DELILAH

History

Tropical Cyclone Delilah developed at the very start of January 1989 from a hybrid system over the north-western Coral Sea, where an upper-level cold-core trough interacted with a low-level monsoonal depression in the final days of December 1988. The precursor low displayed subtropical characteristics, including a broad wind field, before consolidating into a named tropical cyclone near 18°S on 1 January.

Steered south-south-eastwards between an upper trough over eastern Australia and a ridge of high pressure to the east, Delilah tracked roughly parallel to the southern Queensland coastline, remaining around 300 km offshore, before crossing into the South Pacific basin and heading towards New Caledonia and the Loyalty Islands. The system reached its peak late on 2 January, with some analyses rating it a Category 3 severe tropical cyclone with a central pressure near 970 hPa and 10-minute winds of 120–130 km/h, while the Fiji Meteorological Service and the Joint Typhoon Warning Center assessed peak sustained winds nearer 110 km/h as the cyclone passed within 30–50 km of the north-eastern coast of New Caledonia. Delilah made no landfall.

From 3 January, increasing vertical wind shear, strengthening upper westerlies and cooler waters caused the cyclone to weaken and begin extratropical transition, which was complete by 4 January. The remnant mid-latitude depression then accelerated south across the Tasman Sea, passing close to northern New Zealand on 7 January before merging with a cold front the following day.

New Caledonia bore the brunt of the storm on 2–3 January. Gusts of 166 km/h were measured at Koumac and 157 km/h at Touho, while 330 mm of rain fell at both Pouébo and Ponérihouen, triggering landslides, river flooding and damage to crops, power supplies and buildings. Two people died in the French territory. Along the south-east Queensland and northern New South Wales coasts, Delilah's broad circulation produced gales, heavy seas and significant beach erosion, and its remnants brought heavy rain, gales and localised flooding to New Zealand's North Island.

Sources: Bureau of Meteorology report Wikipedia