If You Live In Sydney, Go Buy The World's Biggest Umbrella

Get gumboots, get a new raincoat, then prepare to get wet anyway.

Sydney, it's going to be one of those days. One of those really, really wet days. And if you want to get home quickly this evening, or if even just trying to avoid getting totally drenched, good luck.

Heavy storms are heading directly for the city later today. Large parts of the NSW coast could be affected, but as the graphic below shows, Sydney is smack bang in the bullseye of the predicted deluge zone.

Sydney Storm
Yep, not missing. This is the 5pm projected rainfall chart. Dark blue indicates 90-100 pecent chance of heavy rain. Image: Bureau Of Meteorology.

Transport delays and flash flooding are expected in the afternoon and evening, as up to 70mm of rain falls across the city within just a few hours.

To put that amount in perspective, 70mm is more than half the average March rainfall of 130 mm -- and March is Sydney's second-wettest month.

"It's a significant amount," NSW Bureau of Meteorology forecaster Chau Zhi-weng told 10 daily.

"From the afternoon onwards, we can expect the rainfall to intensify,"

"It's possible we'll see some flash flooding -- not widespread flooding -- and probably some transport delays in the afternoon, maybe late afternoon just before the peak hour rush.

"So it's not going to be convenient for people."

Storm in Sydney in October 2018. Image: Getty Images.

This could be the start of a prolonged rainy spell for Sydney.

The forecast charts (below) for this afternoon and tomorrow illustrate that well.

On Thursday evening, the low pressure trough (dotted line) is parked right over the city. Without getting bogged down in meteorological technicalities, that usually means rain.

And for the next few days, Sydney will cop a moist airflow from the sea, where the water is currently quite warm for this time of year. That also means rain.

Air circulates anti-clockwise around a high pressure system, so if you look at the last image (bottom right), you can envisage how that works.

READ MORE: What Can You Do If Your Rental Is Smashed In A Storm?

The bottom line here is that it will almost certainly rain heavily later today in Sydney, with further rain of varying intensity likely for several days.

This is far from the first time Sydney has been in the path of severe weather over the past few months.

In November, the city was hit by a severe storm, when three people tragically died after dangerous road flooding. Sydney's official weather station in the city received double its November average monthly rainfall in just a few hours.

READ MORE: Three Dead, Clean Up Continues After Sydney Storm

Meanwhile, the Bureau of Meteorology is urging people to check for severe thunderstorm warnings. These have not been issued yet, but could be later. We'll keep you updated.

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