A method has been obtained for
the extension of predicted pressure fields of the E.C.M.W.F. until the end of
a vessel’s voyage, in order to determine the optimum nautical routes as a
function of the meteorological conditions through the ROUTES routing system.
The method was designed so that analogous meteorological situations that
existed in the past are blended with the original forecast from the fifth day
until the seventh forecast day, all remaining days are determined only by the
better existing analogous situation in a 5-year-old diagnostic data base.
Results of the processing of
three real voyages in which routes diagnostic data were preserved are shown,
The initial forecast of the E.C.M.W.F. was extended up to the time of duration
of the route. The relative error of the files of pressure forecast was
calculated and graphed for their comparison with the diagnostic pressure files
as well as the relative error of the files of extended pressure forecast
against the diagnostic pressure files for each voyage day. The great circle
track was traced and the optimum route were calculated by means of the ROUTES
system and the duration and speeds for each one of the voyages were compared
using as pressure data entry the diagnostic matrixes sequence, the matrixes of
the original forecast of the E.C.M.W.F. and the matrixes of the extended
forecast. It was found that trajectories optimized with both diagnostic and
extended data offer a better error figure than those calculated with only
forecast data, in addition it becomes evident the greater correspondence
between these tracks and those calculated with diagnostic data. The obtained
results are acceptable as objectives of routing, to have a complete forecast
of a vessel’s voyage.
