In synoptic meteorology, a sudden and large drop in atmospheric pressure recorded by a barometer typically indicates the approach or development of which weather condition?

Introduction / Context:
Barometric pressure is a key indicator of large-scale weather systems. Rapid changes often precede significant weather events. Interpreting the sign and magnitude of pressure tendency aids short-term forecasting for mariners, aviators, and field engineers.

Given Data / Assumptions:

• Observation: sudden, marked fall in pressure.
• Mid-latitude conditions with developing or approaching cyclonic systems.
• No local station anomalies (instrument failure) assumed.

Concept / Approach:
A low-pressure system (cyclone) is associated with convergent surface winds, ascending air, and cloud/precipitation development. A sharp fall in pressure signals deepening cyclogenesis or the approach of a well-developed low, frequently accompanied by strong winds and storms. While rain may accompany, the defining feature of a large rapid fall is storminess rather than simple precipitation.

Step-by-Step Solution:

Verification / Alternative check:
Historical storm records show rapid pressure falls (e.g., “bomb cyclones”) precede gale-force winds and severe weather; synoptic charts display tightening isobars.

Why Other Options Are Wrong:

• Rain: Possible, but not as diagnostic as a storm for a large sudden drop.
• Cold wave: Often linked to high pressure and clear skies after a front.
• Fair weather: Correlates with rising or steady high pressure.

Common Pitfalls:
Confusing local convective showers (minor pressure changes) with synoptic-scale pressure falls that signal storms.

Final Answer:
storm