Further computations of 24‐hr pressure changes based on a two‐parameter model

The results of 13 computed 24‐hr forecasts, using the Sawyer‐Bushby (1953) two‐parameter model atmosphere, are discussed, and further computations to investigate the apparent limitations of the model are described. The effects of the neglect of heating of the atmosphere over the sea, of the use of incorrect boundary conditions and of the use of 500‐mb rather than 600‐mb data are investigated. It is concluded that the imposition of artificial boundary conditions can cause considerable errors, although these will not be serious in the region of the British Isles, and that the effects of non‐adiabatic heating of the air over the sea should be included in the computations.