New Delhi, Nov 18 : Cyclonic storm 'Midhili' on Saturday weakened into a low pressure area over north Tripura and neighbourhood, the India Meteorological Department (IMD) said. The weather forecast agency further said that Midhli is likely to continue to move further north eastwards and become less marked during the next six hours. In its bulletin, the IMD also predicted light to moderate rainfall at some places likely over Mizoram and Tripura. "Light to moderate rainfall is also expected at some places with isolated heavy rainfall very likely to continue over Tamil Nadu and Kerala during Saturday and November 20, on coastal Andhra Pradesh during November 21 and over Tamil Nadu on November 22 also," said the IMD. The IMD further said that isolated thunderstorm activity is very likely to occur over these above regions during November 18 to 22. It also predicted isolated heavy rainfall very likely over Andaman and Nicobar Islands on Saturday. While issuing the dense fog warning, the IMD said that dense fog is very likely in isolated pockets of east and south Assam, Meghalaya, Nagaland, Manipur, Mizoram and Tripura during Saturday and Sunday. /IANS