IMD's Annual Summer Forecast

Why in news?

India Meteorological Department (IMD) has recently released its annual summer forecast.

What are the key aspects?

Summer - ‘Normal’ temperatures refer to the mean temperatures during a particular period (months) between 1981 and 2010.
IMD has forecasted a “warmer” than normal summer months from March-May.
Heat Waves - The IMD’s climate summary in January said that 2017 was the “fourth warmest year on record since 1901”.
Several parts of India, from Palakkad in Kerala to Mumbai, reported heat wave conditions.
They recorded day time temperatures greater than 35°C.
Increasing trends in the frequency and duration of heat waves over the country is also indicated.
This is attributed to increasing trends in the greenhouse gases emission.
The warming of the sea surface temperatures over the equatorial Indian and Pacific oceans is also a reason.
Regions - A harsh summer is awaiting certain states, with mean seasonal temperature-spikes likely to be greater than 1 °C.
These are J&K, Punjab, HP, west and east Rajasthan, Uttarakhand, west and east UP, west and east MP, Vidarbha, Gujarat and Arunachal Pradesh.
Certain parts would witness temperature rise between 0.5°C and 1°C from their historical normal.
These include Tamil Nadu, south interior Karnataka and Rayalaseema.

La Nina - La Nina is a weather condition that generally brings heavy rains to India.
Currently, the sea surface temperature conditions over equatorial Pacific suggest moderate La Nina conditions.
The IMD forecast indicates that La Nina conditions are likely to be moderate till spring (May-end).
They are likely to start weakening after spring.
But even if La Nina weakens, it is sure that El Nino (which negatively effects monsoon) will not immediately develop.
Given these, the prospects of a normal monsoon are more.
However forecasts before spring are prone to error, with better accuracy after May.

Why is the forecast significant?

A scientific estimate of annual mortality attributable to heat waves between 2010 and 2015 ranges between 1,300 and 2,500.
For many States, the summer of 2018 may pose a public health challenge.
Even a marginal rise above the normal may lead to enormous heat stress for millions of Indians, given the deprived conditions of life.
A heat event can lead to fatal heat stroke in some, and exhaustion, cramps and fainting in many.
Moreover, there are distinct groups at particular risk for health-related problems during a heat wave.
These include senior citizens and people with pre-existing disease, mental illness or disability.

What does it call for?

The IMD's forecast is a timely alert for State authorities to review their summer preparedness.
Interventions - States must facilitate for community-level interventions.
This is to deal with heat stress and particularly to help the vulnerable groups.
All stakeholders, including the health-care system, should be prepared to deal with the phenomenon.
Alerts - The World Health Organisation recommends that countries adopt heat-health warning systems.
This includes daily alerts on weather conditions.
This could ensure that people are in a position to deal with adverse weather, starting with reduction of exposure.
Water stress- Water stress is a common and often chronic feature in many States.
Arrangements should be made by the State authorities to meet possible water scarcity.
GHG - The average temperature caused by climate change and the frequency and intensity of extreme weather events are perceivably linked.
Thus, taking a long-term view, India has to pursue mitigation of greenhouse gases.

Source: The Hindu

Quick Fact

La Nina

La Nina is associated with the cooling of the eastern equatorial Pacific Ocean.
It favourably impacts the four-month long (June to September) south-west monsoon in India.
This is particularly critical to the rain-fed farming season which begins in June.