Background: Spot fires play a significant role in the rapid spread of wildland and wildland–urban interface fires.

Aims: This paper presents an experimental and modelling study on the flaming and smouldering burning of wood firebrands under forced convection.

Methods: The firebrand burning experiments were conducted with different wind speeds and firebrand sizes.

Key results: The burning rate of firebrands under forced convection is quantified by wood pyrolysis rate, char oxidation rate and a convective term. The firebrand projected area is correlated with firebrand diameter, char density, wind speed, and flaming or smouldering burning. A surface temperature model is derived in terms of condensed-phase energy conservation. We finally establish a simplified firebrand transport model based on the burning rate, projected area and surface temperature of firebrands.

Conclusion: The mass loss due to wood pyrolysis is much greater than that due to char oxidation in self-sustaining burning. The burning rate is proportional to U1/2, where U is wind speed. The projected area for flaming firebrands decreases more rapidly than that for smouldering ones. The firebrand surface temperature is mainly determined by radiation.

Implications: Knowledge about firebrand burning characteristics is essential for predicting the flight distance and trajectory in firebrand transport.