South Interior Karnataka and Tamil Nadu are likely to witness thunderstorm and lightning accompanied with gusty winds (40-50 kmph) on May 26, 2019, the India Meteorological Department said on Saturday.
The weather forecasting agency also predicted that heavy rainfall is likely over Assam, Meghalaya, Nagaland, Manipur, Mizoram and Tripura.
Heatwave conditions in some parts are very likely over Vidarbha and northeast Madhya Pradesh and in isolated pockets over Telangana, Madhya Maharashtra, Marathwada, Chhattisgarh, Odisha, Jharkhand and East Uttar Pradesh.
Besides, strong winds speed reaching 35-45 kmph are very likely over the northeast Arabian Sea off north Gujarat Coast.
The IMD has adviced fishermen not to venture into this area for the next couple of days.
Earlier, private weather forecaster Skymet predicted that Monsoon is likely to arrive in Kerala on June 4, three days after its normal onset date, marking the official commencement of the rainy season in the country.
The normal onset date for monsoon over Kerala is June 1.
Skymet said monsoon will be "below normal" in the country with a Long Period Average (LPA) of 93 percent and an error margin of five percent.
"Arrival of monsoon over Andaman and Nicobar Islands will be on May 22, with an error margin of plus/minus 2 days. Southwest Monsoon 2019 is likely to make onset over Kerala on June 4, with an error margin of plus/minus 2 days. It seems that initial advancement of monsoon over peninsular India is going to be slow," Skymet CEO Jatin Singh said.
"All the four regions are going to witness lesser than normal rainfall, this season. Rainfall in East and Northeast India and central parts will be poorer than Northwest India and South Peninsula," Singh said.
According to Skymet, there are 55 per cent chances of a below-normal rainfall, which will have an influence of El Nino, a phenomenon linked to the heating of Pacific waters.
East and Northeast India will get 92 per cent of the LPA which falls under the below normal category. The risk remains high for Bihar, Jharkhand and West Bengal, while it will be marginal for Northeast India, Skymet said.