Monsoon Updates

Oct, 03, 2018

For the first time, India gets its soil moisture map


Mains Paper 3: Agriculture| Major crops cropping patterns in various parts of the country, different types of irrigation and irrigation systems

From UPSC perspective, the following things are important:

Prelims level:  Rabi and Kharif Season, Variable Infiltration Capacity Model

Mains level: Utility of Moisture Mapping


Moisture Mapping

  1. With the Rabi season around the corner, a countrywide forecast is prepared at the end of the monsoon season.
  2. This forecast, following a joint exercise by IIT Gandhinagar and the India Meteorological Department (IMD), for the first time, provides a country-wide soil moisture forecast at seven and 30-day lead times.
  3. Soil moisture is crucial for agriculture since it directly affects crop growth and how much irrigation is required for the area.
  4. It suggests deficit soil moisture conditions are likely in Gujarat, Bihar, Jharkhand, Tamil Nadu and southern Andhra Pradesh.

Variable Infiltration Capacity Model

  1. The experts used the ‘Variable Infiltration Capacity’ model to provide the soil moisture prediction.
  2. The product, termed ‘Experimental Forecasts Land Surface Products’, is available on the IMD website.
  3. It has been developed using the hydrological model that takes into consideration soil, vegetation, land use and land cover among other parameters.
  4. The team has been working on high-resolution soil database that is essential for soil parameters used in the modelling.
  5. However, the database is not available for the entire country currently.

Why need Moisture Map?

  1. Crucial information needed for agriculture is not revealed only through rainfall data.
  2. Even if there’s a normal rainfall, if the temperature is abnormally high, it can rapidly deplete the soil moisture.
  3. So essentially soil moisture gives us more information on what is needed for crop growth in different parts of the country.
  4. Forecasting of soil moisture holds significance for the rabi season.
  5. As per official data, the total area sown under rabi crops is around 625 lakh hectares of which wheat takes up 300 lakh hectares.
  6. Timely soil moisture forecasts will help target interventions, in terms of seed varieties for better planning in agriculture.

Leap over Kharif uncertainties

  1. In Bundelkhand, most farmers keep their land fallow or just grow some fodder crop during the kharif season since the rains are unpredictable and there could be extended dry spells after sowing.
  2. They then mainly cultivate the rabi crop using the soil moisture left behind by the monsoon rains.
  3. It is a similar trend in Bihar, in low lying areas of Seemanchal and Kosi belt, where no crop is grown during Kharif because of inundated lands.
  4. This means that if there is not enough rainfall in one or two months, these are regions which will demand heavy irrigation whether that comes from groundwater or surface water storage (reservoirs).
  5. Based on observed conditions at present, Gujarat, parts of Maharashtra, Chhattisgarh, Jharkhand, Tamil Nadu and parts of Andhra Pradesh are deficient in terms of soil moisture right now.
Jun, 30, 2018

Monsoon covers country fortnight early


Mains Paper 1: Geography | Important Geophysical phenomena such as earthquakes, Tsunami, Volcanic activity, cyclone etc.

From UPSC perspective, the following things are important:

Prelims level: Monsoon dynamics, westerly winds, western disturbances

Mains level: Role played by the monsoon in Indian economy


Early monsoon arrival

  1. The Southwest monsoon has now covered the entire country, a fortnight ahead of its normal schedule of mid-July
  2. This has happened for the first time since 2015

Monsoon advance in India

  1. The monsoon trough will lie over the Himalayan foothills in the first week of July
  2. There was strong interaction between monsoon currents and dry westerly winds, which brought thundershowers and revived monsoon
  3. This was also supported by strong western disturbances, making the advance quicker
Jun, 12, 2018

What caused the Dec. 1, 2015 Chennai downpour?


Mains Paper 1: Important Geophysical phenomena, geographical features and their location- changes in critical geographical features

From UPSC perspective, the following things are important:

Prelims level: Cold Pool Theory

Mains level: This sought to be a better explanation for the floods in some unexpected regions.


IISc researcher answers this by linking the Eastern Ghats and rain-bearing clouds

  1. In December 2015 Chennai and its surrounding regions experienced an unprecedented, heavy rainfall.
  2. In a region where the average rainfall during the season is expected to be 8-10 mm per day, one of the rain gauges in the city recorded an abnormally high, 494 mm rainfall in over 24 hours that day.
  3. This led to death of nearly 250 people, and Chennai was declared a ‘disaster zone’.

