In some low-lying areas the rain forms temporary pools. The water draws minerals and salts to the surface. After the water evaporates the low lying areas are coated with these deposits. The wind in Egypt usually blows from the north, cooling things down in the desert with refreshing Mediterranean air. These prevailing winds have greatly assisted travel on the Nile, which flows from south to north.
Boats can travel with the current north and with the wind south.
The winds are blocked at the Qina Bend by steep limestone cliffs, when the river flows east for a short distance. Temperature changes in the desert can cause gusting winds that blow like a blizzard across the desert surface. These winds howl in the dark cold of the desert night. The winds swirl dust into the air, choking out the sun. The winds can only lift the sand five to six feet off the surface, shifting it across the desert surface in heavy sheets.