Ceiling - The height of the lowest layer of broken or overcast cloud layer. Cold Front - The transition zone where a colder air mass overtakes and replaces a warmer air mass. Usually a cut-off low will lie to the South of the established upper air flow. Cyclone - An area of low pressure. Winds blow in a counter clockwise direction in the Northern Hemisphere and in a clockwise direction in the Southern Hemisphere.
Inclimate weather is associated with a cyclone.
Degree Day - A measure of departure from the mean daily temperature. One degree day occurs when the daily mean temperature is above or below 65 degrees Fahrenheit. Downburst - A strong downward rush of air which produces a blast of damaging wind on or close to the surface. Downslope Flow - Air that descends an elevated plain and consequently warms and dries. Occurs when prevailing wind direction is from the same direction as the elevated terrain and often produces fair weather conditions.