A ceiling leaking after heavy rain is typically a sign of a roof leak. Heavy rain can exacerbate existing issues such as damaged shingles, cracked flashing, or compromised sealants, allowing water to penetrate the roof and enter your home. Its crucial to address the leak promptly to prevent further damage to your ceiling and property. Inspect your roof for any signs of damage and consult with a professional roofing contractor to properly diagnose and repair the issue.