Weather and Meteorology Flashcards

What weather feature is characterised by closely spaced isobars on a weather chart?

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.

In which direction does wind flow around a low-pressure system in the Northern Hemisphere?

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.

What does 'Buys Ballot's Law' help a sailor determine?

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.

What type of cloud is most associated with an approaching cold front?

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.

What is the primary cause of sea fog around UK coasts?

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.

On the Beaufort Scale, what wind speed range does Force 6 ('strong breeze') correspond to?

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.