🔍 Key Concepts

• Low pressure system and how it affects atmospheric pressure over time • Difference between instruments that measure wind speed, humidity, temperature, and pressure • Why mariners watch trends over several readings, not just a single value

💭 Think About

• Which instrument tells you how the air pressure is changing as a storm approaches and then passes? • If you took readings every hour, which device would clearly show a fall then rise pattern with a low in the middle? • On a ship, which instrument is most closely watched to anticipate changes in weather systems, not just local conditions at a single moment?

✅ Before You Answer

• Identify which option measures atmospheric pressure, not wind, moisture, or temperature • Think about which reading you would log regularly in a weather logbook to track a system’s passage • Confirm which instrument is most associated with forecasting approaching and passing storms