With reference to quot heat wave condition quot consider the following statements 1 A heat wave is a...........

Geography World climates

With reference to "heat wave condition" consider the following statements?

1. A heat wave is a prolonged period of excessive heat, often combined with excessive humidity.

2. In India, heat wave is declared only after the temperature of a station reaches at least 40°C in plains and hilly areas.

Select the correct answer using the codes given below

1 only

2 only

Both 1 and 2

Neither 1 Nor 2

Heat waves form when high pressure aloft (from 10,000–25,000 feet (3,000-7,600 metres)) strengthens and remains over a region for several days up to several weeks. This is common in summer (in both Northern and Southern Hemispheres) as the jet stream 'follows the sun'. On the equator side of the jet stream, in the middle layers of the atmosphere, is the high pressure area.
The India Meteorological Department (IMD) has defined heat wave under two categories. The first category includes places where the normal maximum temperature is more than 40°C. In such regions if the day temperature exceeds by 3 to 4°C above the normal, it is said to be affected by a heat wave. Similarly, when the day temperature is 5°C or more than the normal, severe heat wave condition persists.
The second category considers the regions where the normal maximum temperature is 40°C or less. In these areas, if the day temperature is 5-6°C above the normal, then the place is said to be affected by a moderate heat wave. A severe heat wave condition exists when the day temperature exceeds the normal maximum temperature over the place, by 6°C.
Heat Wave need not be considered till maximum temperature of a station reaches atleast 40°C for plains and at least 30°C for hilly regions.