Related Clues:

• Preindication
• Foreshadow
• Straw in the wind
• Sign for the superstitious
• Like a good guard
• 'Heads up!,' e.g.
• Chairs
• Overcast sky, say
• See 52-Down
• Heads-up
• Argus-eyed
• Watchful
• Broken mirror, to some
• Soothsayer's clue
• Whistle, for one