In the first stage of convective forecasting, one needs data about the current weather situation, or observations to make a diagnosis. A diagnosis is the first step towards a forecast or prognosis. One can compare that with a model analysis and, if the model made a reasonable analysis, use it as a tool to predict the evolution of the weather in future. Numerical models occasionally predict the development of convective storms quite well, but often they predict too much or little convection and at the wrong location. Therefore it is important to use one's own understanding of the weather to judge if model forecasts are reasonable. It may be necessary to make small or big adjustments to the model forecast or even completely disregard it.

A recommended way to start making the actual forecast is to use the ingredients-based methodology in a very literal way. First, one should know first where convective instability is present or may develop and secondly whether there will be any trigger mechanisms available to start-up the convection.