On the 22nd of January a tropical low was identified approximately 390 kilometres north of Kalumburu. The low gradually strengthened as it moved towards the southwest on a track that was roughly parallel to the northwest Kimberley coast, producing heavy rainfall as it did so. In the 24-hour period to 9am on the 23rd, 132mm was recorded at Troughton Island, and 65mm was recorded at Kalumburu in the 24 hours up to 9am on the 24th.
|Following further intensification, the low became Tropical Cyclone Riley at 5am AWST on the 24th when it was located about 180 kilometres northwest of Broome. Rowley Shoals (about 350 kilometres to the west of Broome) reported gale force winds for periods late on the 24th and during the 25th with a peak gust of 94 kilometres per hour at 0728 AWST on the 25th. |
|Riley then moved generally towards the west and strengthened into a category 2 tropical cyclone at 2am AWST on the 25th, when it was located about 370 kilometres west northwest of Broome. Riley briefly reached category 3 intensity at 0800 AWST on the 26th, when it was located 390 kilometres north northwest of Port Hedland. It also attained category 3 intensity between 0800 AWST on the 27th and 1400 AWST on the 28th. |
|For a period on the 26th, Riley tracked more towards the southwest before resuming a general west-southwest track. It weakened into a category 1 tropical cyclone at 5am AWST on the 29th, well to the northwest of Exmouth and then below tropical cyclone intensity at 8am AWST on the 30th, when it was approximately 1150 kilometres west of Exmouth. |
|Tropical Cyclone Advices were issued for the northwest Kimberley coast between Kuri Bay and Beagle Bay and then for the Pilbara coast between Whim Creek and Exmouth.
Riley was the third tropical cyclone in the Australian region and the first off the northwest Western Australian coast for the 2018/19 season.
|**All information relating to intensity and track is preliminary information based on operational estimates and subject to change following post analysis.**|