Today in weather history SPECIAL

Thomas Loades

December 24 • 1971 — now a largely forgotten event due to the storm described below, this was Australia's first devaststing christmas cyclone. Here, tropical cyclone Althea was moving SSE past the Queensland coast; it never made landfall, but on this day made its closest approach to the coast — where it struck Townsville, one of the state's larger coastal cities. The storm was about a strong Category 3 in strength, with winds of 120–130 mph, and a storm surge about 14 feet high (which had minimal impact to the town, as it was low tide, but badly damaged the naval base on the shoreline). Several hundred homes were damaged in the town, the small offshore Magnetic Island suffered damage to 90% of its structures, and 3 died. [Broken External Image]: Damage in Townsville from Cyclone Althea

December 24–5 • 1974 — in what is probably Australia's worst natural disaster, tropical cyclone Tracy made landfall on the NW coast of the Northern Territory overnight, striking the capital, Darwin, at peak intensity (category 5). There were three factors that proved most dangerous in this situation:
•To cope with the intense heat and humidity of Darwin's tropical climate, most houses were built with thin fibro walls, sheet-metal roofing, put up on stilts, and had glass-louver windows. There was no building code as to any secure construction techniques against cyclones.
•On December 3, tropical cyclone Selma was forecast to strike Darwin, but swung away at the last minute. People expected Tracy to do the same — in fact, for the first three-and-a-half days of its life, it moved SW, away from the city.
•And, hey, it's christmas! There're parties to go to, dinners to plan, presents to wrap! Who's got time to worry about a cyclone that probably isn't gonna hit, anyway?

On the afternoon of the 24th, though, Tracy made a 90° turn . . . right toward Darwin. At that time, she began rapidly intensifying.

By midnight, the winds were gale-force, and midnight mass at the church had to be called off because the roof was leaking, the candles kept going out, and the noise of the wind was starting to drown out voices.

At 0130 Australian Central Daylight Time, debris was starting to fill the air as the flimsy houses were starting to disintegrate.

At 0230, the anemometer at Darwin airport was deactivated by flying debris. Its last recorded wind gust was 135 mph. It has been esitmated that winds ultimately reached 160–185 mph. We also don't know how low the pressure in the storm went, because the needle fell off the barogram paper as the eye passed over at 0400. Its low was 28.06 inches (950 mb), but it probably went lower than that.

By dawn, the storm had passed, and the survivors emerged to find 90% of the city in utter ruins. 65 people died: 49 on land, and 16 at sea. Almost the entire population of the town was evacuated in the next week to allow for reconstruction efforts to begin. The town was largely restored — with improved building codes — by the late 1970s, and continues to increase in size today. It has not suffered a direct hit from a cyclone since.

8ad296eb4ace1c1c548e27152c62089f.jpgA typical Darwin house, pre-Tracy
[Broken External Image]: small view of damage to Darwin's suburbs from Tracy. Many houses were simply swept off their platforms, and yet people managed to survive under whatever was left (e.g. the closets on the platform to the right). Note what appears to be a girder lying across the sidewalk at center-left — this is, in fact, one of Darwin's steel power poles, bent at a right angle to the ground. A cluster of twisted poles are fixed in concrete out the front of Darwin's main library, as a memorial.