Abstract :
Traditional schemes for parameterization of convection have mainly been developed and tested
for models with horizontal resolution of the order of 100 km. Experiments are undertaken to
test the behaviour of a traditional parameterization scheme for convection, designed for a coarse
resolution, in a numerical weather prediction model when the model resolution is increased. It
is shown that a more detailed forecast of convective precipitation and cloudiness is possible
with the finer resolution and that the reason for this is a better simulation of the mesoscale
circulation and therefore areas with convergence of moisture, necessary for moist convection
to take place. The convergence of moisture is included in the closure assumption for the parameterization
scheme and the importance of the formulation of the closure is therefore studied.
