several ways. The present code is AFRWX FORM 5D. In particular,
complete instructionshave never been issued for the code and the
manner in which certain portions of the code are used is left to the
discretion of the observer. For example, any number of layers of
clouds can be reported. In sonw instances observers reported as many
aS six layers of clouds with two or three tentha of clouds k each
layer. Thi8 ~ ft consider~le doubt in the mid
of the forecaster u
to the number of tenths of clouds which would be seen by a surface
observer and the number of tenths of clouds which would be operatio~
significant
●
Sime an affirmativeor negative operationaldecision
could depe~ on a difference of one tenth of cloudiness,this was
important,
Also coding i~tructions an needed for the visibility element.
At present, unless the aircraft is flying below clouds near the surface,
this code figure has no significance.
The AFRWX FORM 5D provides for coding the surface wid
direction
to eight points. With experienced observers, the surface wind direction can be determined to thirty-sixpoints and for streamline analyses,
this refinemmt of technique is veq desirable. ‘fherefore,
a six
figure group “66diff”was added to the eti of the regular coded message
on all weather reconndssance flights ordered by the Staff Meteorologist.
Also to aSSi8t In detexnd.ningbroad areas of convective activity
such as might be fo~d
d-
to a convergence of wimis, it was decidad
75
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