Perfect storm brewing for dust to cover the coast
FORECASTERS are closely monitoring the potential for dust storms to reach coastal Victoria over spring and summer as the telltale signs build in the state’s northwest.
Historic below average rainfall in the Mallee has resulted in below average soil moisture, which could conspire to bring more raised dust events to centres including Geelong should the right weather pattern emerge.
Bureau of Meteorology forecaster Steven McGibbony said meteorologists were acutely aware of the raised dust risk “whenever there’s a windy day” in the current climate, although said it was tricky to pinpoint until an event began.
“It’s a tricky one. We rely a lot on an understanding of just how dry it has been in certain parts and when the ground has been dry for a long time, there’s more potential to lift dirt and dust, which can get whipped up in strong winds,” Mr McGibbony said.
“Typically the northwest is the dry and dusty part of the state, so we’d be looking at a day with strong north, northwest winds.
“It’s not uncommon for us to be thinking that, but I guess given it has been quite dry of there lately, yeah, it’s something we think about whenever there’s a windy day.
“We’ve already had a few events where we’ve seen raised dust being whipped up in the northwest of the state, so we already know the conditions are ripe for that.”
Mr McGibbony said spring was known for its windy months, but stressed the need for strong north-northwest winds to be blowing over several hours to provide enough force to push dust to the coast.
The bureau defines a strong wind as anything more than 40km/h averaged over 10 minutes and monitors dust through webcams and satellite data on potential days.
“Spring is probably one of the windiest times of year, so you can get these cold fronts coming through and a long period of northerly winds ahead of them and that would be the ideal set up to see dust in coastal areas, so it’s certainly a possibility in the next couple of months,” Mr McGibbony said.
“If it’s only windy for an hour or so before a change comes through, or the winds die down, it’s not going to be blowing long enough to bring it down to the coast.”
The seasonal outlook for drier and warmer than average conditions for already dusty parts of the country is set to prolong the potential.
The February 8, 1983, dust storm, which preceded the Ash Wednesday bushfires, is considered the worst dust storm to barrel through Geelong in recent memory, while two major raised dust events hit the city in 2008.