Those storms which are accompanied with a clear sky, as the northers of the Gulf of Mexico, the harmattan of Africa, &c.
This harmattan, by the way, is a bit of a meteorological mystery.
The dry east wind known as the harmattan blows intermittently from December to March.
The harmattan prevails for several days in succession, and alternates with winds from the south and south-west.
A hot wind, like the harmattan of the Guinea coast, rose and drove the sand before it in clouds.
The mean temperature in the dry season, when the “harmattan” is frequent, is 62 Fahr., in the wet season 86.
The harmattan, a very dry east wind from the African continent, occasionally makes itself felt.