“were there no visual cues? Did the storm block the flight crew from seeing the plane was falling?”
Most likely there was nothing to see outside, however, there were plenty of instruments inside to tell them they were descending, had a nose up attitude, and needed to pitch down and power up. There are backup instruments plus several sets of redundant primary instruments.
There is a line in the main article that said whenever the crew would take proper corrective action the alarm bells would sound telling them they were wrong. In short, there was a tremendous instrument failure with mis-direction. The crew apparently could not overcome “the double whammy.”