The Weather Project · Product guide
Australian thunderstorm forecasts
Understand the environment for storm development, the potential severity if storms form, and how those signals combine. Explore regional GFS maps through the state forecast viewers.
Understand the guidance
Coverage means development potential
The coverage field is a 0–100 index of conditions favourable for convective development. It is not the percentage of an area expected to receive storms, or a calibrated storm probability. Instability, moisture, lapse rate and inhibition contribute to the signal.
Severity is conditional
The severity field describes potential if storms develop. It uses instability, lapse rate and an 850–500 hPa wind-shear proxy. A high value does not guarantee storms, hail, damaging wind or a particular storm track.
A development-led composite
The composite uses 75% development and 25% severity, with the severity contribution capped at the development score plus 20. Strong conditional severity therefore cannot overwhelm a weak development signal. All three fields are heuristic indices.
Use the outlook in context
Compare model run and valid time, watch changes as the event approaches, and use current observations, radar and official warnings for immediate decisions. Regional interpolation does not resolve individual cells. Blank or masked areas are not proof of no risk.
Choose your state or territory
Choose Thunderstorm Composite in the viewer. GFS maps step through 3-hour forecast leads; check the available run and valid time on each map.
Explore weather product guides
Check the source, model run, observation timestamp and valid period shown in the live product. Forecast guidance carries uncertainty and is not an official warning.
Standalone state thunderstorm forecasts
Open the dedicated forecast map sequence for your state or territory.