RAW VISION: record flood levels in Grafton
Authorities expect flood levels in Grafton to reach record heights after the Bureau of Meteorology issued major flood warnings for Clarence Valley.PT0M46S http://www.canberratimes.com.au/action/externalEmbeddedPlayer?id=d-2di28 620 349 January 29, 2013
As towns and cities along Australia's eastern seaboard cope with flooding in the wake of ex-tropical cyclone Oswald, rainfall figures from the Bureau of Meteorology underscore the scale of the deluge.
Among major population centres, Gladstone appears to have copped the heaviest falls. The coastal Queensland city registered 819.8 millimetres of rain in the four days to Sunday, not far shy of its annual average rainfall of 883 millimetres.
The most exceptional feature of this storm is the extent of the extremes along a very long distance of coast
In fact, those four days exceeded the previous monthly record for the city of 768.7 millimetres, back in February 1911, according to Blair Trewin, a senior climatologist at the bureau.
Gladstone area's Awoonga Dam overflows. Photo: Gladstone Region Local Disaster
Gladstone collected more rain over the four days than it did during the whole of 2011 or 2012.
"The most exceptional feature of this storm is the extent of the extremes along a very long distance of coast," Dr Trewin said.
Other notable falls included Bundaberg – site of some of Queensland's worst flooding – which had 484 millimetres over the same four days, most of which fell in just two days.
The Burnett catchment behind Bundaberg saw an average of 204 millimetres of rain in the 24 hours to 9am on Sunday, smashing the previous record average of 124 millimetres, Dr Trewin said.
Rockhampton also gathered 545.4 millimetres in the four-day period to Sunday, including one day of 349 millimetres.
“That's the power of a tropical cyclone,” said Aaron Coutts-Smith, NSW climate services manager, noting the storm had been unusually slow-moving.
The one-day rainfall totals marked all-time records for the current observation sites which date from 1939 in Rockhampton and 1957 in Gladstone, while Bundaberg's tally was a record for January, Dr Trewin said.
Impressive peak daily rainfalls at other major coastal centres included 144.8 millimetres at Townsville, 112 millimetres at Cairns, 159.2 millimetres at Mackay, 145 millimetres at Brisbane and 128 millimetres at Coolangatta. A total such as Brisbane's occurred about once every five years, Dr Trewin said.
The Gold Coast hinterland and the NSW border ranges had some of the other exceptional falls.
Upper Springbrook, for instance, had 744 millimetres in 24 hours, and 1453 millimetres in four days.
Other significant departures from the historical norms include falls in the Burnett catchment region. Gayndah, in its upper reaches, received a peak daily total of 282.8 millimetres, far in excess of the previous record of 185.4 millimetres.
In NSW, Pine Ridge, near Tamworth, broke its January one-day rainfall record of 131 millimetres in the 24 hours to 9am on Tuesday.
Other notable falls included Wyee, near Lake Macquarie, which received 171.8 millimetres, its highest January tally in 113 years of records. Grafton's Olympic site also notched its highest January rainfall - 131 millimetres in the 24 hours to 9am on Monday.
Old Koreelah, inland from Byron Bay, collected 205 millimetres in its rain gauge in the 24 hours to 9am Monday - the highest daily rainfall measured in a century of records.
Initial numbers point to Crystal Creek on the northern Rous River as recording the state's highest rainfall total of 288 millimetres in the 24 hours to 9am on Tuesday.
Sydney's Observatory Hill recorded 95 millimetres for the period, the highest level since last March's severe rainstorms. In the Sydney region, the north shore's French's Forest and Castle Cove both had 161 millimetres land in their rain gauges.
The Upper Rous River had the state's heaviest falls from the overall storm, with 944 millimetres falling in the border zone site near Queensland in the past three days and 1027mm in the January 26-29 period.