had a similar incident in the ol' 146 last month.
FL180 at 300 kts (thats fast for a quadrapuff) over nedul when my windscreen started arcing, then the outer pane shattered.
A quick pan issued and a precautionary divert to SOU, with the captain taking PF duties.
As stator vane said, it's a sound that'll live in your memory forever.
BPM