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• Even though the 06Z and 18Z cycles are less skillful, when validated atthe same verification time the later 06Z (18Z) cycle does show consistently better forecast skills than the earlier 00Z (12Z) cycle for short to medium-range forecasts.
• Value of the GFS 06Z and 18Z cycles: a) provide updated initial and boundary conditions for down-stream jobs; b) provide users with updated and more accurate guidance than the earlier 00Z and 12Z cycles for short to medium-range weather forecast.