A Performance Assessment of The National Ceiling and Visibility Analysis Product.

Abstract

Intoduction: In the context of pre-flight planning, this evaluation is carried out to measure the ability of the National Ceiling and Visibility Analysis product (NCVA) to properly characterize categorical flight conditions?– ceiling and visibility?– across the Continental United States (CONUS). In performing a comprehensive assessment we evaluate individual attributes of the NCVA, including categorical flight conditions, confidence fields, ceiling, visibility, and issuance frequency. The skill assessment is performed using a cross- validation technique, where portions of the observational dataset are selectively removed to arrive at a measure of interpolation error in between individual METAR sites (Neter 1996). The main purposes of this evaluation are to: 1) Assess the quality of the NCVA product with respect to a baseline analysis. 2) Evaluate the effect on the NCVA of a satellite-based cloud mask. 3) Measure the potential value of NCVA?’s frequent update cycle to the flight-planning process. 4) Determine if NCVA?’s performance compares well to the operational Weather Depiction Analysis, a product specifically referenced in the NCVA Concept of Use.