Cold Pool Theory

  1. When clouds give out water droplets, the droplets evaporate mid-air, as they fall down. This cools the surrounding air, forming a cold pool of air which sinks down and flows horizontally
  2. The gusty cold wind that heralds an approaching thunderstorm is nothing but a cold pool, which plays a pivotal role in cloud dynamics.
  3. Unlike the Western Ghats, which run close to the west coast of India, the Eastern Ghats are nearly 200 km away from the coast.
  4. Therefore, the link between the mountains orography and the rainfall over the region is crucial.
  5. The cold pool was obstructed by the Eastern Ghats from flowing downward; hence it piled up and remained stationary over the Chennai region.
  6. The reason for the clouds remaining stationary was that there was a balance between the piling of cold pool along the mountain and the winds from the bay.

Dust storms: Aandhis in North India are too caused by ‘Cold Pool’

  1. Cold pools are known to play an important role in the dust storms (Aandhi) that form in northern India.
  2. They form by the evaporation of raindrops.
  3. This process is more efficient in the drier and warmer environment as there is lot of scope of evaporation.
  4. So, the cold pools that form in these conditions, are deeper and more vigorous.
  5. As pre-monsoon conditions in north India are very dry and warm, cold pools that accompany the pre-monsoon thunderstorms there are far more destructive, causing widespread damages.

The Way Forward

  1. For the first time, this study links cold pools and the mountain structure to explain rainfall over south India.
  2. Though the primary aim of the study is to explain the anomalous rainfall over Chennai on December 1, 2015, the understanding gained from this analysis can be useful for improving the general weather forecast over this region.
May, 17, 2018

Scientists develop new model to determine monsoon variations across India


Mains Paper 3: Science & Technology | Developments and their applications and effects in everyday life

From UPSC perspective, the following things are important:

Prelims level: Agencies Involved, MLR, El Nino, Indian Ocean Dipole, Equatorial Indian Ocean Oscillation (EQUINOO)

Mains level: Factors affecting Indian Monsoon and Utility of this weather model in studying them.


New model for estimating variability and trends in rainfall

  1. Scientists have developed a new model for estimating variability and trends in rainfall over different climate regions of the country
  2. The new statistical model based on multiple linear regression (MLR)
  3. It has been developed by scientists from the Centre for Oceans, Rivers, Atmosphere and Land Sciences (CORAL), IIT Kharagpur, the Indian Institute of Tropical Meteorology (IITM), Pune, and the Indian National Centre for Ocean Information Services (INCOIS), Hyderabad

Complexities in Predicting Monsoon Variability

  1. Indian monsoon, both southwest and northeast is complex
  2. It depends on various climatic forcings (conditions) like El Nino, Indian Ocean Dipole, which affect rainfall in different regions, in different ways
  3. Researchers highlight that current dynamic models used for monsoon forecast face two major problems
  4. First, they respond a little too much to El Nino Southern Oscillation (ENSO)
  5. Second, the relationship between Equatorial Indian Ocean Oscillation (EQUINOO) and summer monsoon in models has been found to be opposite to actual observation
  6. If we can improve our understanding of EQUINOO’s impact on monsoon, then we can make corrections in the dynamic model and improve our teleconnections. This will help us get an accurate monsoon forecast

Importance of this weather model

  1. The research is one of the first to have analyzed the variability of the Indian monsoon because of these factors together
  2. It confirmed with statistical analysis, that ENSO and EQUINOO are two major drivers for Indian monsoon and explain around 50% variability in monsoon
  3. Such studies would help scientists to better tune their models for accurate weather prediction
  4. The research assumes significance as the monsoon decides the livelihood of more than a billion people and influences the agrarian economy which is largely dependent on its accurate forecast
Apr, 18, 2018

[op-ed snap] Chasing the monsoon: Agriculture


Mains Paper 3: Agriculture | Different types of irrigation and irrigation systems storage

From UPSC perspective, the following things are important:

Prelims level: Particulars of the IMD, El Nino, La Nino, etc.

Mains level: What should be done by the Indian Government to increase the benefit of good monsoon?


Good news from the India Meteorological Department(IMD)

  1.  For farmers, the IMD’s estimate that rainfall during the summer, between June and September, will be 97% of the 50-year average of 89 cm, is bound to raise fresh expectations
  2. The forecast of a normal monsoon has brought relief all around
  3. The IMD’s decision to provide a more fine-grained forecast on the monsoon’s progress, particularly in the central and northern regions, will meet a long-felt need and can potentially guide farmers better

High crop output

  1. The normal monsoon is the third year in a row and farmers can look forward to a high output for a variety of crops
  2. What is well known is that a good monsoon raises agriculture’s contribution to GDP growth, while a drought year depresses it

Some positive steps taken by the government

  1. he Centre has been supportive of higher returns through the Minimum Support Price mechanism and additional bonuses have been announced by States such as Madhya Pradesh for procurement

What should be done by the government?

