CONVECTIVE PRECIPITATION

For precipitation production (rain, snow etc.), other conditions being satisfied, there must be a supply of upward motion through the cloud producing the rain, snow, hail or whatever. In convective precipitation, upward motion is provided by the release of convection in an unstable environment..[ Computer models in operational use cope with instability features via parametrisation schemes (q.v.), which model 'ideal' convective towers within each model grid square, taking into account entrainment of dry air, moist convective vigour & depth, temperature structure etc. Algorithms will assign model rainfall to either 'dynamic' or 'convective': the type giving the greatest rate of rainfall is (usually) that which appears on the output chart. ](See also Dynamic and Orographic precipitation)