[1] The point of view here is Eulerian and the development that follows continues in this perspective.

[2] Note that the instantaneous flux of water vapor into the thunderstorm is not directly equal to the precipitation rate. Many issues influence the rate at which input water vapor falls out of a thunderstorm. Our simplifying assumption is that the higher the input flux, the greater the precipitation rate.

[3] The term "deep, moist convection" is used instead of "thunderstorm" because not all cases of the former involve lightning (and its associated thunder). We wish to avoid excluding non-thundering convection, so we are using the more general term.

[4] The term "stratiform" may not be an entirely accurate description of the precipitation that trails behind a convective line within an MCS, but we will continue to employ it here in view of its widespread usage.

[5] The well-known tendency for flash floods to occur after dark means that the convection can persist well into the night but usually dies off late in the morning of the next day. Redevelopment then takes place during the late afternoon.

[6] The term "evaporation" is being used here to include all forms of phase change that take up heat and chill the air in the process: evaporation, melting, and sublimation. There are many unknowns about the contribution of ice phase condensate to the overall development of convective drafts and their associated inflows and outflows.

[7] Reducing "weather" to ascending water vapor is, naturally, a dramatic oversimplification and there are many weather elements that do not require ascent of moisture, but using this simple idea does illustrate how one begins the task of developing an ingredients-based methodology.

[8] It is interesting to observe that the operational forecaster currently has a greater choice of diagnostic tools to examine model output data than for the evaluation of observed data.