  1. Now that another year of good cropping is expected, and unremunerative prices will depress public sentiment,
  2. it is vital for the Centre to arrive at a policy that gives constructive advice to farmers on the ideal cropping mix and help them get the cost-plus-50% margin that it has promised them
  3. The long-term challenge is to make the most of the rainfall that India gets, ranging from a few hundred millimetres or less in the northwest to more than a few thousand millimetres elsewhere
  4. The Master Plan for Artificial Recharge to Ground Water drawn up by the Centre should be pursued scientifically, to help States with the most water-stressed blocks get adequate funds to build artificial recharge structures
  5. Moreover, for those farmers who choose to continue with wheat and rice, transfer of expertise and provision of equipment that enables efficient utilisation of water is vital

One of the main reasons of water stress in India

  1. An estimate of water used to grow rice and wheat, measured in cubic metres per tonne, shows that India uses more than what, say, China does
  2. In the case of cotton, the figures present an even more staggering contrast: 8,264 cubic metres for India, against 1,419 for China
  3. Combined with distortions in procurement subsidies, water stress due to such use is inevitable

The way forward

  1. Clearly, governments need to invest consistently to harvest the monsoon, both on the surface and underground, with community participation


India Meteorological Department

  1. The India Meteorological Department (IMD), also referred to as the Met Department, is an agency of the Ministry of Earth Sciences of the Government of India
  2. It is the principal agency responsible for meteorological observations, weather forecasting and seismology. IMD is headquartered in Delhi and operates hundreds of observation stations across India and Antarctica.Regional office are at Mumbai, Kolkata, Nagpur and Pune.
  3. IMD is also one of the six Regional Specialised Meteorological Centres of the World Meteorological Organization. It has the responsibility for forecasting, naming and distribution of warnings for tropical cyclones in the Northern Indian Ocean region, including the Malacca Straits, the Bay of Bengal, the Arabian Sea and the Persian Gulf
Oct, 09, 2017

Mapping the not-so-normal monsoon

Image source


Mains Paper 1: Geography | changes in critical geographical features (including waterbodies & ice-caps) & in flora & fauna & the effects of such changes.

From UPSC perspective, the following things are important:

Prelims level: Monsoon and its types, spatial and temporal distribution of rains, Kharif and Rabi seasons

Mains level: Heavy dependence of Indian agriculture on monsoon, impact of this dependence and remedial measures


Monsoon normal in 2017

  1. South-west monsoon for 2017, has turned out to be normal for the second consecutive year
  2. IMD deems the season ‘normal’ if the all-India quantum of rain falls within a 10% range of its long-period average of 887.5 mm
  3. The 2017 monsoon fell short of the number only by 5%
  4. But there can be many shades of grey to an officially ‘normal’ monsoon

Another bumper year?

  1. In 2016-17, India harvested a record crop of cereals and managed a quantum jump in its output of both pulses and oilseeds
  2. This contributed to a significant bump-up in the agriculture leg of the GDP which grew 4.9% in FY17 compared with 0.7% in FY16
  3. But expecting an encore of that impressive performance just because this year’s monsoon has turned out ‘normal’, would be unrealistic
  4. More than the quantum of rainfall that is dumped on the sub-continent during the four critical months, it is the spatial and temporal distribution of rains that make or break crop prospects
  5. On this score, the 2017 monsoon has been quite whimsical

Patchy distribution

  1. For the purposes of measuring the spatial spread of rainfall, the IMD categorises India into 36 meteorological sub-divisions
  2. IMD’s wrap-up of the recent monsoon season tells us that 5 of India’s 36 sub-divisions received excess rains, 25 received normal rains and 6 witnessed deficient rains
  3. But the devil really lies in the details and the identity of the States that suffered deficient rains really matter to crop prospects
  4. This year’s monsoon has played truant in some key food-bowl States
  5. West Bengal, Uttar Pradesh and Punjab account for a lion’s share of kharif rice production. But this year’s monsoon has been 29% below normal in Uttar Pradesh and 22% short of normal in Punjab
  6. Madhya Pradesh, which is a critical growing region for the rabi wheat crop, has seen a deficiency of 20%. This will also impact pulses output.

