thrissur, Kozhikode, Thalassery, Kudlu and Mangalore.

Secondly, the depth of the westerly winds had also met the benchmark of 600 hPa or 12000 ft high from the equator to 10°N Latitude and between Longitude 55°E and 80°E.

The zonal wind speed over the area was also above 15 knots for two consecutive days. Take a look at the wind speed from May 24 to 31:

Wind speed

Only the OLR was slightly above the threshold of 200 Wm-2 in the box confined by Latitude 5-10°N and Longitude 70-75°E. Nevertheless, it was hovering around 200 Wm-2.

Here’s a look at the OLR values from May 24 to 31:


Now my question is, has the OLR bet been confirmed now? Take a look:

olr new

The OLR value has still not been met for consecutive two days! But its Monsoon onset for India.

Monsoon will now quickly progress to cover Mumbai by June 11 and probably entire Northeast India. Just as all of you, we will eagerly track its gait and nuances.

Featured image credit - skyscrapercity.com

Please Note: Any information picked from here must be attributed to skymetweather.com


8 thoughts on “CEO’s Take: When IMD says, its Monsoon; When Skymet says, it’s not




    Even if we got good rains before the official announcement of monsoon by IMD, it was just from western direction. Now (from 07/06/16) onwards it is raining from south-west direction.

  3. Siddharth Surana

    Coincidentally, I was traveling in these areas of Kerala during 28th May – 5th Jun. First N-S Kunnur to Kovalam to Kanniyakumari along the coast, then up in hinterlands to Kottayam, Kumarakom, Moonar and Kochi. On 28-29th Found medium intensity rains uptill Ernakulam/Kochibut nothing after that. In fact was fortunate to have had two open sky days in Kovalam beach repsort. Kanyakumari on 31st was bone dry. Stop-start rains with some forceful showers forced us to stay large indoors in Kumarakom on 1, 2 June whereas Moonar was pleasant for outdoors on 3-4 June barring a stray light shower. Cochin on 5th was cloudy, expectantly humid and glum just like Bombay is right now. Interested in weather as I am, I kept asking locals if fabled Kerala rains have begun, the unanimous answer was “This is just the trailer, real rains are yet to come.”

  4. Manoj

    Interesting and informative. Weather forecasting has certainly come a long way in India. Remember a time when as a kid we could safely assume the exact opposite of what the weatherman predicted! Then IMD was the only player in the field. Now we have Skymet to add to the competition and now predications are coming very close to being accurate.

  5. Saravana

    We have very healthy arguments about the criteria. This may further yield to understand other criteria which was not observed until now, may be significant influential factor for predicting the monsoon….which will reduce further variance in our prediction and help India major renewable energy – AGRICULTURE. Thanks for all the efforts.

  6. SRV

    Very informative and interesting. India needs such scientific and technology based information to improve agriculture and meet energy needs. Thank you.

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