Line Squalls

Long narrow band of rain and violent wind accompanying a barometric depre ion, mostly on the s.e. side, in the n. hemisphere. The wind within this band blows diagonally acro it as if rotating spirally about a long horizontal axis. When these occur in warm weather, the long band constitutes a series of thunder storms; when symmetrically developed, the approaching band of clouds, accompanied by wind, constitutes the arched squall of the tropics. When the local air is rather dry and the advancing air still drier, the clouds give but little rain; dust is the conspicuous feature, and the phenomena are as seen in the Pampero, the Simoom, the Norther and the Bora.