Behind unseasonal rain & lightning strikes in Gujarat

Subject: Geography

Section: Physical geography

Context:

Unseasonal heavy rainfall accompanied by thunderstorms, hailstorms and lightning strikes claimed 27 lives in Gujarat.

Details:

The disaster management system is designed more for earthquakes and heavy rainfall and not for lightning, which annually contributes to many deaths in India.

What explains the weather events?

The rain and the lightning have been attributed to the three weather systems- cyclonic circulation over the Northern Arabian Sea and adjoining Saurashtra and Kutch, Western Disturbances, and an easterly trough.
Western disturbances are storms that originate over the Mediterranean Sea region and may bring rainfall to northwestern India in the winter.
Easterly winds flow from the east in the equatorial region throughout the year.

Why the lightning strikes?

There are two reasons for lightning strikes:
- Whenever there is an interaction between any system and Western Disturbances, it leads to lightning.
- The first spell of activity after a long dry period leads to convective activity, which results in lightning.
The thunderstorm can also be explained by the presence of more moisture interacting with the Western Disturbances this time.
This time, the equatorial region, particularly the Intertropical Convergence Zone (ITCZ, located slightly north of the Equator) is also very active.

Gujarat State Disaster Management Authority (GSDMA):

Set up in 2001, after the Bhuj earthquake.
It was to act as a nodal agency to plan and implement pre-disaster preparedness and migration activities.
One of the objectives of GSDMA, as part of long-term disaster preparedness, is to prepare programmes and plans to mitigate losses on account of disasters as a strategy.
The authority is working on an early warning system for cyclones.