Français : Trois phases de la formation du coup de chaleur : un cumulonimbus atteint son stage mature sous un courant ascendant qui éventuellement cesse et finalement le courant descendant de haute altitude prend le dessus et réchauffe l'air des compression adiabatique
English: For a heat burst to occur, there needs to be both a dissipating thunderstorm and a hot, dry environment in the mid-levels of the atmosphere, combined with a shallow surface inversion. Thunderstorms develop when moist, unstable air is lifted upwards; the moisture in the cloud eventually condenses and later falls as precipitation. Once the thunderstorm loses its updraft, the thunderstorm is said to be downdraft dominated.
When this happens with a hot and dry atmospheric midlevel in place, the moisture associated with the downdraft evaporates and initially cools this layer, increasing its rate of descent toward the surface. The cooling ends once all the moisture has evaporated, thus causing warming and mixing of the warm (inversion) layer. The heat burst occurs once the warm and dry air descends to the surface.
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