RYA Day Skipper Weather and Meteorology 2 — Questions and Answers
Question 1: What weather feature is characterised by closely spaced isobars on a weather chart?
- Calm conditions
- Strong winds due to a steep pressure gradient (Correct answer)
- Fog
- High pressure
Correct answer: Strong winds due to a steep pressure gradient
Closely spaced isobars indicate a steep pressure gradient, which produces strong winds. The closer the isobars, the greater the pressure difference over a short distance, and the stronger the wind.
Question 2: In which direction does wind flow around a low-pressure system in the Northern Hemisphere?
- Clockwise
- Anticlockwise (Correct answer)
- Directly towards the centre
- Directly away from the centre
Correct answer: Anticlockwise
In the Northern Hemisphere, wind circulates anticlockwise around a low-pressure system (cyclonic). This is due to the Coriolis effect acting on the pressure gradient force.
Question 3: What does 'Buys Ballot's Law' help a sailor determine?
- The height of waves
- The approximate direction to the centre of a low-pressure system from the wind direction (Correct answer)
- The tidal range
- The visibility forecast
Correct answer: The approximate direction to the centre of a low-pressure system from the wind direction
Buys Ballot's Law states that if you stand with your back to the wind in the Northern Hemisphere, low pressure is to your left. This helps locate the centre of approaching depressions.
Question 4: What type of cloud is most associated with an approaching cold front?
- Cirrus
- Cumulonimbus with heavy showers and possible thunderstorms (Correct answer)
- Stratus
- Fair-weather cumulus
Correct answer: Cumulonimbus with heavy showers and possible thunderstorms
Cold fronts are characterised by a narrow band of cumulonimbus clouds producing heavy rain, possible thunderstorms, and squally winds, followed by clearer conditions with cumulus clouds.
Question 5: What is the primary cause of sea fog around UK coasts?
- Cold air over warm sea
- Warm, moist air moving over cooler sea surface, causing the air to cool below its dew point (Correct answer)
- Volcanic activity
- Heavy rainfall
Correct answer: Warm, moist air moving over cooler sea surface, causing the air to cool below its dew point
Sea fog (advection fog) forms when warm, moist air moves over a cooler sea surface. The air cools below its dew point, causing water vapour to condense into fog. It is common in spring and early summer.
Question 6: On the Beaufort Scale, what wind speed range does Force 6 ('strong breeze') correspond to?
- 17-21 knots
- 22-27 knots (Correct answer)
- 28-33 knots
- 34-40 knots
Correct answer: 22-27 knots
Force 6 on the Beaufort Scale corresponds to 22-27 knots (strong breeze). At this force, large waves form, white foam crests are extensive, and sailing becomes uncomfortable.
RYA Day Skipper Weather and Meteorology 2
What weather feature is characterised by closely spaced isobars on a weather chart?