Climate change is set to impact Australia’s wool capital as meteorologist’s forecast Hamilton to be 15 per cent drier long term.
The changing position of the subtropical ridge (STR) – a high pressure system that causes dry conditions – has lowered geographically over a number of years, absorbing traditionally higher rainfall towns in the Southern Grampians region.
The climate pattern shift has contributed to western Victoria’s dry conditions, resulting in one above average rainfall year in the past 15.
Bureau of Meteorology agricultural weather division manager Vernon Carr said lower than average rainfall in the Hamilton district was a “worrying effect”.
“The subtropical ridge, which sits over the country in winter, determines where the dry weather is – slowly but steadily this is drifting further south,” Mr Carr said.
“The ridge is the driver that blocks important winter/spring rains.”
BoM’s two decade projections show Hamilton fifteen per cent drier and from .5 to one degree warmer, while the 50 year forecast increases to 20pc. The changes means drier conditions in Horsham and the Wimmera.
“That doesn’t sound like much but over the whole year it is quite an impact – imagine getting nine-tenths of your annual rainfall.” he said.
The forecast pointed towards an increase in extreme temperatures due to higher weather variability.
“(Farmers) will get more 40 degree days than they’re used to,” Mr Carr said.
“How does that affect your grazing and how that affects stock are questions that will need to be considered.”
Mr Carr said Western Victoria’s entire climate pattern would shift and see Hamilton’s change in weather conditions similar to Horsham, Bendigo and Border Town, South Australia.
He said farmers should try to work with the change in weather conditions rather than deny climate change was happening.
“It is happening so you have to work out how to cope.” Mr Carr said.
