Tropical Cyclone Grant has been downgraded to a tropical low, however it is still bringing flooding rain and strong winds. The heaviest falls in the 24 hours to 9am were about exposed coastal parts of the Roper-McArthur district. Centre Island picked up 146mm to 9am, the highest December daily total in at least 42 years. Nearby Bing Bong gained a hefty 112mm in the gauge. Winds have also been strong at times about the Roper-McArthur and Arnhem districts, gusting to 78km/h at Cape Wessel just before midday on Wednesday. A Cyclone Watch has been declared for a developing tropical low for coastal areas from Thursday Island to Gilbert River Mouth in Queensland. The Cyclone Watch from Nhulunbuy to Port Roper, including Groote Eylandt in the Northern Territory has now been cancelled. At 9:30am CST on Wednesday the tropical low was estimated to be 140km west of Alyangula (northeastern NT Top End) and moving slowly east at 7km/h. The system is expected to move into the Gulf of Carpentaria later on Wednesday or overnight. As the tropical low moves over water it is likely to intensify, because cyclones are fueled by rising warm moist air i.e. over tropical waters. Current forecast maps indicate that the system will be upgraded to a category 1 cyclone on Friday morning, just before it reaches the Cape York Peninsula. Heavy rain is expected to cause flooding of low lying areas over the eastern Arnhem and Roper-McArthur districts of the NT today and Thursday. Heavy rain potentially leading to flooding is expected over the QLD Cape York Peninsula and northern parts of the Gulf Country on Thursday and Friday. Tides will be higher than normal between Milingimbi and Groote Eylandt in the Northern Territory and also between Thursday Island and Mornington Island in Queensland. Large waves may produce minor flooding along the foreshore. For the latest updates be sure to check weatherzone.com.au