> as lemmas

1906 Q. Jrnl. Royal Meteorol. Soc. 32 264 From the Kew curves we might be led to suppose that the velocity in the squall was approximately of the same magnitude as the velocity of the squall line.

1923 W. N. Shaw Air & its Ways 75 The surface boundary of the polar front in this region is called the ‘squall line’.

1950 Jrnl. Meteorol. 7 21/1 The term squall line is among the oldest in meteorology and is perhaps the least clearly defined. Prior to the general adoption..of the frontal theory of cyclones, it was customary to designate as a squall line any line of storms projecting in a general southerly and easterly direction from a depression... With the advent of the frontal theory, some of these lines of storms were redesignated more descriptively as cold fronts... There remained the lines of storms which appear in general in the warm sector of cyclones, roughly parallel to the cold front, and along which there is intense convective activity.

1979 L. J. Battan Fund. Meteorol. ix. 187 Most often the storms regarded as being in the organized class are those that form in lines or bands of thunderstorms, sometimes called squall lines... They commonly are initiated along a cold front, or ahead of, and nearly parallel to it.