Cloud Curve Algorithm Test Program

Abstract

This project had three main objectives: (1) to test variations in the cloud curve algorithm (CCA) methodology to determine the superior algorithm configuration for use with the Air Force Weather Central, Global Spectral Model (AFGWC GSM), (2) to perform inter-model comparisons between CCA (using the AFGWC GSM) and AFGWC's current cloud forecast models (5LAYER in the extratropics and TRONEW in the tropics), persistence and diurnal persistence (used in TRONEW), and (3) to perform inter-model comparisons between CCA (using the AFGWC GSM) and the Geleyn scheme used until May 1985 by the European Centre for Medium-range Weather Fore casts (ECMWF) and using the AFGWC GSM. The basic-CCA approach is to generate relative humidity (RH)-to-cloud conversion curves by relating cumulative frequencies of NWP model forecasted RH to cumulative frequencies of analyzed cloud amount. once the curves are computed, they can be used to convert an RH forecast to a cloud forecast. The cloud forecast skill of CCA (using the AFGWC GSM) compared to 5LAYER (extratropics) and TRONEW (tropics) varied by season, geographical region and forecast interval.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Feb 28, 1992
Accession Number
ADA253918

Entities

People

  • Robert N. Trapnell Jr.

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Air Force
  • Algorithms
  • Atmospheric Sciences
  • Cloud Cover
  • Databases
  • Geography
  • Humidity
  • Meteorology
  • Middle East
  • North America
  • Northern Hemisphere
  • Oceans
  • Plastic Explosives
  • Southern Hemisphere
  • Three Dimensional
  • Weather
  • Weather Forecasting

Fields of Study

  • Environmental science

Readers

  • Atmospheric Science/Meteorology
  • Regression Analysis.