What are they exactly? Are they just the shockwave-type effect of the Combine trying to open a portal on Earth? That would explain the portal storms in Ep2, but I've read (from Raising that Bar I think) that portal storms occurred all the time after the Black Mesa Incident and when the Combine took over they stopped them.
Does anyone know what the portal storms really are and why they occur?
Does anyone know what the portal storms really are and why they occur?