Wow,
I had no idea it was that bad Doug!
Even here in Tucson we get some turbulance when the wind switches from SE to NW, usually sometime around 11 to noon. It's usually not nearly as bad as what you describe but can be sometimes as the velocity increases.
In fact there used to be a trash can on the SE side of the field for those that were brave enough to fly in that stuff. It often was filled with balsa and doped silkspan! I filled it up once. A couple of fairly well known fliers filled it several times! Asphalt is very unforgiving!
As we've aged here and no one is really trying to be a Nats Champ anymore we most often quit flying when it gets rough! Milk Sops all!
Randy Cuberly