A unified scale analysis of the momentum balance of downslope gravity flows is developed to organize previous theories for the case of negligible ambient flow and fixed temperature deficit scale. The values of several nondimensional parameters are evaluated from observations in the literature and used to assess the validity of certain sets of assumptions required for existing theoretical approaches. A new, simple solution is presented which includes both advective and frictional effects. This solution, as well as several other previous solutions, are found to be useful approximations for certain geophysical situations.

[This publication is referenced in the "Synthesis of knowledge of extreme fire behavior: volume I for fire managers" (Werth et al 2011).]