Weak ending

  1. Rainfall in the last two months of the south-west monsoon dictate reservoir storage and soil moisture
  2. This sets the tone for the planting of the winter crops
  3. The rabi season accounts for the whole of India’s wheat and gram harvest, a fourth of the output for coarse cereals and chips in with over a third of the yearly harvest of urad and moong
  4. Oilseeds such as rapeseed and mustard, sunflower and safflower are also predominantly winter crops
  5. Therefore, dry spells in the latter half of this monsoon, taken with deficient rains in key rabi growing regions, can make for less than rosy rabi prospects
Jun, 07, 2017

El Nino is weaker than anticipated, says IMD


Mains Paper 1: Geography | Salient features of world’s physical geography

From UPSC perspective following things are important:

Prelims level: El Nino, La Nino and IOD concepts.

Mains level: These kind of phenomenons are important for the static part of the syllabus. Expect a direct question
if already not asked


  1. What: The India Meteorological Department(IMD) is expecting better this year
  2. Why: Because El Nino would be much weaker than anticipated
  3. New monsoon forecast system: IMD has shifted to a new monsoon forecast system, called a dynamical model that works by supercomputers simulating the weather and extrapolating it(i.e. Deducing the weather by assuming that existing trends will continue)

What is El Nino?

  1. The El Nino is characterised by surface waters of the equatorial Pacific warming up by more than half a degree
  2. It is known to negativey affect monsoon rain every six out of 10 years
  3. A positive Indian Ocean Dipole (IOD) is said to buffer the impact of El Nino and contribute to better rains
  4. The Indian Ocean Dipole (IOD) is also known as the Indian Niño. IOD is an irregular oscillation of sea-surface
    temperatures in which the western Indian Ocean becomes alternately warmer and then colder than the
    eastern part of the ocean
  5. The IOD is a swing in surface temperatures that turns the western Indian Ocean alternately warmer and then
    colder than the eastern part of the ocean
Oct, 27, 2016

Northeast monsoon to set in by October 30: IMD

  1. Arrival of: The northeast monsoon, which brings the bulk of rainfall in Tamil Nadu and other southern States
  2. Date: It will commence by October 30, according to the India Meteorological Department
  3. Last year, the northeast monsoon wreaked havoc in Tamil Nadu, with a record downpour in December 2015
Oct, 03, 2016

India got 3% less rain than normal: IMD

  1. IMD: India has ended up with 3% less rain than normal during the monsoon months of June to September
  2. This is the first time since 2011 that the IMD was not able to forecast the overall ‘sign’ of the monsoon
  3. It expected heavy rain but ended up with less than normal
  4. In 2014 and 2015, it could not anticipate the severity of the droughts but had indicated that monsoon would be below normal
  5. In 2011, the IMD said India would get below normal (95% of the average) rain, but the country ended up with 2% more rain than normal
Sep, 20, 2016

Monsoon to be normal: IMD

  1. The India Meteorological Department (IMD) said the monsoon will be normal this year
  2. It has gone back on its earlier forecast of above normal monsoon
  3. Why? Due to delay in La Nina weather pattern
  4. Background: India has been hit by drought in the last two years, with the last monsoon being affected by El Nino
  5. However, it was expected that this year there would be a gradual transition to La Nina phenomenon, which would have boosted monsoon and given excess rain in September

Discuss: Discuss the significance of the normal monsoon rains on Indian economy. How good rains should be used to recharge groundwater through policy means?

May, 26, 2016

Australia signals end of El Nino

  1. Context: Australia’s current climate model suggest that La Nina will begin in second half of monsoon
  2. La Nina: Reverse condition of El Nino
  3. El Nino: A warm current replaces cold current in tropical pacific region and affect the Indian monsoon
  4. La Nina will bring heavy rains over India
  5. Effects: Good for Kharif crops, the area under crops is expected to increase
May, 19, 2016

Cyclonic storm over Bay of Bengal to intensify: IMD

  1. Context: Season’s first cyclone will be brought by cyclonic depression form in Bay of Bengal
  2. Effect: Will bring rain fall in Kerala, Chennai and Andhra Pradesh
  3. Conditions are favourable for advance southwest monsoon in some parts of Bay of Bengal, entire south Andaman Sea and Nicobar Islands
  4. The forecast of delayed monsoon in Kerala remains same
May, 16, 2016

Remnants of El Nino holding up monsoon- II

  1. Signs of Monsoon: Raining over Andman with Cyclones in month of May
  2. But raining over Andman is decreasing because they are not sufficiently fuelled by cross equatorial flows
  3. No cyclones have been seen seen yet
  4. Prediction: Lag in seasonal transition, pre monsoon rains over Tamil Nadu and Kerala around 1 June
  5. Earlier: IMD predicted that there would be rains early than usual and above normal level and 106 % of 89 cm
May, 16, 2016

Remnants of El Nino holding up monsoon

  1. Context: Monsoon may be delayed due to effects of El Nino
  2. El-Nino effect: This time the rain bearing winds doesn’t begin to draw across equator
  3. Therefore, Cross Equatorial flows haven’t developed
May, 11, 2016

What caused the monster El Nino in 2015?

