An analysis of Collaborative Convective Forecast Product performance for the 2005 convective season

The Collaborative Convective Forecast Product (CCFP) is an aviation-tailored, spatial forecast of convection aimed at improving decision-making in the National Air Space at strategic time frames (2-6 hours). The CCFP is defined as a set of polygons that each have a set of attributes that are thought to be meaningful for providing guidance in the routing of air traffic. This set of attributes includes expected coverage of convection, forecaster confidence, coverage trends, motions, and expected echo tops. Each of these attributes can take on one of several pre-defined categorical values. The attributes that appear to be most crucial to decision makers include coverage, confidence, and echo tops. The CCFP polygons are also expected to only be issued when they meet so-called CCFP minimum requirements. These requirements state that the polygon will be at least 3000 sq. miles in size, have at least 25% coverage of 40 dBZ composite reflectivity and have at least 25% coverage of observed echo tops at least 25,000 ft above mean sea level.

Previous verification work has focused primarily on the observed coverage aspect of the CCFP. Expected coverage is perhaps the most fundamental aspect of CCFP performance that is of direct relevance to the routing of air traffic. Additionally, past work has focused on the aggregate of all forecast polygons associated with a given forecast issuance. Such an approach yields overall performance information that is incomplete. A more thorough evaluation of the CCFP can be obtained by analzing the forecasts on a per-polygon basis instead of a per-issuance basis.

In this work, CCFP performance will be analyzed on a per-polygon basis for the period 1 March 2005 through 25 October 2005. Observed coverage statistics will be generated using National Convective Weather Diagnostic (NCWD) data. Echo top information from the Corridor Integrated Weather System (CIWS) will be used for the first time to validate the echo top forecast information contained within the CCFP. The addition of echo tops to the CCFP analysis allows for complete evaluation of the CCFP minimum requirements along with the separate echo top forecast category. This analysis will provide insight previously unavailable into the performance of the CCFP and will prove useful in the design and modification of future CCFP forecast criteria.