19 November 2004: 06 UTC



Isentropes
The isentropes of the equivalent potential temperature (ThetaE) show a cold-front-inclined crowding zone. The distribtion is typical for a low-level cloud head and its associated frontal cloud band. The surface front (50°N) is indicated by the crowded and inclined isentropes near the surface. This structure of the isentropes indicates instability in this area.