Belgium soon to be hit by a "thermal trough"

While the Royal Meteorological Institute (RMI) predicted "overwhelming" heat on Tuesday afternoon across Belgium, the country will experience what is being called a "thermal trough" this Wednesday evening.

“Wednesday evening and overnight, a thermal trough from France will cross our country,” the IRM reports on its website.

What is a thermal trough?

A thermal trough, or "thermal depression," "generally forms in an area with pressures between 1010 and 1015 hPa," reports Météo Belgique. This phenomenon very often results in the presence of a barometric swamp. During this thermal depression, "the sun heats the ground, which, through conduction, in turn heats the air near the ground. Little by little, a mass of warm air will form on the ground. The warm air will then begin to rise as it becomes lighter than the surrounding air." This rise will cause a drop in surface pressure and create the famous "trough." Why "thermal"? Because it's the air temperature that is responsible for the phenomenon.

(MH with Raphaël Liset - Source : Le Soir - Illustration : ©Unsplash)