Australian Government Bureau of Meteorology

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The Bureau issues a warning for a G4 geomagnetic storm


Issued Friday 10 May 2024

The Bureau of Meteorology's Australian Space Weather Forecasting Centre has forecast a geomagnetic storm event of level G4 (severe) on the global G-scale.

The Bureau issued a G4 geomagnetic magnetic storm warning at 10.15am 10 May 2024.

The warning issued for this event informs government and critical infrastructure operators so they can take action to mitigate potential impacts on infrastructure assets and essential services.

These geomagnetic storm conditions are expected to arrive at Earth on 10 May 2024, starting at 8.00 pm AEST +/- 10 hours. G4 geomagnetic conditions are expected on 10 May 2024, reducing to G3 with a chance of G4 on 11 May 2024.

The Bureau predicts that these geomagnetic conditions are likely to continue until 06.00 AEST 12 May 2024.

The G-scale is a measure of global geomagnetic activity, which refers to fluctuations in Earth’s magnetic field across the globe. The G-scale ranges from G1 (minor) to G5 (extreme).

The intensity of geomagnetic storms in Australia is usually lower than the planetary average.

This event is a result of four coronal mass ejections observed at 3.36pm AEST and 10.24 pm AEST on Wednesday 8 May 2024, and at 8.24am AEST and 7.36pm AEST Thursday 9 May 2024.

Geomagnetic storms of G4 level can potentially disrupt:

  • critical infrastructure such as power grids, causing power outages
  • satellite services, affecting communications and global position, navigation and timing services that use high-frequency radio communication

The Bureau continues to monitor the situation and will provide updates of significant changes.

If G4 geomagnetic conditions occur, bright auroras will be visible at unusually low latitudes, including dark-sky locations near Sydney and Perth.

The Bureau of Meteorology's Australian Space Weather Forecasting Centre (ASWFC) is the official source of space weather forecasts, alerts and warnings in Australia.

More information: Space Weather, Australian Bureau of Meteorology (