The Jet Stream
The jet stream is a high altitude wind that tends to flow west to east at speeds from 100 to 300 mph. To the north of the jet stream is cold air, to the south it's warm. Below the jet stream is the mixing zone, if the jet stream is traveling at 200 mph or more (orange & red on the chart), then strong and gusting winds will be felt at ground level.
Click on the image for today's chart and predictions for the next few days, on the web page, select the interview time e.g. 6 hours and the right navigation arrow to view. As a general rule, if the orange or red bit is anywhere near Exmouth, it's bad news for beach volleyball.
Just along the beach from the volleyball area, is the Exmouth National Coastwatch Institution (NCI). They operates a weather station with wind speed, direction, barometric pressure and temperature etc.
Not good news for beach volleyball, is when we see the NCI wind speed and gusts readings consistently at or above 4BF (BF = Beaufort Scale), with the maximum (indicated by the red arrows) gusting at 20 Kts (23 mph).
Click the wind speed dial to see the current Exmouth beach wind speed.