Weather — page 26 of 38

3,760 terms including subtopics (3,094 terms filed directly here)

Subtopics

Climate Change 922 terms
Hurricane Weather 51 terms

Weather terms

Polar explorer Polar explorer A person working for a long time at one of the polar observing stations. Russian word is "polyarnik."
Polar Front A semipermanent, semicontinuous front that separates tropical air masses from polar air masses.
Polar Jet Marked by a concentration of isotherms and strong vertical shear, this jet is the boundary between the polar air and the subtropical air.
Polar Jet Stream Used interchangably with Polar Jet; a jet stream marked by a concentration of isotherms and strong vertical shear, this jet is the boundary between the…
Polar low Polar low Small, shallow depression which forms mainly in winter over some high-latitude seas within a polar or arctic air mass.
Polar night Polar night In polar regions, the portion of the year when the Sun does not rise above the horizon.
Polar Orbiting Satellite A weather satellite which travels over both poles each time it orbits the Earth. It orbits about 530 miles (850 km) above the Earth's surface.
Polar vortex Polar vortex Large-scale cyclonic circulation in the middle and upper troposphere centered generally in the polar regions.
Polarization Radar A radar which takes advantage of ways in which the transmitted waves' polarization affect the backscattering.
pollen Mature microspores of seed plants.
Pollutant Any inorganic or organic substance that contaminates air, water or soil. Generally, any substance introduced into the environment that adversely affects…
Pollution A resource that is out of place. Generally, the presence of matter or energy whose nature, location or quantity produces undesired environmental effects.
Polyvinyl Chloride (PVC) A type of plastic used to make pipe and fittings for water distribution and irrigation.
Pondage (1) The holding back of water for later release for power development above the dam of a hydroelectric plant to (a) equalize daily or weekly fluctuations…
Ponding In flat areas, runoff collects, or ponds in depression and cannot drain out. Flood waters must infiltrate slowly into the soil, evaporate, or be pumped…
Pool A deep area of a stream between rapids or where the current is slow.
Pool Height The height of the water behind a dam. (Various datums may be used and various pool heights may be used, e.g., conservation pool, flood control pool, etc.)
POP Contraction of "Repopulation", often used as a shortened term for the re-spawn of monsters.
Popcorn Convection Slang for showers and thunderstorms that form on a scattered basis with little or no apparent organization, usually during the afternoon in response to…
POPS Probability of Precipitation
Population the totality of items or units of material under consideration.
Porosity The ratio of the volume of void space to the total volume of an undisturbed sample.
POS Positive
Positive Area The area on a sounding representing the layer in which a lifted parcel would be warmer than the environment; thus, the area between the environmental…
Positive Cloud to Ground Lightning A CG flash that delivers positive charge to the ground, as opposed to the more common negative charge.
positive feedback the process in which an initial change will bring about an additional change in the same direction.
Positive Vorticity Advection (Abbrev. PVA) - Advection of higher values of vorticity into an area, which often is associated with upward motion (lifting) of the air.
Positive-tilt Trough An upper level system which is tilted to the east with increasing latitude (i.e., from southwest to northeast).
Post-Flare Loops In solar-terrestrial terms, a loop prominence system often seen after a major two-ribbon flare, which bridges the ribbons.
Post-storm Report A report issued by a local National Weather Service office summarizing the impact of a tropical cyclone on it's forecast area.
Post-tropical Cyclone A former tropical cyclone. This generic term describes a cyclone that no longer possesses sufficient tropical characteristics to be considered a tropical…
Potential Energy Energy available due to position.
Potential Temperature The temperature a parcel of dry air would have if brought adiabatically (i.e., without transfer of heat or mass) to a standard pressure level of 1000 mb.
Potential Vorticity This plays an important role in the generation of vorticity in cyclogenesis, especially along the polar front.
Powder Snow Dry, loose, unconsolidated snow.
Power Authority to do. One has the power to do something if he is of legal age. Also, used as "powers," the term refers to authority granted by one person to…
PPI Plan Position Indicator
PPINE P lan P osition I ndicates N o E choes, referring to the fact that a radar detects no precipitation within its range.
PQPF Probabilistic QPF; a form of QPF (see below) that includes an assigned probability of occurrence for each numerical value in the forecast product.
PRBLTY Probability
PRBLY probably
PRCP Precipitation
Pre-Frontal Squall Line A line of thunderstorms that precedes an advancing cold front.
Pre-Frontal Trough An elongated area of relatively low pressure preceding a cold front that is usually associated with a shift in wind direction.
Pre-Hurricane Squall Line It is often the first serious indication that a hurricane is approaching. It is a generally a straight line and resembles a squall-line that occurs with a…
PRECD Precede
Precession The comparatively slow torquing of the orbital planes of all satellites with respect to the Earth's axis, due to the bulge of the Earth at the equator…
precession (of the equinoxes) the slow clockwise motion of the equinoxes along the path of the earth's orbit due to the wobble of the earth's axis.
Precipitable Water Measure of the depth of liquid water at the surface that would result after precipitating all of the water vapor in a vertical column over a given…
Precipitation The total measurable amount of water received in the form of snow, rain, drizzle, hail, and sleet.
Precipitation Attenuation The loss of energy that radar beam experiences as it passes through an area of precipitation.
