The ability of the NMC and U.K.M.O. models to predict aircraft flight time
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The ability of the NMC and U.K.M.O. models to predict aircraft flight time

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  • Description:
    "Over the years NMC has assembled a variety of techniques by which the quality of forecasts may be evaluated. The S1 score originated more than thirty years ago as a means of determining the skill of sealevel pressure and 500 mb height progs. The SUMAC method, in which the forecasts are verified against radiosonde reports, was begun in the early sixties and expanded in scope in the following years. Programs exist which match the forecasts against analyses, which are taken to be truth. These methods express the accuracy of the prediction in terms of a number such as the S1 score, which is dimensionless, or a quantity such as the RMS vector error, with units of velocity. Scientifically, these statistics are quite acceptable; from a practical or operational point of view, they are deficient, however. This is so because they do not provide satisfactory information to the users of the forecasts. In particular, statistics on vector error are virtually useless for aviation flight planning, because they are not geared to the way airlines operate. The aviation world does not think in terms of vector errors or anomaly correlation coefficients; instead flights arrive ahead of or behind schedule and it is through this difference between forecast flight time, based on the wind predictions, and actual flight time, determined by the encountered winds, that the impact of errors in the forecast is shown"--Introduction, paragraph 1.
  • Content Notes:
    John E. Newell.

    "This is an unreviewed manuscript, primarily intended for informal exchange of information among NMC staff members."

    "July 1987."

    System requirements: Adobe Acrobat Reader.

    Includes bibliographical references.

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    Public Domain
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