  1. Context: New study gives the reason for EL Nino 2015
  2. Reason: Presence of warm water current due to effect of El Nino of previous year (2014)
  3. El Nino: A warm ocean current which replaces cold Peru Current into warm current
  4. It gives rise to heavy precipitation in Peru coast while drought and less rainfall in eastern pacific region & affects monsoon badly
Apr, 13, 2016

It’s official: India set for an ‘above normal’ monsoon

  1. News: India’s official weather forecasting agency too has said the monsoon is likely to be “above normal” and likely to be 106% of the average of 89 cm
  2. Reason: Waning El Nino and Positive Indian Ocean Dipole is also likely to form during the middle of the monsoon season
  3. Distribution: The monsoon will be fairly well distributed but southeast India will get slightly less rain
  4. Some regions would see floods and that the chances of drought were only 1% this year
  5. Observation: In the last century, 7 out of 10 years that followed an El Nino saw normal or above normal monsoon rains in India
  6. Fact: The years 2014 and 2015 were among the strongest El Nino years in meteorological history
Apr, 01, 2016

India to see a hotter-than-normal summer this year

  1. News: IMD has predicted that the above-normal heat wave conditions are very likely over central and northwest India during the summer
  2. The strong El Nino conditions in the Pacific are now on the decline
  3. For this season, IMD will provide extended range forecasts of heat wave conditions over the country every five days for the next 15 days
  4. Fact: 2015 was the third hottest year since 1901 and it was the third warmest year ever recorded since 1901
Mar, 19, 2016

Experts unsure if El Nino will fade away

  1. News: Meteorologists expect the monsoon in 2016 to be normal but are unclear if El Nino will completely fade away during the crucial monsoon months
  2. About: El Nino refers to an anomalous heating up of the waters in the central-eastern regions of the equatorial Pacific
  3. This implies a consistent, average rise in temperature of 0.5 degree Celsius above normal
  4. Relevance: Historically that translates to the monsoon drying up over India 6 in 10 years
  5. About La Nina: when waters in the same regions dip at least 0.5 degree Celsius and generally considered favourable for the monsoon, is only expected to set in after Sept
  6. Relevance: 2015 was only the fourth time in a 100-yr span that El Nino-like conditions raged on for 2 consecutive yrs
Feb, 20, 2016

El-Nino is receding

  1. Context: World Meteorological Organization (WMO) said El Niño has passed its peak and is in retreat
  2. Relief: Should bring relief for policy planners in India after two consecutive years of drought
  3. One of the most powerful: We have just witnessed one of the most powerful ever El Niño events
  4. Effects: Caused extreme weather in countries on all continents and helped fuel record global heat in 2015
  5. But not a time to celebrate: In meteorological terms El Niño is now in decline but we cannot lower our guard as it is still quite strong
  6. Future impact: in humanitarian and economic terms, its impacts will continue for many months to come
  7. Effect on India: A normal monsoon would help improve India’s macroeconomic prospects and boost rural demand
  8. Rural distress: A challenge for India is rural distress, triggered by a combination of consecutive droughts and a collapse of global commodity prices
Dec, 07, 2015

Freak weather whipped up a perfect storm

The highest daily rainfall in a century, a hottest-ever Indian Ocean, a strongest-ever El Niño.

  1. Freak weather conditions all came together on one single day to swamp Chennai with the heaviest rainfall in a century and it could all happen again.
  2. The World Meteorological Organisation(WMO) has been producing regular updates on the scale of this year’s El Niño.
  3. It’s expected, impact was a significant contributor to the India Meteorological Department’s forecast of a deficient south-west monsoon, a forecast that was spot on.
  4. El Niño affects whole season and is not responsible for individual episodes of intense rain.
Jun, 25, 2015

El Nino may have only a minor impact

  1. Contrary to an 8% average decline in agri output in previous El Nino years, this projected El Nino year will reduce output only by ~4.5%.
  2. Cotton will not be much impacted because of an increase in area under cultivation and long sowing periods.
  3. Majority of sugarcane is grown in irrigated areas which insulate it from El Nino effect.
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