abbreviation used in National Weather Service text products for the term In-Cloud Lightning
frozen water; the solid form of water substance
a time of widespread glaciation
any one of a number of crystalline forms of ice that may be barely visible to the naked eye
small particles whose molecular structure has a structure similar to frozen water (ice), allowing the formation of an ice crystal. These particles help liquid water freeze at temperatures above -40°C (-40°F). Minerals, soot, organic matter, and sulfates can act as ice nuclei.
also known as sleet. Pellets of ice composed of frozen or mostly frozen raindrops or refrozen partially melted snowflakes. These pellets usually bounce after hitting the ground or other hard surfaces.
abbreviation used in National Weather Service text products for the term Impulse
a band of low clouds, arranged parallel to the low-level winds and moving into or toward a thunderstorm. Inflow bands that are curved cyclonically (counter-clockwise) could suggest the presence of a mesocyclone.
a distinct feature on the radar characterized by an indentation in the reflectivity pattern on the inflow side of the storm. The indentation often is V-shaped, but this term should not be confused with V-notch.
radiation that is less energetic than visible radiation and more energetic than microwave radiation; the radiation emitted by the earth’s surface or atmosphere. This is also a type of satellite imagery.
incoming solar radiation; sunshine
the tendency for an object, if moved, to accelerate in the direction of initial movement; in particular for meteorology, the tendency for air parcels that are warmer than their environment to accelerate upward after being lifted
a scientific intergovernmental body set up by the World Meteorological Organization (WMO) and by the United Nations Environment Programme (UNEP). It provides the decision-makers and others interested in climate change with an objective source of information about climate change. The IPCC does not conduct any research nor does it monitor climate related data or parameters. Its role is to assess on a comprehensive, objective, open and transparent basis the latest scientific, technical and socio-economic literature produced worldwide that is relevant to the understanding of the risk of human-induced climate change, its observed and projected impacts, and options for adaptation and mitigation.
a measure of the molecular activity of a substance or the sum of the total energies of all molecules in a specific mass. In an ideal gas, internal energy is directly proportional to the temperature of the substance.
also known as the metric system. The base units are meters (length), kilograms (weight), Kelvin (temperature), and seconds (time). It is the world's most widely used system of units--even the United States uses it, mainly in science.
in meteorology, a reversal of the normal atmospheric temperature gradient with height (normal is temperature getting cooler with increasing height). An inversion is present in the lower part of a cap.
brilliant spots or borders of colors in clouds, usually red and green, caused by diffraction of light by small cloud particles. It is usually observed in thin cirrus clouds within about 30° of the sun and is characterized by bands of color in the cloud that contour the cloud edges.
lifting of air that is traveling along an upward-sloping isentropic surface. Isentropic lift often is referred to erroneously as overrunning. Situations involving isentropic lift are often characterized by widespread stratiform clouds and precipitation.
a line connecting points of equal pressure
a line connecting points of equal dew point temperature
a line connecting points of equal precipitation amounts
a line connecting points of equal wind speed
a line connecting points of equal temperature
having equal or constant temperature with respect to either space or time