Sunday, March 31, 2019

Importance of Monsoon Forecast for India:

Indian economy is basically agriculture based, and agri business and economy depend a lot on the South West Monsoon. Agriculture contributes a major part to the GDP.
Hence, getting information and forecast of the Monsoon to the farmers and concerned departments well in advance is of prime importance. The agri industries need to plan cropping patterns and farmers need to plan purchase and storage of seeds and fertilisers.


Now, IMD issues its first SWM forecast around mid April. The April forecast indicates the likely amount of rain throughout India , on the whole, and does not detail its distribution region wise. 
A forecast of regional distribution is necessary for water management and reservoir capacity storage. 
The second forecast and rain estimate is issued in June. By that time, sowing is already complete, and an adverse situation could be disastrous. Saving water stressed seedlings becomes a priority with urgent irrigation. One Fourth of the SWM is over by then.


Vagaries' Views:

The SWM forecast should be issued earliest by beginning April. It could be made by analysing the weather parameters developing as on that date in early April, and subsequently monitor the developments as they happen and issue comments on how the monsoon is likely to progress.  The  Monsoon Watch series in Vagaries begins with this concept..and charting the progress periodically, the Monsoon Watch Series indicates the +ves and the -ves in the ensuing progress. 
Initially Vagaries (MW Series) forecasts only the arrival date. And that is of prime importance. A belated advance could be fore warned, and help the farmer in delaying the sowing and saving his crops. Or later in the season, a prolonged withdrawal could be bad for the crops too, and should be forecasted and informed early. 


The quantum is taken up later on.
Though a proper estimate of quantum of rain and regional distribution must be estimated. If, for example, we have 120% of the normal precipitation, that is 20% excess, in say the western state of Gujarat, and say, 80% normal, or 20% deficient in another state, IMD would declare a "normal" monsoon. That is because it takes the figures from the country as a whole. This, I feel depicts a wrong picture.

The most dangerous, or risky, is the " break Monsoon" in the middle of the season. This has to be estimated and informed as correctly as possible, as it holds the key to proper crop and water planning.
In such cases the agriculture ministry must be prepared to support proper irrigation and supply in July or August.
For such fore warnings, the IMD issues a forecasted estimate by the time the Monsoon is half over.

Now, recently,The Japanese Agency for Marine Earth Science and Tech. has forecast below normal rains for Jun/July /Aug 2019, and another International Research Institute IRI at Columbia, have forecasted a near normal SWM for 2019. 

Whether true or false, our Met Department should take note of this seriously, and be prepared with the necessary steps to be taken. We just cannot wait till the IMD issues its "vague" forecasts. 


IMD maintains that it (SWM) cannot be forecasted so early, and that the Indian Monsoon system is too complicated. But let us understand, these foreign agencies also have a track record.


We cannot take risks with such an important event (SWM). An event that makes or breaks Indian Agriculture and Economy.

10 comments:

Abizer Kachwala said...

Excellent write-up by Rajesh Sir.

babu mathew said...

Exactly sir.. Thats why I am following vagaries of weather instead of imd for saving my crops. It has been helpful for me several times since i following you.. Thank you so much Rajesh sir. Of course eagerly waiting for the monsoon watch series.

Dr. Venu G. Nair said...

you said it Rajesh.

Dr. Venu G. Nair said...

You said it Rajesh

Rajesh Kumar said...

Waiting for MW Series 2019 by Rajesh Sir. Most important event for SWM forecast

NilaY Wankawala said...

Rajesh sir is saying this since years - I guess it doesn't get through deaf ears of IMD, nor they are so dumb to understand this ?

Really sad it goes unnoticed by IMD or they are under any pressure not to do so?

sset said...

Good article by Rajesh Sir....

Some comments from my side...
(1) IMD are government agencies, they may lack intense climate subject matter expert like Rajesh Sir, lack hardware/software for weather simulations. Today state of art is neural networks they may be using old statistical models. Requires people with exceptional mathematical intelligence. They may need to involve brains from IIT/ Google..

