Figure 24. This is an IR satellite loop of the second MCS. Satellite imagery is overlaid by RUC winds at several pressure levels including 850 mb (white), 700 mb (orange), and 500 mb (yellow). The loop shows how wind shear became more unidirectional with time. Very cold cloud top temperatures approached -80 deg C. is the U.S. government's official web portal to all federal, state and local government web resources and services.