On Monday night thunderstorms hit southwestern Sydney, but these were only a taste of what is to come for New South Wales this week.
On Tuesday morning thunderstorms kicked off over central New South Wales between Bourke and Griffith due to a broad low pressure trough. Storms will spread across southern and western NSW this afternoon and evening as the trough deepens causing them to strengthen during the night.
On Wednesday the trough will trigger thunderstorms from Bourke to the South Coast, with the heaviest falls likely on the ranges as far north as the Blue Mountains. On Thursday the trough will trigger storms as far north as the Hunter and as far south as the Victorian border while spreading to the northwest corner of the state. On Friday the trough will begin to move a bit quicker and become more defined as it moves northeast through the state, bringing clearing from the south and west.
These storms have the potential to become severe with flash flooding and large hail a risk with some storms. Most of New South Wales will receive its heaviest week of rainfall since July, with some locations likely to get their heaviest rain since February or March. Sydney is likely to have its wettest week since June with more than 20mm.
In Sydney, showers and storms will arrive on Tuesday night or Wednesday. Thursday and Friday are likely to be the wettest days as the centre of the trough passes over with a significant risk of thunderstorms.
Sydney will then see cloud and showers clearing on Saturday with only a slight risk of showers on Sunday.
© Weatherzone 2012
16:06 EST The weather bureau has implemented a new system of forecasting the seasonal outlook called Predictive Ocean Atmosphere Model for Australia, or POAMA.