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Meteorology

3.7.2 Changes in an air mass

When an air mass is moved from one place to another (advection), it changes

according to the influences it encounters. Nevertheless, by observing the wind,

you can assess where the air is coming from and what it means for the weather
(this does not apply in situations where the weather is influenced by fronts and

pressure systems).

Let’s see how the different air masses affect the weather in Denmark.

3.7.2.1 Summer weather

Wind from the west

It comes as no surprise that Denmark is located in the westerlies belt.

What we are most familiar with

are the cool, moist summers.

These typically occur when the

wind comes from the west or

northwest. Low-pressure systems

move from Scotland and across
Central Scandinavia. Additionally,

we get the passage of more

widespread rain areas, the so-

called fronts.

Weather forecast

With a wind from the north-northwest, it’s an unstable cold air mass moving

across the area. In summer, the air mass is often colder than the surface it

moves over, causing the formation of cumulus and cumulonimbus clouds. The

weather is characterized by showers.

Day temperatures are between 20–25°C. At night, it becomes almost cloudless

due to surface cooling, potentially forming radiation fog.

Flight Theory PPL(A)(UL)/LAPL Henning Andersen, Midtjysk Flyveskole© 2025 299