Evaporative available potential energy-
Analogous to convective available potential energy, except that it is related to the negative buoyancy associated with evaporative cooling of
liquid water within a sinking cloudy air parcel.
Easterly wave-
A migratory wavelike disturbance of the tropical easterlies.
Eddy diffusivity-
The exchange coefficient for the diffusion of a conservative property by eddies in a turbulent flow.
Ecnephias-
A squall or thunderstorm in the Mediterranean.
Eddy flux-
The rate of transfer of a conservative fluid property through a surface by turbulent eddies.
Effective temperature-
The temperature at which motionless saturated air would induce, in a sedentary worker wearing ordinary indoor clothing, the same sensation of comfort as that induced by the actual conditions of temperature, humidity, and air movement. Effective temperature is used as a guide in air-conditioning practice, and, on the comfort chart (American Society of Heating and Air Conditioning Engineers), it appears as a family of curves that serves as one coordinate in defining comfort zones.
Elevated convection-
Convection that originates from an atmospheric layer above the boundary layer.
El nino-
A significant increase in sea surface temperature over the eastern and central equatorial Pacific that occurs at irregular intervals, generally ranging between two and seven years.
Ensemble forecast-
A set of different forecasts all valid at the same forecast time(s).
Entrainment-
In meteorology, the mixing of environmental air into a preexisting organized air current so that the environmental air becomes part of the current; the opposite of detrainment.
Environmental lapse rate-
The rate of decrease of temperature with elevation
Equilibrium vapor pressure-
The pressure of a vapor in equilibrium with its condensed phase (liquid or solid).
Estimated ceiling-
After U.S.weather observing practice, the ceiling classification applied to a ceiling height that is determined in any of the following ways: 1) by means of a convective-cloud height diagram or dewpoint formula; 2) from the known heights of unobscured portions of natural landmarks, or objects more than one and one-half nautical miles from any runway of the airport; 3) on the basis of observational experience, provided the sky is not obscured by surface-based hydrometeors or lithometeors, and other guides are lacking or considered unreliable; or 4) determined by ceilometer or ceiling light when the penetration of the light beam is in excess of normal for the particular height and type of layer, or when the elevation angle of the clinometer or ceilometer-detector scanner exceeds 84°.
Eta vertical coordinate-
A vertical coordinate for atmospheric models defined with a steplike representation of topography, having mountains formed of grid boxes of the model.
Eulerian wind-
In the classification of Jeffreys, a wind motion only in response to the pressure force.
Evaporation-
The physical process by which a liquid or solid is transformed to the gaseous state; the opposite of condensation.
Evaporation fog-
Fog formed as a result of evaporation of water that is warmer than the air.
Excessive precipitation-
Precipitation (generally in the form of rain) of an unusually high rate.
Extended forecast-
A forecast of weather conditions for a period extending beyond three or more days from the day of issuance.
Extratopical cyclone-
Any cyclonic-scale storm that is not a tropical cyclone, usually referring only to the migratory frontal cyclones of middle and high latitudes.