IMD typical government agencies usually are sluggish - typical 9-5 job.

(2) Article stresses on SWM - but what about NEM - nobody cares? Entire south east India has become horrible desert. 5 years of no rain. Entire south Andhra, entire interior south karnataka + northern part, entire Tamil Nadu barren.

(3) Every state irrespective of North or South requires rain - to grow food by farmers. Article says break monsoon is not good, but this triggers some showers for south east India - for right conditions.

(4) Today NEM has become 'non existent monsoon' always at mercy of SWM which refuses to stop till November, always at mercy of Western disturbances which does not allow any system to form near SE India.

Abizer Kachwala said...

IMD (may be )does forecast monsoon keeping in mind that positivity prevails ,government remains happy,share markets take the forecast positively...while caring for so many of factors,it releases its forecast,so it gets delayed.

NilaY Wankawala said...

CREDIT AUSTRALIAN GOVERNMENT BUREAU OF METEROLOGY

Issued 2 April 2019

The latest ENSO Wrap-Up and Climate Model Summary are now available on the Bureau's website.

El Niño ALERT—tropical Pacific Ocean warm but little atmospheric response

ENSO Outlook
Our ENSO Outlook provides
up-to-date information on the likelihood of an El Niño or La Niña developing.

ENSO Outlook dial showing El Niño ALERT status
Current status: El Niño ALERT

The Bureau's ENSO Outlook remains at El Niño ALERT. This means the chance of El Niño developing in 2019 is approximately 70%; around triple the normal likelihood.

Tropical Pacific sea surface temperatures have remained close to El Niño thresholds for the past five weeks. The atmosphere has responded to the surface warmth at times, but is yet to show a consistent El Niño-like response. For example, trade winds have varied between weaker-than-average and average strength.

Most international climate models predict tropical Pacific Ocean sea surface temperatures will remain at El Niño levels at least to mid-year. This would increase the likelihood of the tropical Pacific atmosphere and ocean reinforcing each other, and developing into a full El Niño, with the resultant changes in Australian and global weather patterns. Predictions made at this time of year have lower accuracy than those made in winter or spring and should be used with some caution.

El Niño typically brings drier than average conditions for eastern Australia during winter–spring, and warmer days across southern Australia. During the autumn months, the influence of El Niño tends to be weaker, but can bring drier conditions to the south of the country.

The Indian Ocean Dipole (IOD) has little influence on Australia from December to April. Model outlooks suggest the IOD is likely to remain neutral for the remainder of the austral autumn, with the possibility of a positive IOD in winter. A positive IOD typically means drier than average conditions for southern and central Australia during winter-spring.

More information

Media enquiries: (03) 9669 4057 media@bom.gov.au

Next update expected on 16 April 2019

sset said...

All of us blame on ENSO and 'break monsoon' but do you know this has its own benefits.

el-nino triggers rain for south America Peru which otherwise remain dry and devoid of rain during normal periods. Resource people are trying to establish connection between el-nino and 'north east monsoon' specially if this gives rains to south east India which otherwise has to suffer from successive droughts due to monsoon failure.

https://indianexpress.com/article/explained/how-rocks-in-meghalaya-cave-connect-northeast-monsoon-to-el-nino-5642566/

ENSO is known to have an impact on the winter monsoon as well but is weaker and opposite. The warming of sea-surface waters, for example, is seen to help winter rainfall rather than suppressing it. The impact varies in time and space. The influence is weaker in October and stronger in November and December. Similarly, the rainfall over southeastern peninsular India and Sri Lanka is strengthened with warming ocean, but is diminished over Thailand, Vietnam and the Philippines.

MUMBAI SCZ (Vile Parle) .. year 2019 till now  A) Monthly weather averages 2019 ( Coolest month .. Jan @ 23.6 c , Warmest month .. Jun ...