A thunderstorm asthma warning system is up and running in Victoria after nine people died in a freak event last year.

A Victorian nurse fighting to save lives during a freak thunderstorm asthma event as she struggled with her own symptoms has backed the state government's new early warning system.

The new monitoring and alert system will warn people about the risk of thunderstorm asthma events up to three days beforehand following the deaths of nine people in 2016.

Nurse Chantelle D'Souza, who was working in the Footscray emergency department during the storm in November, told reporters on Sunday it was a "very surreal" experience.

"It was very surreal and frightening to say the least," Ms D'Souza said, adding that she carried on working despite struggling to breathe herself.

The new forecasting system will help authorities and the public better predict and understand the phenomenon, Health Minister Jill Hennessy said.

"The great challenge with thunderstorm asthma and epidemic thunderstorm asthma was its scale, its severity, and the fact that we did not have a prediction system in place which would enable us to understand what was coming," she said.

As well as the nine fatalities, thousands suffered respiratory symptoms on November 21 as a result of what experts have described as the world's worst recorded asthma thunderstorm.

The storm kicked up dust and pollen, while the moisture in the air from the humid, hot day burst the pollen into hundreds of tiny allergenic fragments, penetrating deep into victims' airways.

The new emergency system will predict the risk of thunderstorm asthma by analysing grass pollen forecasts, weather observations and data such as temperature, wind changes, rainfall and grass coverage.

A traffic-light scale will then identify the risk of epidemic thunderstorm asthma as low, moderate or high.

The forecasting system will run between October 1 - the start of the grass pollen season in Victoria - until December 31.

Warnings and forecasts for thunderstorm asthma will be issued via the Vic Emergency app by Emergency Management Victoria in the same way they issue alerts for bushfire and floods.

The thunderstorm warning system is a collaboration between university researchers, health and emergency authorities, and the Bureau of Meteorology.