A fog in which the visibility is less than one-quarter mile.

Cirrus, cirrostratus and cirrocumulus.

The semi-permanent, semi-continuous front that encircles the northern hemisphere separating air masses of tropical and polar origin.

A strong, cold, dry west wind of eastern Asia that blows across the plains during winter and carries a yellow dust from the desert.

A hot wind during unsettled summer weather in the Mediterranean.

A small amplitude pattern where winds blow mostly west-to-east.

A rotating "cloud" of dust or debris, near or on the ground, often appearing beneath a condensation funnel and surrounding the base of a tornado.

One to five kilometers’ visibility.

Very intense shower of snow, often of short duration, that greatly restricts visibility and produces periods of rapid snow accumulation.

Very cool, in the summer, refers to more than seven degrees Celsius below normal.