WAVE OVER SHAWBURY

Pilots are always looking to catch a ride in wave.  This is a brief look at where wave formations might be expected to set up around Shawbury.  Wave is created when strong winds and layers of stable air flow across mountains and high hills.  This air flows up the slope of the hill, and on reaching the top, curls over to flow down the other side.  If conditions are right this airflow then bounces back up and sets up an oscillating wave that can travel for many miles downwind, whilst achieving heights of up to ten times the height of the feature that created them.  Often, but not always, the existence of the wave is signalled by very characteristic lenticular cloud formations or wave bars, lying at right angles to the wind direction.  Here is the front of a typical wave bar over Shawbury.

This next image shows RSGC’s K18 (R43) aircraft tracking along the forward (rising air) edge of a wave bar over Shropshire.

This image below shows RSGC’s K21 (R22) aircraft at 8,000 feet in wave over Snowdonia.  The lenticular shape of another, lower, wave bar can be seen under the port wing.

With his years of experience, together with his knowledge of the local area, club member Mike Osborn has predicted where we can expect to see wave bars setting up in the area around SHY.  The image below overlays Mike’s knowledge on to the chart and shows the 4 main local areas in which we can expect Wave to set up.

This next image shows the RASP wave forecast at a pressure setting of 850 hectopascals overlaid on Mike’s predicted locations.  Note the colour scale indicating the strength of the updraft forecast by RASP.  We can see that it is possible to draw a correlation with Mike’s prediction and this will permit some forward planning for a flying day.

We will be undertaking some more analysis as and when weather conditions suggest wave may form. For those interested in reading more a very detailed FAA publication describing thermal, ridge and wave soaring techniques and safety considerations is at https://members.gliding.co.uk/wp-content/uploads/sites/3/2019/11/Soaring-Chap10-FAA.pdf