Lightning strikes near Camden today.Storms have begun forming in the Blue Mountains this afternoon, bringing the most widespread storm activity in the state this season.
Showers have started developing, marking a shift from a sunny, dry spell to more humid and unstable weather, Weatherzone meteorologist Mellissa MacKellar said.
A high pressure ridge provided plenty of sunshine in Sydney yesterday, with a top of 21 degrees in the city and 23 in the west.
Overnight this stubborn high was replaced by a low pressure trough, bringing widespread instability and causing cloud to blanket the city.
Sydney can expect isolated showers this afternoon, with five to 10 millimetres in places.
Suburbs in the west near the Blue Mountains may get up to 20 millimetres of rain, as thunderstorms form along the ranges.
Showers should ease overnight, but there will be a similar story tomorrow as the trough lingers over the state.
The western suburbs again have the best chance of thundery action in the afternoon.
Elsewhere in Sydney should be drier than today, with only a few isolated showers totalling two to five millimetres in some places.
It will be generally dry on Wednesday as a weak high pressure ridge builds over the state.
Another trough should then form on Thursday, ending the week with the chance of another burst of thundery showers on Friday.
In total, parts of Sydney could get up to 30 millimetres of rain this week. This is more than we have had in the past three months.
The outlook is then brighter for the weekend, which should be mostly sunny.
Sydney weather statistics can be seen here.
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This story Administrator ready to work first appeared on Nanjing Night Net.