Residents of south east Australia can expect temperatures to decline as a change comes through by Monday night. A trough moving eastward from central Australia is bringing a cold snap and showers. Ceduna, on coastal South Australia felt the mercury drop 10 degrees in just under 15 minutes. As this trough brings moisture and instability across Victoria and southern NSW throughout Monday, residents can expect cooler temperatures with increased precipitation and a chance of Tuesday storms for Sydney. Cooler temperatures are likely to remain until Thursday, when favourable conditions will see the temperature climb, heading towards a mostly sunny weekend.