Surface wind Wind blowing near the Earth's surface. It is measured, by convention, at a height of 10 m above ground in an area where the distance between the anemometer and any obstruction is at least 10 times the height of the obstruction.
Surface pressure is the atmospheric pressure at a point of Earth's surface. It is directly proportional to the mass of air over that point.
The surface of the Earth exerts a frictional drag on the air blowing just above it. This friction can act to change the wind's direction and slow it down -- keeping it from blowing as fast as the wind aloft.
surface roughness"The geometric characteristic of a surface associated with its efficiency as a momentum sink for turbulent flow, due to the generation of drag forces and increased vertical wind shear.
Surface-based Convection - Convection occurring within a surface-based layer, i.e., a layer in which the lowest portion is based at or very near the earth's surface. Compare with elevated convection.
Surface Analysis: The weather map depicting surface weather conditions plotted from reported data or generated by computer models. Surface Analysis maps generally display isobars, fronts and centres of High and Low pressure.
Surface temperature: The air temperature measured in the shade at 1.5 m (or 5 ft) above the ground.
Synoptic: Pertaining to an overall view.
Temperature: In an ideal gas, the average kinetic energy of its molecules.
SURFACE BOUNDARY LAYER The lowest layer of the earth's atmosphere, usually up to 3,300 feet, or one kilometer, from the earth's surface, where the wind is influenced by the friction of the earth's surface and the objects on it.
surface front - See front.
surface pressure - In meteorology, the atmospheric pressure at a given location on the earth's surface.
Surface inversion See Radiation inversion.
Synoptic scale The typical weather map scale that shows features such as high- and low-pressure areas and fronts over a distance spanning a continent.
surface inversion—An inversion with its base at the surface, often caused by cooling of the air near the surface as a result of terrestrial radiation, especially at night.
Surface Weather Chart
An analyzed synoptic chart of surface weather observations.
Surface Hoar- The deposition (sublimation) of ice crystals on a surface which occurs when the temperature of the surface is colder than the air above and colder than the frost point of that air.
Sea-Surface Temperatures
During El Niño events warmer than normal water spreads along the equator into the central Pacific.
SEA SURFACE TEMPERATURE (SST): Surface temperature data collected using IR satellite imagery, buoy and ship data.
Sea Surface Temperatures (SSTs) - The term refers to the mean temperature of the ocean in the upper few meters.
SFC- Surface
SHEAR (WIND SHEAR)- Significant change in wind speed or direction with height. For severe weather this is most relevant if it occurs in the lower troposphere.
Surface Wind: By convention, the term applies to wind velocity at 10 meters height and in unobstructed areas.
Surge: Violent breaking of the waves in the coast, caused by rough seas.
Surface tension on the minute droplets keep them in water form. They are unstable and rupture into ice.
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Surface Based CAPE; CAPE calculated using a Surface based parcel.
NOAA National Weather Service - Cite This Source - This Definition
Browse Related Terms: CAPE, Equilibrium Level, Helicity, MLCAPE, Positive Area, Precision, REP ...
Surface temperature inversion - ground cools and then cools air from below, leaving warmer air above.
surface winds greater than or equal to 50 knots
hail at the surface greater than or equal to 3/4" in diameter,
tornadoes,
Embedded thunderstorms,
Line of thunderstorms, or ...
Surface -- 6 500 ft
/up to 2 km
The heights assigned to the 'divisions' between levels should not be followed slavishly, and assignment of clouds to the various 'groups' should be made with the appearance and composition in mind.
Surface Pressure - The pressure that is read from a barometer but is not adjusted to sea level.
Sustained Winds - The wind speed obtained by averaging the observed values over a one minute period.
SURFACE BASED - Weather systems occurring in the lowest levels of the atmosphere and involving air near or just above the ground. Surface based convection involves air from near the ground to rise.
A surface of equal pressure. Isobaric surfaces are used in upper level charts where geopotential heights are contoured to decribe the upper level features. These charts are typically produced at standard levels such as 850hPa, 700hPa, 500hPa etc.
A surface along which the atmospheric pressure is equal everywhere.
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One surface wind met in many situations is the katabatic wind, which I have observed in impressive intensity in Boulder, Colorado, and which often occurs along the mountain front. It is, in fact, called a "Boulder wind.
Sea surface temperature anomaly(6)
Temperature of emitted energy from the sea surface. SST anomaly = (SST-SST mean), where SST = sea surface temperature. Snow water content and snow water equivalent are different terms for the same parameter.
