29/03/2012: Despite the threat of thunderstorms, warm sunshine will prevail as Sydney's wettest and coolest March in decades comes to an end, according to weatherzone.com.au.

"It's been 28 years since the city has had a March this cool and this wet, but the month will end on a warm and sunny note on Saturday," Weatherzone meteorologist Brett Dutschke said.

"Thunderstorms will be threatening the area this afternoon and again on Friday, but they will be mostly confined to the Blue Mountains and western suburbs. The city might not get much rain at all in the last few days of the month, just a few rumbles of thunder," Dutschke said.

So far this month, 269mm of rain has been recorded, more than double the long-term average of 129mm. This makes it the city's wettest March in 28 years. Most of the rain fell in the first seven days of the month.

"In early March, well-formed low pressure systems developed over New South Wales. Intially they brought a record wet week and flooding to inland areas, including the Riverina. A few days later an offshore low gave the coast a short wet burst, bringing 127mm to Sydney in under 24 hours. All of this occurred with the aid of La Nina, the weather phenomenon which helps strengthen easterly winds that bring moisture from the warmer-than-normal western Pacific Ocean."

"Now that La Nina is officially over we can expect these easterlies to ease and a trend to near-average rainfall. We might still get the odd heavy downpour due to warmer-than-average seas surrounding the country. These relatively warm waters, which are only slowly cooling, provide the atmosphere with more moisture and hence a better chance of higher-than-average rainfall."

"With La Nina giving way to a near-neutral phase we can expect temperatures to also be near-average for the rest of autumn and winter."

This is already occurring. After a cooler-than-average summer, the coolest in 15 years, March has turned out near-normal, regarding temperatures.

Overall this month, both days and nights are have been almost right the long-term average of 24.7 and 17.6 degrees respectively. Despite this, days have been their coolest in seven years and nights their coolest in four years.

"You have to go back 28 years to find a cooler and wetter March than this one. In 1984, March had 293mm of rain, which forced daytime temperatures to be half-a-degree below average and nights to be more than a degree below average," Dutschke said.

Media Inquiries:

Brett Dutschke
media@weatherzone.com.au
02 9965 9269

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