Which is a common first indicator of bad weather approaching
A. ?a buildup of dark clouds
B. ?a decrease in wind speed
C. ?a glassy sheen on the water surface
D. ?the development of a fog bank
The correct answer and explanation is:
Correct Answer:
A. A buildup of dark clouds
Explanation:
The buildup of dark clouds is a common first indicator of bad weather approaching, as it signals the formation of storm systems or weather disturbances in the atmosphere. Here’s a detailed breakdown of why this is the correct answer and how it relates to weather prediction:
1. Understanding Clouds and Storm Formation
Dark clouds, particularly cumulonimbus clouds, are associated with severe weather conditions like thunderstorms, heavy rain, or even hail and tornadoes. These clouds appear dark because they are dense and thick, holding a large amount of water vapor and droplets, which block sunlight from passing through. As these clouds grow taller, they indicate strong upward movements of air (updrafts), a key factor in storm development.
2. Why Other Options Are Less Reliable Indicators
- B. A decrease in wind speed: While changes in wind speed can sometimes indicate approaching weather changes, this is not always consistent. For example, some storms, such as hurricanes, are preceded by calm conditions (the “calm before the storm”), but others may bring increasing wind speeds.
- C. A glassy sheen on the water surface: This phenomenon is usually an indicator of still weather rather than impending bad weather. Calm water surfaces can occur when wind and disturbances are minimal, often preceding high-pressure systems, not storms.
- D. The development of a fog bank: Fog usually forms when warm, moist air cools rapidly, condensing into tiny water droplets near the ground. While fog can reduce visibility, it is generally not associated with severe weather but rather with stable atmospheric conditions.
3. Why Dark Clouds Are Key
Meteorologists use cloud observations as one of the primary tools to predict storms. The presence of dark, towering clouds is often the first visible sign that atmospheric conditions are shifting, such as increasing humidity and unstable air masses. By watching for these changes, individuals can prepare for worsening weather conditions well before they arrive.