Seriously advanced warning of train approaching!

Was waiting at Metro Center for a Shady Grove bound train this evening, the board said it was expected in 9 minutes however at that moment the lights started blinking, and they did not stop blinking until the train arrived - indeed 9 minutes later!

I've heard of advance warning but that was ridiculous!

Must be a malfunction of the platform lights, every time I've visited WMATA, the lights never flashed well in advance of the train's arrival, they are supposed to flash only 45 seconds before the train pulls into the station.

Yeah, sounds like a malfunction, but also not unheard of. I've seen it happen at Metro Center before, though I've seen it happen on the Glenmont side.