Heat Wave

Context:

The Konkan region, including Mumbai, has been experiencing sweltering heat in the recent days, with the maximum temperatures touching the 40 degrees mark.

Relevance:

GS  III- Environment (Climate change)

Dimensions of the Article:

1. About Heat Wave
2. Health Impacts
3. Why is Konkan experiencing heatwave conditions?
4. What is the forecast?

About Heat Wave

• A heat wave is a period of abnormally high temperatures, more than the normal maximum temperature that occurs during the summer season in the North-Western and South Central parts of India.
• Heat waves typically occur between March and June, and in some rare cases even extend till July.
• Higher daily peak temperatures and longer, more intense heat waves are becoming increasingly frequent globally due to climate change.

Criteria for Heat Waves

• The heat wave is considered when the maximum temperature of a station reaches at least 40°C for Plains and at least 30°C for Hilly regions.
• If the normal maximum temperature of a station is less than or equal to 40°C, then an increase of 5°C to 6°C from the normal temperature is considered to be heat wave condition.
• Further, an increase of 7°C or more from the normal temperature is considered as severe heat wave condition.
• If the normal maximum temperature of a station is more than 40°C, then an increase of 4°C to 5°C from the normal temperature is considered to be heat wave condition. Further, an increase of 6°C or more is considered as severe heat wave condition.
• Additionally, if the actual maximum temperature remains 45°C or more irrespective of normal maximum temperature, a heat wave is declared.

Health Impacts

• The health impacts of Heat Waves typically involve dehydration, heat cramps, heat exhaustion and/or heat stroke.
• It also causes heat cramps, fatigue, weakness, dizziness, headache, nausea, vomiting, muscle cramps and sweating.
• The extreme temperatures and resultant atmospheric conditions adversely affect people living in these regions as they cause physiological stress, sometimes resulting in death.

Why is Konkan experiencing heatwave conditions?

• The ongoing heatwave in Konkan, including Mumbai, is because it is under the direct influence of the prevailing heatwave in the adjacent Saurashtra-Kutch regions of Gujarat.
• The hot and dry winds from northwest India are reaching parts of Konkan.
• In addition, the slow movement of sea breeze along the Maharashtra coast and the overall clear sky conditions have together resulted in such hot conditions

What is the forecast?

• The IMD has warned that heat wave to severe heat wave conditions will prevail over Kutch – Saurashtra
• As the hot and dry winds continue to blow from these areas of Gujarat over Konkan, especially north Konkan districts including Mumbai, the maximum temperatures will remain around 38 degrees Celsius at least for the next two days.
• The IMD has issued an ‘orange’ alert, warning that severe heat wave is likely to prevail over Mumbai, Thane, Raigad, Ratnagiri, Palghar, Ratnagiri and Sindhudurg districts, and a ‘yellow’ alert over these coastal districts on Wednesday.