Low pressure area to develop over BoB; heat waves sear central India

The Meteorological Department has recently informed that along with Saurashtra and Kutch, there may be heat wave in some parts of Konkan. Along with this, heat wave predictions are also coming from some parts of Rajasthan, Karnataka and Gujarat.

About Heat Waves:

• Heat Wave is simply, a continuous spell of abnormally hot weather.
• Heat wave need not be considered till maximum temperature of a station reaches at least 40º C for Plains and at least 30º C for Hilly regions.

Criteria for declaring Heat Wave followed by IMD

Situation 1 - When normal maximum temperature of a station is less than or equal to 40º C. Declare Heat Wave if:

• Heat Wave Departure from normal is 5º C to 6º C
• Severe Heat Wave Departure from normal is 7º C or more

Situation 2 - When normal maximum temperature of a station is more than 40º C. Declare Heat Wave if:

• Heat Wave Departure from normal is 4º C to 5º C
• Severe Heat Wave Departure from normal is 6º C or more

Situation 3 - When actual maximum temperature remains 45ºC or more irrespective of normal maximum temperature, heat wave should be declared.

Present situation:

• Several parts of the country are recording heat waves and severe heat wave conditions.
• Maximum temperatures were around 39-41 C° over many parts of Gujarat and West Rajasthan
• 38- 40 C° over some parts of southeast Rajasthan, Vidarbha and Konkan and Goa. 
• Maximum temperatures were above normal by 3-6 C° at most places over Punjab and Uttarakhand; at many places over Jammu-Kashmir-Ladakh-Gilgit-Baltistan-Muzaffarabad; at a few places over Himachal Pradesh, West Rajasthan and Saurashtra and Kutch; at isolated places over East Rajasthan and Gujarat.
• Delhi recorded a maximum temperature of 34.7 degree C, 5 degrees above normal and minimum of 18.9 degree C, 3 degrees above normal.

Reason: The immediate reason for such high temperatures in these places is the south-easterly wind blowing towards central India from very warm regions like Tamil Nadu and Andhra Pradesh.

Recent Alerts:

• A low-pressure area is likely to form over the equatorial Indian Ocean and adjoining Southwest Bay of Bengal.
• There is a possibility that the low-pressure area intensifies further and becomes a cyclone in the coming days.
• Under the influence of the low-pressure area, scattered to widespread rainfall is very likely over Andaman & Nicobar Islands with isolated thunderstorm/ lightning.
• Isolated heavy rainfall is also likely over the region.
• Strong Winds (speed reaching 40-50 kmph gusting to 60 kmph) are likely to prevail over south Andaman Sea.
• The sea surface temperatures are warmer than normal along the region where the low-pressure area is likely to develop.
  • The SST is around 30 degree C according to the Cooperative Institute for Meteorological Satellite Studies.