In the first part of the question, the requirement is simple: Describe what is convective storms and what are its basic characteristics. In the second part, you have to describe how convective storms are unlike other climatic phenomenons (Because of unpredictability and nature) and how it affects things on Earth. Discuss the effects of convective storms on India too in this part.
While discussing the characters of the convective storms, try to use the diagram to describe how these storms are formed. Also another key aspect of this topic is try to use easy language and do not use too much technical language while making examiner understand nature of convective storms.
Convective storms, also known as thunderstorms, are caused due to a process called convection where a parcel of moisture laden air rises from earth’s surface due to intense heating to the upper layers of the atmosphere. They are responsible for weather hazards such as lightning, heavy rain, hail, and tornadoes, sudden temperature changes and snow (in winter).
Characteristics of Convective Storms:
- Convective Storms are severe local storms.
- They are of short duration, occurring over a small area but are violent.
- Convective Storms are storms with thunder and lightning and typically also heavy rain or hail.
- Convective Storms mostly occur on ground where the temperature is high.
- They are less frequent on water bodies due to low temperature.
- Worldwide, there are an estimated 16 million thunderstorms or Convective Storms each year, and at any given moment, there are roughly 2,000 thunderstorms in progress.
- Convective Storms are caused by intense convection on moist hot days.
- If there is insufficient moisture, a thunderstorm can generate dust-storms.
- A Convective Storm is characterised by intense updraft of rising warm air, which causes the clouds to grow bigger and rise to greater height.
- This causes precipitation. Later, downdraft brings down to earth the cool air and the rain.
Why Convective Storms Are Atypical?
- Convective Storms bring lightning with themselves.
- Many hazardous weather events are associated with Convective Storms.
- Several thousand Convective Storms occur over India every year.
- Severe Convective Storms occur in large numbers and in their most violent form over India during the pre-monsoon months of April and May as well as during the month of June.
- But they are also associated with winter season when western disturbances bring Convective Storms to the Indian Subcontinent.
- Incidents of lightning have been showing an increasing trend over the last 20 years, especially near the foothills of the Himalayas.
- People are rarely hit directly by lightning. But such strikes are almost always fatal.
- The most common way in which people are struck by lightning are by ‘ground currents’.
- Predicting a Convective Storm over a very precise location is not possible. Nor is the exact time that it is likely to strike.
- Under the right conditions, rainfall from Convective Storms causes flash flooding, killing more people each year than hurricanes, tornadoes or lightning alone.
- Lightning is responsible for many fires around the world each year, and causes fatalities.
- Hail up to the size of cricket balls damages cars and windows, and kills livestock caught out in the open.
- Strong (up to more than 120 mph) straight-line winds associated with Convective Storms knock down trees, power lines and mobile homes.
- Crop losses worth millions are associated with convective storms occurring during winter season.