Stratiform and cirrus clouds can foretell frontal passage several ______ in advance.

• A. hours
• B. days
• C. weeks
• D. months

Answer: (B)

High clouds in the upper atmosphere, like cirrus, often signal that a frontal system is moving in and that its effects will be felt at the surface soon. Because the upper-level air responds first, you can see these cirrus (and related stratiform cloud layers) several days before the front reaches you. This gives a lead time where the weather system is still offshore or aloft, but its approach is already visible below. If you think in terms of timing, days is the most realistic window for when these cloud patterns indicate an approaching front; options mentioning only hours would be too short for the upper-level signals to translate into surface changes, while weeks or months are not typical for a single frontal passage.