Many parts of Tamil Nadu are likely to be gripped by scorching heat till April 12. The Regional Meteorological Centre (RMC) has forecast an increase in maximum temperature by two to three degrees Celsius till Sunday.

With the summer heat gradually rising in the State, the RMC has issued a heat index advisory , particularly coastal pockets, on Thursday. RMC officials noted that the trough prevailing over Tamil Nadu would lead to moisture incursion and increase humidity. . The combination of humid air and high temperatures would influence hot weather and discomfort in places like Chennai.

V.R. Durai, Director, Area Cyclone Warning Centre, RMC, said coastal places may experience uncomfortable and hot weather as southeasterly winds prevailing in the morning hours bring moisture into the land and add to the humidity level.

The day temperature in Chennai may touch 36-37 degrees Celsius on Thursday. While some places like Chennai have chances of thundershowers on Thursday owing to convective activity, it would provide only a temporary relief from the searing heat.

Some parts of Western Ghats and adjoining districts are likely to receive moderate rainfall till April 14. A few other parts of the State may also have chances of light rainfall till the weekend.

Noting that the global weather condition has transitioned from La-Nina to a neutral phase, officials said the Pacific Ocean is gradually warming, signalling a shift in ocean-atmosphere dynamics. Mr. Durai said the transition is expected to enhance surface heating, and the coastal region could experience higher humidity and discomfort. Tamil Nadu is likely to experience above-normal temperatures and intense summer conditions.

Many interior parts of the State sizzled on Wednesday as well, with Karur Paramathi recording the hottest temperature of 41 degree Celsius followed by Erode with 40 degree Celsius. Chennai Meenambakkam recorded 37.5 degree Celsius.