GPs and people with allergies and asthma are being warned that high grass pollen levels are forecast this spring, and they need to be aware of the possibility of thunderstorm asthma events.

In Victoria, thunderstorm asthma forecasts will be available from Monday on the VicEmergency app and website and will run until the end of the year, health authorities say.

However, the state’s Chief Health Officer Dr Brett Sutton says the forecasting system should only be a back-up and he urges patients with asthma to follow their treatment plans.

Epidemic thunderstorm asthma is an uncommon event, where a combination of high pollen levels, strong winds, hot temperatures, air moisture and a cold front trigger severe asthma attacks.