🔍 Key Concepts

• Tropical wave structure and how weather changes as it approaches • Typical weather progression in the tropics (before, during, and after a disturbance) • Difference between pre-frontal and post-frontal weather vs. tropical systems

💭 Think About

• Think about what conditions a mariner would usually see before the main disturbance arrives in a tropical area. • Consider whether the worst weather (heavy rain, storms, big seas) is usually ahead of or with/behind the tropical wave. • Ask yourself: if you were planning a voyage and a forecast mentioned an approaching tropical wave, would the initial period be more favorable or already severe?

✅ Before You Answer

• Clarify what a tropical wave is (a low-pressure trough moving westward in the tropics, not yet a full storm). • Distinguish between the leading edge and the main body of the disturbance: which one typically has the worst weather? • Check which option describes conditions immediately ahead of the wave axis, not what happens if it later develops into a depression or storm.