On a synoptic scale, isentropic analysis is associated with weather fronts : warm fronts are found where the wind crosses lines of a chosen potential temperature from lower heights to higher ones, while cold fronts are where the wind crosses descending heights. Synoptic clouds and precipitations can thus be better found with these areas of advection than with conventional isobaric maps. From a mesoscale point of view, an air parcel moving vertically will cross isolines of potential temperature and it will be unstable if the value of those lines decrease with altitude, or stable if they increase.