CWA
– County Warning Area
CYCLONE –
An area of low pressure around which winds blow counterclockwise in the Northern Hemisphere. Also the term used for a hurricane in the Indian Ocean and in the Western Pacific Ocean.
DAMBREAK FLOODING
– Dambreaks present a unique flood warning problem. Dams may erode and empty relatively slowly. In these situations, when river forecasts are available, flood warnings and flood statements are used. Dams may also fail catastrophically during a heavy rainfall event or earthquake, resulting in a very dangerous flash flood-type situation. For these events, Flash Flood watches, warnings and statements will be used. Similar action may be required for the failure of certain levees.
DEFORMATION ZONE
(DFRMTN ZN)
DENSE FOG –
A cloud, with its base on the surface, which reduces visibility to 1/4 of a mile or less.
DEW
– Moisture that has condensed on objects near the ground, whose temperatures have fallen below the dewpoint temperature.
DEWPOINT
– The temperature to which the air must be cooled for water vapor to condense.
DEWPOINT DEPRESSION
(TDD)