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(5) The possible mechanical lift due to the sea-breeze. There is no doubt that this has often been the cause of thunderstorms. There was a case some years ago of a heavy hailstorm over the Mount Lofty ranges when a light northerly wind and apparently humid drift was lifted by a sea breeze.

(6) A comparison of surface temperature and humidity data from inland suburbs with the radio-sonde station and the possibility of constructions a composite pusdeo-diagram. This construction may be open to question. However we might say that at least a thunderstorm was likely over somewhere in the area. Even if this where not at the spot where it was thermodynamically predicted, such a forecast might be considered sufficiently useful. Such a procedure would be an advance on forecasting a local thunderstorm empirically without such analysis.

Addendum : Note on estimation of vertical currents in a thunderstorm

"The size of the hailstones suggest very strong ascending currents. Some measure of these may be obtained from formulae developed by Jospeh Levine and C.E Buell as follows:

${\overline {\delta G}}={\frac {r}{u}}.{\frac {T_{m}}{h}}.{\frac {\delta _{ps}}{p_{s}}}$(Levine)

or approximately
$V^{2}=2{\frac {R}{u}}.T_{s}.{\frac {\delta _{p}s}{p_{s}}}$ (Buell)

where ${\overline {\delta G}}$ is the mean acceleration.

R and u gas constants equal to 8.3 x 10 and 28.9 respectively

$T_{m}$ = Mean temperature
$T_{s}$ = Surface temperature
$\delta _{p}s$= Pressure oscillation
$p_{s}$ = Surface Pressure
h = height

$\delta _{p}s$ is the pressure "bump" or sudden pressure rise as the thunderstorm passes the locality.

..../The Values of