The weather bureau has issued a heavy rainfall warning for the city on Friday.The India Meteorological Department (IMD) alerted coastal states about a weather system (depression) over coastal Odisha.Officials said the entire Konkan coast is expected to record an increase in rainfall intensity from Thursday onwards. Apart from Mumbai, heavy rain has been forecasted for Palghar and Thane on Friday and heavy to very heavy rain for Raigad, Ratnagiri and Sindhudurg for Thursday.“The low pressure area over the Bay of Bengal has now intensified into a weather depression. The system will pull moisture from the Arabian Sea. As this depression moves northwestwards over the east coast, it will intensify monsoon activity along the Konkan coast and interior Maharashtra,” said KS Hosalikar, deputy director general, western region, IMD. Meanwhile, light showers were recorded in Mumbai on Wednesday with 1mm rain in the suburbs and negligible rain in south Mumbai. The day and night temperatures in south Mumbai were close to normal but the day temperature in the suburbs was almost a degree Celsius below normal and the night temperature was almost 3 degrees Celsius below normal at Santacruz, at 22.2 degrees Celsius.