KRONFELD ON GLIDING AND SOARING.pdf - Lakes Gliding Club

CLOUD AND THUNDERSTORM SOARING 221
such storms. Especially suitable for soaring are " thunderstorm
fronts."
These " fronts " consist of cold air that pushes itself
under warm air. While the cold air moves forward, rolling
slowly over the earth like honey spilt upon a table, the great
thunder clouds are formed in the dividing layer between
the cold and the warm air, and, with the cold air front,
stretch out to form a long line.
From a mountain it is particularly easy to watch the
approach of a thunderstorm. Here, as in cloud soaring, it is
advisable to obtain as much height above the hillside as is
possible. The forces of the approaching front will soon
begin to make themselves felt, and as in cloud soaring, we
suddenly find ourselves climbing strongly, or we become
aware of upwind over spots where there was formerly none.
Now is the time to travel with the storm, but one strict
rule must be observed : always keep in advance of it.
If we take this rule to heart, we need have no fear in the
presence of this most glorious spectacle of nature. Again
and again the lightning flash may light up the gloomy
cloud-wall which draws ever nearer, and the thunder may
roar as mightily as it will, but the soarer will hasten on
before them both.
It is not always possible to start before the storm front
at the right moment. But even if we miss it, thunderstorm
soaring is possible, though with increased precautions.
Very often the wind drops before the beginning of a squall
or dies away altogether. It is out of the question to start
in this " calm before the storm."
In order to leave the slope we must watch keenly for
the sudden, sharp beginning of the thunder squall, and when
this comes it is an affair of seconds. He who starts one
moment too late will find himself caught in a true witch's
cauldron of thunderstorm eddies and gusts, which may be
most dangerous for plane and pilot if they occur close to
the slope and before any great height has been gained. With
the squall comes heavy rain or even hail, and immediately
afterwards great masses of cloud generally drift low and
shroud the mountains in mist while they unload themselves
on the earth beneath.