Figure 6: Objective analysis of geopotential height, temperature, and jet stream axes for 300 hpa on 27 March 1992/12:00 UTC. Geopotential contours: every 60 gpm, isotherms: every 2 C, and jet stream axes denote wind speed more or equal to 30 ms-1; T1 and T2 are trough lines and L1 and L2 the surface depression centres.