Dr. Tom Waite of LSE began to make such refinements during C.STLE
in an attempt to remove ons outstanding defect of this system, ites ine
herent, inability to reveal any detail near the origin, His method ig
described in a separate appendix,
Two difficulties with the system cannct be removed at all. The case
where the hodograph passes directly over the origin is not unlikely and
gives enberrassing results, sinse it, 2 0 and the dose index vanishes except
at the origin.
This result is a6 least sireularly symmetric,
The cther
-
aviceward case {a that in whieh, one or sore elemental wind vectors is radial,
one then has a contimioys altitudes range castributing to the dose
index along a bearing in place of one or two discrete altitudes. This is
in reality precisely the Icind of wind strusture wiieh leads to very intense
narrow bends, but the system es eet up cannot estimate the macmitude of
the dose index along such a bearing, Ore could perhaps hanile this
situation by revising the nethod such thet each 5, poo
iyaltitude interval
made a contribution as determined by the nsan height of wie
torre alcng
@ bearing line through this mean height.
sah@shange wuld introduce
difftioulties in evaluating the sontritu casatona point from several.
hei¢hts since the bearing lines through the
heighte would not in
general coincide,
Qne diffieulty will contime to plague us even with any sort of
refined system. ut this tine it is wry aittioultto obtain a weather
forecast precise enough to ‘juatify the effort which mst be put inta s
good fall-out forecast. Bocause of the inherent uncertainties. in weather
forecasting one is tanptod to conclude that a refined system of fall-cut
forecasting will for the time being be meat usefui for post-shot analysis
and that a detailed fall-out forecast based on a normal weather forecast
would be misleading, The wather forecasting prosently available is of
the highest quality but the cumulative errors resulting from small vearia=
tions about the forecast mean vinds ¢an result in a pronounced chenge in
the fallearh pattern. It appears desirable at thia tine to retain a2
crude system wrich is relatively insensitive to small variations in
weather structure and wrich presents conservative upper limits to the
fall-out hasarde
Del3