Titlagarh in Odisha has recorded a maximum temperature of 48.5 deg Celsius during the 24 hours ending Monday morning as the heat wave continued unabated in East India.

An India Met Department forecast indicated that the ‘top heat’ will stay pinned to this region until April 29 with a likely extension to Bihar and East Uttar Pradesh during the period.

Cooler North-West



In contrast, North-West India will remain largely insulated from the searing heat thanks to western disturbances calling in one after the other and setting off thunderstorms and dust storms in the region.

Western disturbance represents a belt of lower pressure that circumnavigates the globe and periodically dips over Afghanistan-Pakistan-North-West India to impact seasonal weather.

Areas of low pressure during this time of the year here are associated with varying weather including rain, showers, high winds, hail, squall, thunder and lightning.

Thunderstorms/dust storms are other manifestations of this type of weather; they help bring down maximum temperatures by several notches.

But enabling conditions for proper monsoon onset and progress demand that North-West India too heat up without much delay.

‘Heat low’



In the monsoon scheme of things, it is here that the ‘heat low’ develops after the rising motion of air sets up the lowest point of atmospheric pressure in Rajasthan.

This will make for a perfect contrast with the relatively high pressure obtaining to the South-West of the country (around Kerala) from where monsoon winds can blow in towards the North of the country.

According to international forecasts, the heating of North-West India may begin in right earnest by the end of this week.

Extreme West Rajasthan is shown as heating up to a new high by May 3 even as the heat wave phenomenon will be confined to Odisha, Coastal Andhra Pradesh and Telangana.

It remains to be seen how long the ‘heat low’ can sustain given the frequent movement of western disturbances and development of thundery weather in and around Rajasthan.

Severe heat



The IMD has forecast heavy wave conditions at a few places over Odisha on Tuesday with severe heat wave at isolated places.

Heat wave conditions are also likely in the immediate neighbourhood i.e. Bihar, Jharkhand, Gangetic West Bengal, Telangana and Rayalaseema.

In contrast, dust storms/thunderstorms are likely to line up in Punjab, Haryana, Chandigarh, Delhi, West Uttar Pradesh, and Rajasthan to put a cap on the heating trend.

Thunderstorms accompanied by squall/hail are also likely at isolated places over Assam, Meghalaya, Nagaland, Manipur, Mizoram, and Tripura.

This will more or less be the pattern of weather panning out over the respective regions for another two to three days, the Met said.