Sirocco, a southerly wind in the region of the Mediterranean Sea, blowing from the Sahara. In North Africa the wind is exceptionally hot and dry and is frequently laden with dust. If sufficiently strong, the wind continues across the sea, picking up moisture but remaining hot and dusty. Siroccos may occur at any time of the year but are most frequent and severe during spring. They usually last a day or two. By their withering effect, siroccos can inflict great damage to vegetation. Local names for the wind include khamsin, in Egypt; gibleh, in Libya; and chili, in Tunisia.
Climate, the average condition of the weather in an area for a period of years.
Folks in Montana usually expect snow or rain to fall from the sky, not ash. But the 1980 eruption of Mount St. Helens in Washington flung ash across state lines. What is this gritty, gray stuff?