Soaring

Soaring is the name given to the ability to keep a glider flying, sometime for hundreds of kilometres and many hours, using only the energy available in updrafts in the atmosphere called thermals.

Thermals are convection currents in the atmosphere caused by temperature differences on the ground due to heating from the sun. Thermals are made up of a strongly rising core of air, which is initiated by the hot spot on the ground, surrounded by a ring of descending air. The height of the thermal depends on the atmospheric conditions of the day but can be several thousand metres. If the atmosphere is moist enough thermals are marked by a cumulus cloud that forms at the top, which helps glider pilots locate them.

Gliders locate and circle in the areas of rising air and fly quickly through the areas of falling air, which allows them to stay aloft indefinitely and travel wherever they want to, as long as the energy is available.

Every glider pilot feels the almost magic thrill of being able to keep themself and three quarters of a tonne of fibreglass aloft and going wherever they choose it to go, powered only by the energy they extract from the atmosphere as they go along.

Narrogin is a superb area for soaring all year round. The countryside is essentially flat farmland to the east, north and south, with plenty of out-landing options, friendly farmers and good road access. Tasking to the west is restricted by the Darling Scarp and timbered areas associated with this.

During summer, the band of subtropical highs move south and the weather consists of a progression of these across the area, each separated by a trough line that forms down the west coast and then moves through with the weather system. The cycle generally takes a bit over a week during which the wind backs around the compass, which makes it macro predictable but micro quite variable. Conditions are generally quiet with the wind from the south, gradually get better as the wind moves east then north, booming when the wind is in the northern quarter, then quieter again as the trough moves through and the wind goes around to the west.

During winter, the westerlies which were in the south during the summer move to the north and the same progression happens, but with embedded cold fronts and post frontal conditions replacing the trough lines.