The tropical low that would become tropical cyclone Nathan was first identified and tracked on the morning of Monday 9 March, 2015 in the northern Coral Sea, to the near south of Papua New Guinea. During the next 36 hours the low drifted towards the west-southwest while slowly intensifying, and was named as category 1 cyclone Nathan on the evening of Tuesday 10 March. The cyclone continued to move west-southwest towards Cape York Peninsula while developing further, reaching category 2 after another 12 hours on the morning of Wednesday 11 March. Following this, Nathan stalled and became slow moving off the Cape York Peninsula coast near Cape Grenville for roughly two days at category 2 strength. During this time, Lizard Island experienced damaging wind gusts but there was little impact on the mainland.
|Nathan was then steered to the east away from the coast for the next two days, before becoming slow moving as steering patterns again became confused. Nathan drifted very slowly south for two more days, all this time fluctuating between category 1 and category 2 in intensity. Finally Nathan was again steered westwards towards the Cape York Peninsula coast and intensified, reaching category 3 strength on the morning of Thursday 19 March, and category 4 strength in the last hours before it made landfall at about 4am on Friday 20 March on the east Cape York Peninsula coast near Cape Flattery, not far from where it had stalled a week earlier. The location where Nathan made landfall was unpopulated so impacts were fairly low. Cape Flattery automatic weather station recorded wind gusts to approximately 170 km/h. Some wind damage occurred in Cooktown to the south. Following landfall, Nathan tracked westwards across Cape York, emerging briefly over water again in Princess Charlotte Bay early on Friday afternoon. This contributed to slowing Nathan's weakening, and it was able to maintain marginal category 1 cyclone intensity all the way across the Cape before it entered the waters of the Gulf of Carpentaria early on the morning of Saturday 21 March.|
|Tropical cyclone Nathan moved steadily westward across the Gulf of Carpentaria on Saturday 21 March and turned northwest towards the Arnhem coast of the Northern Territory early on Sunday 22 March. Nathan intensified in a favourable environment while over warm Gulf waters and reached high category 2 intensity shortly before crossing the Arnhem coast about 40 kilometres south of Nhulunbuy around 9 am on Sunday. Although wind gusts were estimated to be around 155 km/h near the centre, the town of Nhulunbuy remained outside of the zone of destructive winds and experienced around 3 hours of sustained gales. The highest gust recorded at Gove Airport was 98 km/h at 9:34 am on Sunday. Minor coastal inundation occurred at Nhulunbuy where several yachts were damaged when they broke their moorings.|
|Nathan maintained category 2 intensity as it emerged from the Gove Peninsula near Arnhem Bay and passed over Elcho Island around 7 pm on Sunday 22 March. Nathan continued westwards over the southern Arafura Sea just north of the Top End coast during Monday, before weakening rapidly as it turned southwest on Monday evening. Nathan made its third and final landfall at category 1 intensity in a remote area between Maningrida and Goulburn Island around 6:30 am Tuesday 24 March. Nathan then weakened below tropical cyclone intensity by 2 pm Tuesday as it tracked inland close to the towns of Gunbalunya and Jabiru. Fortunately the destructive core of the cyclone skirted around the north coast communities of Galiwin'ku, Ramingining and Milingimbi, which were seriously damaged by Severe Tropical Cyclone Lam in February. The strongest gust recorded at Ngayawili AWS near Galiwin'ku was 107 km/h at 7 pm on Sunday 22 March and 3 hours of gale-force winds were observed. Only minor additional damage was reported from the affected communities during Nathan's passage.|
|Tropical Cyclone Nathan and its remnant tropical depression brought heavy rainfall and flooding to many parts of the Northern Territory's Top End. The highest 24 hour rainfall totals included 208 mm at Alcan Mine on the Gove Peninsula, 261 mm at Fanny Creek and 215 mm at Dorisvale in the Katherine River catchment and 208 mm at Snowdrop Creek in the Waterhouse River catchment. Flood Warnings were issued for both of these rivers.|
|Nathan was the second cyclone in both the Queensland and Northern Territory areas of responsibility this season, preceded by Marcia in Queensland and Lam in the Northern Territory.|