Rasch, Glenn E.

"One of the diagnostic tools used to evaluate analyses generated during the preimplementation test of the 6-hour cycle (Desmarais et al., 1976) is the energy program developed by Miller et al., 1975. The preimplementation test served to evaluate the impact of shortening the update interval of the NMC Final cycle from 12 hours to 6 hours. Based on the results of that test, the shorter update interval is being used operationally. However, the energy differences between analyses made with the 12- hour cycle and those made with the 6-hour cycle were neither completely explained nor understood. Fortunately, for most times and for most energy types, there proved to be very little difference between 6- and 12-hour cycles. But for some energy types, particularly the kinetic energy in the Southern Hemisphere, the differences were fairly substantial. The purpose of this note is to attempt to shed a little more light on why the energy differences occurred"--Introduction.

National Weather Service (NWS)

United States