GRACE

History

Tropical Cyclone Grace is remembered less for its brief life as a named system than for the damaging weather it produced beforehand. A multi-centred tropical low took shape close to the north Queensland coast near Cooktown as early as 20 March 2004, embedded in a vigorous monsoon trough that extended across the northern Coral Sea and Cape York Peninsula towards New Caledonia. The system initially looked subtropical in character, but over the following days the northernmost of its circulations became dominant and drifted eastward, positioning itself southeast of the ridge to its north. At 1820 UTC on 21 March it was named Grace, becoming the second cyclone named by Brisbane that season.

Grace tracked steadily towards the southeast at 15 to 20 knots, a motion it held for the rest of its existence. It reached its greatest strength early on 22 March (0000 UTC) near 20.3°S 155.9°E, with a central pressure of 985 hPa and maximum sustained winds of 50 knots (93 km/h), holding that intensity for roughly six hours. Interaction with a surface ridge to the south then squeezed the wind field into an increasingly lopsided pattern, and the cyclone began extratropical transition. Its upper-level structure collapsed quickly, and Grace was no longer classified as a tropical cyclone from 1800 UTC on 23 March, when it lay about 740 km east-northeast of Sandy Cape. The remnant low wandered east and east-northeast, spreading a very broad area of gales across the Tasman Sea to its south.

The heaviest rain fell over the far north Queensland coast, with Topaz recording 759 mm over three days, including 372 mm in 24 hours. Low Isle measured mainland gusts of 93 km/h, while Cape Moreton recorded 100 km/h. Flooding and road and property damage were widespread between Cooktown and Cairns, and wind and wave action pushed tides above the year's highest levels, particularly at Cooktown. All major routes into Cairns were cut, and a landslide destroyed part of the Captain Cook Highway, closing the Cairns–Port Douglas link for days. Whitfield range residents were evacuated. Damage in the Cairns region was estimated at US$20 million, with no lives lost. New Caledonia also saw strong winds, heavy rain and flooding.

Sources: Bureau of Meteorology report Wikipedia