🔍 Key Concepts

• Mid-latitude frontal systems and how they move across the central U.S. • Typical seasonal patterns of strong cold fronts in the Midwest river valleys • Difference between air-mass thunderstorms (hot, humid afternoons) and frontal thunderstorms (along cold/warm fronts)

💭 Think About

• Think about when strong cold fronts most often sweep across the central United States and trigger organized lines of thunderstorms. • Consider which season along the Missouri River is known for quickly changing weather and severe squall lines along fronts. • Ask yourself: during which season are river mariners most concerned about fast-moving storm lines tied to passing fronts, not just pop-up heat thunderstorms?

✅ Before You Answer

• Be clear on the difference between frontal thunderstorms (linked to cold/warm fronts) vs. air‑mass or heat‑of‑the‑day thunderstorms. • Recall which season in the Midwest has the highest frequency of severe weather and squall lines along fronts. • Eliminate any season that is typically dominated by more stable, cold air with less convective activity over inland rivers like the Missouri.