The Global Cloud Re-Analysis at the Air Force Weather Agency

Air Force Weather (AFW) has documented requirements for real-time cloud analysis to support DoD missions around the world. To meet these needs, AFW utilizes the Cloud Depiction and Forecast System (CDFS) II system to develop an hourly cloud analysis. The system creates cloud masks at pixel level from 16 different satellite sources, diagnoses cloud layers, reconciles the pixel level data to a regular grid by instrument class, and optimally merges the various instrument classes to create a final multi-satellite analysis.

The time sensitive nature of some DoD missions requires that an analysis be created as quickly as possible after a given hour. Currently, CDFS II creates an analysis at thirteen minutes after the hour of interest to balance operation needs with available satellite data. While this does produce a skillful analysis, it has been long recognized that much of the satellite data available for a given hour arrives too late to be available for the analysis. Many of the DoD missions do not carry such stringent time requirements and may be able to wait some time if doing so increases the skill of the analysis considerably. Missions of interest include the development of cloud climatologies and statistical post processing of NWP cloud information. In addition, a more complete analysis would provide a better source for validation. To this end, AFW has undertaken to examine the potential value of a cloud re-analysis that would be created some time after the given hour of interest in an effort to maximize the use of available data and minimize the overall global pixel age.

This presentation will present the results of efforts to create the cloud re-analysis including the methodology, impact on global pixel age and on the overall cloud characterization.