You can’t create Vector Fields in Cascade.
As of now you can only create them in Maya. You can find plugin here:
Engine\Extras\MayaVelocityGridExporter
And you create VectorField by using Fluid Simulation. Unfortunetly I can’t help you with that as I never used Fluid Simulation in Maya.
Then using this script you export vector field data, and import it to engine.
In Cascade right click on Emitter and in Type Data select GPU Sprites, then right click again on your emitter and under Vector Field you will be able to find Local Vector Field and Global Vector Field.
Add Local Vector Field, click on it, and in details panel select your imported Vector Field.