rafale

CONT: Les rafales s'expliquent par l'instabilité verticale de la masse d'air. Elles résultent de l'irruption, au niveau du sol, de particules originaires des couches élevées, où la vitesse est très grande en raison de l'absence de frottement.
CONT: Les rafales [sont] matérialisées sur les anémogrammes par des pics filiformes [...]

CONT: It is a much shorter-lived feature than a ""squall"" and is also different in nature, being due mainly to mechanical interference with the steady flow of air; it is, therefore, a pronounced feature of airflow near the ground, especially where there are large obstructions. Other factors, notably temperature lapse rate and vertical wind shear, are important, however, in determining the existence and magnitude of gusts. Such factors may produce gusts in circumstances where mechanical interference with the flow appears to be insignificant, as in ""clear-air turbulence"".
CONT: With gusts to 25.

OBS: ráfaga : término aceptado oficialmente por la Organización de Aviación Civil Internacional (OACI).