Question 1

In the northern hemisphere, air flows around a low pressure system…

Accepted Answer

Anticlockwise and inwards — Anticlockwise round a low (Buys Ballot: back to the wind, low on your left). Lows bring the fronts, the wind and the rain.

Question 2

The classic sign of an approaching warm front is…

Accepted Answer

Cloud lowering and thickening from high cirrus, backing wind, falling barometer — High wispy cirrus thickening and lowering over hours, the glass falling, wind backing — rain arrives as the front does. The cold front behind clears it with squalls and a veer.

Question 3

A sea breeze on a sunny summer day blows…

Accepted Answer

From sea to land, building in the afternoon — Land heats faster, the air rises, sea air flows in to replace it — onshore breeze building through the afternoon, dying in the evening, often reversing at night.

Question 4

A rapidly falling barometer usually warns of…

Accepted Answer

An approaching depression — wind and rain — Fast fall = vigorous low approaching. Rate matters: a few millibars an hour is a serious blow coming.

Question 5

Caught out in deteriorating weather, an early prudent action is…

Accepted Answer

Reef early, secure the boat, update your position and consider ports of refuge — Reef while it is easy, harness and lifejackets on, hatchboards in, hot food early, log a position, and review the plan — including the escape ports you wrote down before leaving.

Question 6

High wispy cirrus thickening into a milky halo-ed sheet usually announces…

Accepted Answer

A warm front a few hundred miles away — wind and rain in 12–24 hours — Cirrus → cirrostratus (halo) → lowering, thickening layers is the depression’s calling card, in order.

Question 7

A towering anvil-topped cumulonimbus means…

Accepted Answer

Squalls, heavy rain, possibly thunder — wind that arrives violently and shifts — The cold front’s and the heat-of-the-day’s cloud. Reef before it arrives, not during.

Reading the sky and the map

This lesson is part of a paid course