3. Stability

Changing Stability Introduction

Photo of a towering cumulus cloud

Several processes in the atmosphere act to modify lapse rates. As a forecaster, you will need an understanding of these processes to obtain the best analysis of stability through a forecast period. Five basic kinds of physical processes can change the stability at a point or in a given local vertical layer.

  1. Diabatic heating and cooling
  2. Advection
  3. Vertical motion of a layer
  4. Penetrative convection
  5. Moistening

In the following sections we will examine each of these processes individually.

In practice several of these processes usually operate simultaneously at the same location, and it may be difficult or impossible to evaluate their effects separately. Therefore, you will need to consider all of these processes when analyzing a sounding.