A value of 1.0 is a perfect forecast. The Office is currently installing a new CRAY T3E supercomputer which is expected to give at least 5 times the processing power of the C90. This provides an opportunity to review the operational forecast configurations of the Unified Model. Many customers need timely output on which to base their decisions. The current global model runs deliver output approximately 4 hours after data time, which is too late for many applications.
Decisions therefore have to be based on the regional model or an earlier run of the global model.
In addition, the regional model forecasts have to rely on output from a global model forecast from 12 hours earlier for boundary conditions. It is therefore proposed to exploit the power of the new computer to increase the resolution of the global model to close to that of the current regional model. The existing, later, global run will continue because significant extra data is available, especially from aircraft. Thus an updated and more accurate forecast can be issued 4 hours after data time. The performance of the new global configuration is illustrated in Figs 5 and 6.