FAA's (and others') definition of wind shear: "Wind shear is a change in wind speed and/or direction over a short distance."

 

So the wind direction doesn't necessarily change; it could also be a change in wind speed only/mainly.

Yep that is correct.  Two flights with ASN demo.  All I can say is I will be buying it.  I really like the textures AS gives.  ASN loads a lot faster.  Xgauge is very nice.  Reminds me of Avidyne in RW.  Nice to have Destination WX too. 

To be back on topic, the combo ASN+ REX4 textures gave a new life to my FSX experience: visually and in flying (see ws posts above). Definetly the magic combo at this moment for those who can spend some money.