EVEN when the sun is shining, artificial rain is showing on the radar over Laverton.
And some factories in the Altona Petrochemical Complex are making clouds.
David Morrison, of the Bureau of Meteorology, said rain was showing up on the radar because of the steam emissions.
“What you see during clear weather from our radar is call ‘anomalous propagation’,” he said.
“Weather radars are tuned to detect raindrops. However, at some sites, reflection of the radar beam from nearby buildings, towers etcetera will be detected.
“This has the same appearance as small showers of rain but always from the same location.”
He said these “permanent echoes” were typical.
Mr Morrison said Victoria’s Black Saturday bushfires also came up as rain on the radar.
“In extreme situations radar will also detect ash and other debris carried aloft by large fires such as the bushfires of 2009.
“Large insect swarms like locusts and flocks of birds will also be detected if they are present in the radar beam.
“Factory emissions, if containing steam, will condense into cloud when the air is cold enough.”
Above the Qenos manufacturing site, near the Altona/Laverton border, kilometre-wide clouds can be seen on cooler mornings.
Senior environmental manager Les Harman said the factory’s cooling towers emitted more visible steam plumes in cold weather.
“When it’s cold and still, you … get the water vapour off them start to condense and become visible.
“Some mornings it’s very visible. Sometimes it could get up to hundreds of metres high.
“It just adds to the water vapor in the air.
“This year there’s been a lot because of the colder mornings.”
-Goya Dmytryshchak