Precipitation Mode The standard, or default, operational mode of the WSR-88D. The radar automatically switches into precipitation mode from clear-air mode if the measured…
Precipitation Processing System The WSR-88D system that generates 1-hour running, 3-hourly, and running storm total precipitation accumulations.
Precision The accuracy with which a number can be represented, i.e., the number of digits used to represent a number.
Predominant Wind The wind that prevails and generates the local component of the significant sea conditions across the forecast area.
preliminary data Data that have not necessarily been subjected to review, quality control and/or documentation by a responsible investigator.
Preliminary Report Now known as the "Tropical Cyclone Report". A report summarizing the life history and effects of an Atlantic or eastern Pacific tropical cyclone.
PRES Pressure
Prescribed burning Deliberate setting and careful control of surface fires in forests to help prevent more destructive fires and to kill off unwanted plants that compete…
Prescribed Fire A management ignited or natural wildland fire that burns under specified conditions where the fire is confined to a predetermined area and produces the…
Present Movement The best estimate of the movement of the center of a tropical cyclone at a given time and given position.
Present Weather The type of weather observed at the reporting time. These conditions may include types and intensity of precipitation such as light rain or heavy snow, as…
Pressure The load divided by the area over which it acts.
Pressure Altimeter An aneroid barometer calibrated to indicate altitude in feet instead of units of pressure.
Pressure Altitude The altitude in standard atmosphere at which a given pressure will be observed.
Pressure Change The net difference between the barometric pressure at the beginning and ending of a specified interval of time, usually the three hour period preceding an…
Pressure Characteristic The pattern of the pressure change during the specified period of time, usually the three hour period preceding an observation.
Pressure Couplet It is an area where you have a high pressure area located adjacent to a low pressure area.
Pressure Falling Rapidly A decrease in station pressure at a rate of 0.06 inch of mercury or more per hour which totals 0.02 inch or more.
Pressure Gage A device for registering the pressure of solids, liquids, or gases. It may be graduated to register pressure in any units desired.
Pressure Gradient The amount of pressure change occurring over a given distance.
Pressure Gradient Force A three-dimensional force vector operating in the atmosphere that accelerates air parcels away from regions of high pressure and toward regions of low…
Pressure Head The amount of force or pressure created by a depth of one foot of water.
Pressure Ice Floating sea, river, or lake ice that has been deformed, altered, or forced upward in pressure ridges by the lateral stresses of any combination of wind…
Pressure Induced Wave A rare type of wave that does not develop from wind or seismic activity. Instead, these waves develop as a pressure perturbation moves over the water…
Pressure Jump A sudden, sharp increase in atmospheric pressure, typically occurring along an active front and preceding a storm.
Pressure Rising Rapidly An increase in station pressure at a rate of 0.06 inch of mercury or more per hour which totals 0.02 inch or more.
Pressure Tendency The character and amount of atmospheric pressure change during a specified period of time, usually 3-hour period preceding an observation.
Pressure Unsteady A pressure that fluctuates by 0.03 inch of mercury or more from the mean pressure during the period of measurement.
Pressure-driven Channeling Channeling of wind in a valley by synoptic-scale pressure gradients superimposed along the valley's axis. Compare forced channeling.
Prevailing Visibility The visibility that is considered representative of conditions at the station; the greatest distance that can be seen throughout at least half the horizon…
Prevailing Westerlies The westerly winds that dominant in middle latitudes.
prevailing wind The wind direction most frequently observed during a given period.
Prevailing Winds A wind that consistently blows from one direction more than from any other.
Prevention of Significant Deterioration A program, specified in the Clean Air Act, whose goal is to prevent air quality from deteriorating significantly in areas of the country that are…
PRIM Primary
Primary Ambient Air Quality Standards Air quality standards designed to protect human health.
Primary Control Tide Station A tide station where continuous observations have been made for a minimum of 19 years.
Primary oil recovery Pumping out the crude oil that flows by gravity into the bottom of an oil well. See enhanced oil recovery, secondary oil recovery.
Primary Pollutant Substances that are pollutants immediately on entering the atmosphere. Compare secondary pollutant.
Primary Swell Direction Prevailing direction of swell propagation.
PRIN Principal
Probability The chance that an event occurs. It is usually expressed as a percent. Zero percent denotes impossibility, while 100% denotes certainty.
Probability Forecast A forecast of the probability that one or more of a mutually exclusive set of weather conditions will occur.
Probability of Hail (Abbrev. POH) - a product from the NEXRAD hail detection algorithm that estimates the likelihood that hail is present in a storm.
Probability of Precipitation (Abbrev. PoP)- The probability that precipitation will be reported at a certain location during a specified period of time.
Probability of Thunderstorms The probability based on climatology that a thunderstorm will be reported at that location during a specified period of time.
Probability of Tropical Cyclone Conditio The probability, in percent, that the cyclone center will pass within 50 miles to the right or 75 miles to the left of the listed location within the…
Problem Identification Form (PIF) (PIF) Used to identify and document problems with ARM systems, physical infrastructure, or instruments.
Product Resolution The smallest spatial increment or data element that is distinguishable in a given Doppler radar product.

Sources

National Weather Service Glossary 3,094 definitions