An Evaluation of Cirrus Cloud Forecasts from Three Operational Weather Prediction Models

Cirrus clouds are known to impact certain Air Force missions and systems. Mission planners need accurate cirrus predictions in advance of system deployment. This report describes a project to evaluate the ability of operational mesoscale numerical weather prediction models to predict cirrus cloud characteristics. The Air Force Weather Agency (AFWA) MM5 and the National Centers for Environmental Prediction (NCEP) North American Mesoscale (NAM) prognostic models, along with the AFWA Diagnostic Cloud Forecast (DCF) diagnostic algorithm, were considered in the study. Geostationary Operational Environmental Satellite (GOES) imagery channel data were processed to detect ice cloud picture elements (pixels) and to retrieve cloud top height and ice water path as a reference. The presence/absence of cloud ice in the model grid cell was compared with the presence of ice cloud in within-grid-cell pixels. Results showed that the comparison statistics vary significantly by region and to a lesser degree by season. Study results have been summarized for use in providing guidance supporting high altitude laser system tests.
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