What is the issue?
- In recent period, certain states of India witnessed a worrying number of lightning related deaths.
- It is essential in this backdrop to understand the association between lightning and monsoon, if any.
How has rainfall distribution been?
- It is roughly a fortnight since the start of the South-West monsoon.
- India has recorded nearly 55 mm of rain.
- This is 16% more than what is usual for this time of the year.
- The bulk of it has been over south and central India.
- The north-eastern States has so far registered a 24% deficit.
What is IMD's prediction?
- After an early onset and quick advance, the monsoon has stalled and will remain so for at least a week.
- However, several parts of north-eastern India are expected to receive substantial rain.
- Because the southern branch of the monsoon has stalled.
- It is causing heavy rain in Goa, coastal Karnataka and Kerala.
- These have seen 44 cm, nearly 49% more than what it gets in the first fortnight of June.
- This has led to widespread havoc.
How has lightning activity been?
- This year saw nearly 300 deaths due to lightning in UP, Bihar, Jharkhand and WB.
- This was however in May which is not a monsoon month.
- Because of unusual convective activity, Andhra Pradesh in April recorded nearly 36,000 lightning strikes in a single day.
- Typically that is what the State suffers in an entire pre-monsoon month.
- Despite all that lightning, no more than 10 deaths were reported.
- Therefore, even pre-monsoon rain can contribute to massive cloud buildups and trigger widespread lightning strikes.
- Thus, there is no one-to-one link between the strength of the monsoon in one year and lightning deaths.
- 2,000-2,500 deaths occurring due to lightning annually is ‘normal,’ as per the NCRB figures.
- It is thus early to understand if this year has seen an unusual spike.
Why is lightning a serious concern?
- Lightning is the leading cause of accidental deaths in India attributable to the forces of nature.
- Nearly 25% of accidental deaths attributable to natural causes were due to lightning.
- That lightning strikes disproportionately affect the poor is also a fact.
- So poorly built houses, staying out in the open, being in places that aren’t properly electrically insulated, etc are some driving factors.
- The mere fact of working in open fields substantially increases the risk of death from lightning.
What is the challenge in early warning?
- Lightning and thunderstorms are an extremely ‘local’ phenomenon.
- The impact spreads no more than a few kilometres.
- Also they tend to occur rather suddenly and are therefore beyond the range of the weather radars.
- However, it is possible for the meteorological department to warn of the likelihood of thunderstorms and lightning.
- This can be given for a district or a city, about a day in advance.
- But street-level or area-wise accuracy is a tough challenge.
What could be done?
- Build-up of clouds is known to be a factor which can help predicting.
- However, much more improved weather modelling is required to give accurate warnings.
- State- and district-level disaster management agencies routinely issue advisories.
- It includes asking people to refrain from using mobile phones or handling electrical equipment plugged to sockets.
Source: The Hindu
