Tropical Cyclone Iggy

23 January - 3 February 2012


A deep and well organised monsoon trough combined with an active phase of the Madden-Julian Oscillation (MJO) to produce a tropical low pressure system near 15°S 116°E late on 23 January. Initially the tropical low moved west before turning south southeast and intensifying into a tropical cyclone on 25 January. During the period 25 - 30 January Iggy was under a weak steering flow and it drifted slowly south, then east and then west, well offshore from the Western Australian coastline. Iggy was also under the influence of easterly wind shear and satellite imagery showed an exposed low-level centre with deep convection displaced over the western half of the tropical cyclone. During 30 and 31 January Iggy turned to the south and accelerated. Iggy became symmetric and reached a 10-minute mean wind peak intensity of 60 knots (kn) (111 kilometres per hour (km/h)) at 1200 UTC 31 January well to the west of the upper west coast of Western Australia.

The tropical cyclone continued to track south and weakened quickly as it moved over cooler Sea Surface Temperatures (SSTs) and increased wind shear. During 1 February Iggy turned southeast toward the Western Australian coastline. Iggy weakened below tropical cyclone strength by 0600 UTC 2 February. The remnant low pressure system caused near gale force winds along the Central West coast and heavy rainfall between Perth and Lancelin.

A pronounced tidal surge was recorded at most towns from Onslow to Perth as Iggy moved south along the west coast. The peak was 80 centimetres (cm) recorded at Geraldton and 70 cm at Fremantle on 2 February with no apparent damage reported from any locations.

For more information see the TC Iggy Report (pdf).

Track and Intensity NT

Best Track of Tropical Cyclone Iggy