Thunderstorm asthma warnings have been issued for parts of Victoria as severe storms are predicted to lash some regions.
The Bureau of Meteorology forecasts that severe thunderstorms are likely to produce damaging winds, large hailstones and heavy rainfall over parts of the Mallee and the Wimmera on Thursday, with the potential for flash flooding.
State health authorities warned residents of the Mallee and Wimmera districts that there was high risk of thunderstorm asthma.
There was a moderate risk of epidemic thunderstorm asthma in the south-west, north central and central (which includes Melbourne) regions of Victoria.
The alert is trigged by a combination of high grass pollen forecast and thunderstorm conditions. The combination of the two can trigger severe asthma symptoms in people who have asthma or hay fever.
Due to increased thunderstorm activity the forecast risk of thunderstorm asthma has increased to high in the Mallee District. This is in addition to the high-risk forecast in Wimmerra District.
— VicGovDH (@VicGovDH) November 10, 2022
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A mass thunderstorm asthma event in Melbourne in 2016 claimed at least six lives and led to thousands of people seeking hospital treatment.
The Victorian health department advised residents to avoid wind gusts before the storm, to stay inside and close windows and doors, and to turn off evaporative air conditioners that draw in air from outside: “Be aware of and act on the development of asthma symptoms including wheezing, breathlessness, tightness in the chest, or a persistent cough, as you may be having an asthma attack.”
The Victorian premier, Daniel Andrews, urged asthmatics to be vigilant on Thursday.
“We know that thunderstorm asthma is a very significant issue, and all of our advice is … at every opportunity to remind the community to be up to date with your asthma plan,” he said.
“It’s not just today, it’s going to be a challenging next little while, with this unsettled weather. All of us have to take these respiratory conditions very, very seriously.”
Thunderstorm asthma events are uncommon but can occur in south-east Australia during grass pollen season, between October and the end of December. Although thunderstorms and high pollen counts often coincide, thunderstorm asthma epidemics do not occur every year.
Victoria Health said on its website: “The forecast should not replace appropriate prevention and good asthma and hay fever management, which is the best way to protect yourself from thunderstorm asthma.”
Particles of grass pollen are typically thought to be too large to get into the lungs to cause asthma, but strong winds and moisture from thunderstorms may cause the pollen to fragment, experts believe.
Thursday’s stormy forecast was due to a surface trough near the Victorian border, which extended into northern South Australia, the BoM said: “An upper trough is also moving across the southeast of the country, enhancing thunderstorms east of the surface trough this morning and afternoon.”
The thunderstorm asthma risk is predicted to be lower on Friday.
