29-06-2025
Flood awareness a high priority for Tasmanian BOM hydrologist Abrar Shabren after Fiji childhood horror
Abrar Shabren knows from firsthand experience the deadly dangers of floodwaters.
"It was in our village when I was in year 6 that I saw my friend washed away by floodwaters when we were walking to school," Mr Shabren said.
The devastation of seeing a childhood friend taken by floods in Fiji has led to the Hobart-based hydrologist working at the Bureau of Meteorology (BOM), communicating the risks associated with severe weather events to as many people as possible.
Mr Shabren has worked in Fiji, and was "fortunate to be posted to Casey Station in Antarctica, [and to] Melbourne, Sydney and Brisbane".
"But it was during a trip to Tasmania in 2023 that my wife and I went to Bruny Island, and she fell in love with the place," he said.
"And here we are loving everything about the island state.
"My studies have seen me become a meteorologist and a hydrologist.
The senior hydrologist's first experience forecasting Tasmanian floods was in 2016 when floodwaters almost broke the Launceston levy.
It reinforced to Mr Shabren the differences in flooding seen in the tropics and other parts of Australia in the summer months, compared to that seen predominantly in the colder Tasmanian seasons.
"Riverine flooding in Tasmania varies significantly between winter and summer due to differences in weather patterns, rainfall distribution and catchment conditions," he said.
From mid-autumn to early winter, continuous rainfall from these frontal systems, known as 'autumn rains', particularly affects the western, southern and northern parts of the state, making catchments wet and susceptible to rainfall runoffs.
"The persistent rain saturates the soil, reducing its ability to absorb additional water, which increases the chance of higher stream flows and riverine flooding," Mr Shabren said.
"Winter typically brings more frequent and higher rainfall, resulting in consistent riverine flooding with passing frontal systems."
Mr Shabren said in higher altitudes, snowmelt can further raise river levels, exacerbating flood risks, such as in catchments like the Huon and Meander Valley.
"The ground often remains saturated from continuous rain, causing prolonged flooding and higher water levels.
Catchments in Tasmania can remain saturated into spring, increasing the chances of flooding associated with springtime weather systems such as low-pressure systems off the east coast.
Mr Shabren said summer floods were less frequent but could occur suddenly due to intense, short-duration rainfall events, often catching communities by surprise.
These events are usually associated with thunderstorms or weather systems fed by tropical moisture, which can dump large amounts of rain in a short period.
"These floods are usually more localised, affecting specific areas rather than widespread regions," he said.
The dry ground in summer can lead to rapid runoff, as the hardened soil is less able to absorb water, causing flash floods that rise and fall quickly.
This can also lead to rapid rainfall runoffs and flash flooding as the catchment condition and flood behaviour changes.
Mr Shabren said all seasons require continuous monitoring and preparedness.
The BOM in Tasmania works closely with the State Emergency Service, state government agencies and councils in providing warning service and decision-making advice to the community, he said.
"When all environmental conditions indicate potential riverine flooding, the Bureau of Meteorology issues a Flood Watch product, 1 to 4 days in advance.
"Subsequently, flood warnings are then issued according to the flood service level specifications for Tasmania, which are available on the BOM website.
A Flood Watch is issued when forecast rainfall suggests that local and/or riverine flooding is possible, but uncertainty remains about the exact location and intensity.
It may cover large areas and refer to:
Flood Watch areas may not be covered by formal flood warning services.
A Flood Warning is issued when flooding is more certain, often after rain has begun. It is more targeted, covering specific catchments, and usually includes predicted flood severity.
Find out more by visiting the Flood Knowledge Centre and stay up to date with the latest forecasts, observations and warnings by visiting the Bureau's website and by downloading the BOM Weather app