Frontal Surface
Frost
(Abbrev. FRST) - Frost describes the formation of thin ice crystals on the ground or other surfaces in the form of scales, needles, feathers, or fans.
AILERONS - Surfaces at the rear outboard area of the main wing used to deflect air and create a roll force.
Phreatic Surface: The free surface of ground water at atmospheric pressure.
Automated Surface Observing System (ASOS) Meteorological sensors that record and transmit atmospheric conditions automatically; a component of the modernization program of the National Weather Service.
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Geoid A surface of constant gravitational potential around the Earth--an averaged surface perpendicular to the force of gravity.
Geosphere The physical elements of the Earth's surface, crust, and interior.
Isentropic Surface - A two-dimensional surface containing points of equal potential temperature.
Isobar - A line connecting points of equal pressure.
Isodrosotherm - A line connecting points of equal dew point temperature.
Automated Surface Observing System (ASOS) - A widely used, standardized set of automated weather instruments that provide routine surface observations. (less accurate than conventional measurements) ...
SST - Sea Surface Temperature. The temperature of the near surface ocean water.
Stability - Possessing the ability to return to its original position; suppresses convection.
Changes in sea surface temperatures create shifts in weather patterns. One way is by changing the patterns in the jet stream. In the 1930's, the jet stream was weakened causing the normally moisture rich air from the Gulf of Mexico to become drier.
"near-surface soil heat fluxA quantity measured near the surface of the soil, according to the formula B = λ(dT/dz), where λ is the conductivity of the soil that the heat or moisture is moving through.
CONSTANT PRESSURE SURFACE
A surface along which the atmospheric pressure is equal everywhere.
ASOS: Automated Surface Observing System. A network of instrumented weather stations deployed primarily by the U.S. National Weather Service to make weather observations without observer involvement.
Water Table
The surface separating the upper layer of non-saturated soil and the lower layer of saturated soil.
Black iceThin, new ice that forms on fresh water or dew covered surfaces; it is common on roadways during the fall and early winter and appears "black" because of its transparency.
It occurs from objects, especially pointed ones, when the electrical field strength near their surfaces attains a value near 1000 volts per centimeter.
Radiation FogA fog that forms when outgoing longwave radiation cools the near-surface air below its dew point temperature.
In advisory products, refers to the center position at the surface.Centimeter BurstA solar radio burst in the centimeter wavelength range.
TranspirationWater discharged into the atmosphere from plant surfaces.Transport WindThe average wind over a specified period of time within a mixed layer near the surface of the earth.
Used as a common reference for analyses of surface pressure patterns. Sea rainbow Same as marine rainbow. Sea water thermometer A thermometer designed for use in measuring the temperature of sea water.
caliche Also called hardpan; an opaque, reddish-brown-to-white calcareous material, which occurs in layers near the surface of stony soils in arid and semiarid areas. Calvin cycle The incorporation of CO2 into glucose by enzymatic reactions.
Angle of ReflectionThe angle at which a reflected ray of energy leaves a reflecting surface. It is measured between the outgoing ray and a perpendicular to the surface at the point of incidence (i.e., where the ray strikes).
The acronym stands for Australian Surface Pressure Bogus Data for the Southern Hemisphere).
Boundary Layer - In general, a layer of air adjacent to a bounding surface. Specifically, the term most often refers to the planetary boundary layer, which is the layer within which the effects of friction are significant.
Processes by which traces gases or particles are transferred from the atmosphere to the surface of the earth.
HYDROMETEOR Any any form of atmospheric water vapor, including those blown by the wind off the earth's surface. Liquid or solid water formation that is suspended in the air includes clouds, fog, ice fog, and mist.
Consider an area on the earth's surface. On the sides which face the wind, air will flow into the area, while on the other sides air will flow out.
The amount of force exerted over a surface area, caused by the weight of air molecules above it. As elevation increases, fewer air molecules are present. Therefore, atmospheric pressure always decreases with increasing height.
Landfall: The intersection of the surface center of a tropical cyclone with a coastline.
For condensation to occur at the dew point water vapor needs a surface to condense on. In the atmosphere water vapor starts to condense on microscopic particles suspended in the air: dust, soot, volcanic ash, salt spray, etc.
The cold region in the earth's atmosphere located about 10 km (8 mi) above the surface, at which the usual vertical temperature decrease in the troposphere ceases; by convention, ...
Often, after a cold, cloud free night, we wake to find the ground and other surfaces wet and glistening in the sunlight. The cause of this is a form of condensation called dew.
 See also: Air, Temperature, Water, Weather, Atmosphere
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