The Bureau of Meteorology is hoping a new weather model will lead to more accurate forecasts in the New South Wales south east.
The Bureau says it is changing its modelling later this month for only the third time since data collection began in 1908.
Besides looking at the data from the Indian and Pacific Oceans, the new system includes ocean temperatures, the atmosphere, the land and ice in Antarctica to interpret the physics of long-term weather.
Forecaster, Andrew Watkins, says the new model could eventually lead to other features such as wind data and sunshine hours.
â??We expect there to be improvements in the forecasts or long term outlook we make during autumn and also during summer as well,â?? he said.
â??Going down the track a little further, we'll be able to introduce a whole bunch of things, wind and sunshine hours and things like that.â??
© ABC 2013
16:28 EDT Hail is caused when raindrops are lifted up into the atmosphere during a thunderstorm and then supercooled by temperatures below freezing, turning them into ice balls.