Glossary - S |
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S Saffir-Simpson Hurricane Wind Scale
The Saffir-Simpson Hurricane Wind Scale is a 1 to 5 categorization based on the intensity of the hurricane at the indicated time. The scale provides examples of the type of damage and impacts in the United States associated with winds of the indicated intensity. A detailed description of the Saffir-Simpson Hurricane Wind Scale, which was revised in early 2010, is available at http://www.nhc.noaa.gov/sshws.shtml. Source: NOAA-NHC.
salinity
The amount of chemical salts (compounds that include Na, K, Mg, Ca) contained in a solution. Source: US NPS
salt burn
When the roots of the plant come in contact with more salt in the soil then they can cope with.
salt spray
Spray of salt or salt water that forms when ocean waves crash.
Sargasso Sea
The region (actually in the horse latitudes) of the North Atlantic Ocean to the east and south of the Gulf Stream system. This is a region of convergence of the surface waters, and is characterized by clear, warm water, a deep blue color, and large quantities of floating sargassum or “gulf weed.” Source: (c) 1999, American Meteorological Society. Used with permission.
satellite
A man-made device orbiting around the earth, moon, or another planet. Satellites are used for research, communications, weather information, and navigation.
saturation
In meteorological terms, a condition in which air at a specific temperature contains all the water vapor it can hold. At this point, the air cannot absorb any more water vapor, and additional amounts of the vapor will appear as precipitation.
scattering
The spreading of waves, such as light, over a range of directions as a result of encountering a rough boundary (water) or collisions with particles.
sea level
The average height of the ocean.
sea level pressure
The atmospheric pressure at sea level at a given location. Once calculated, horizontal variations of sea level pressure may be compared for location of high and low pressure areas and fronts.
Sea Surface Temperature (SST)
The term refers to the mean temperature of the ocean in the upper few meters. Source: NOAA-NWS
SHIFOR
Statistical Hurricane Intensity Forecast, a type of statistical model. Source: HSS
SHIPS
Statistical Hurricane Intensity Prediction Scheme, a type of statistical-dynamical model. Source: HSSM
SLOSH
Sea, Lake, and Overland Surges by Hurricanes, a computer model used by the National Hurricane Center to estimate storm surge heights and winds resulting from historical, hypothetical, or predicted hurricanes by taking into account pressure, size, forward speed, track, and winds. Source: NOAA (See www.nhc.noaa.gov/HAW2/english/surge/slosh.shtml, Jelesnianski et al., 1992)
Southern Oscillation (SO)
A "see-saw" in surface pressure in the tropical Pacific characterized by simultaneously opposite sea level pressure anomalies at Tahiti, in the eastern tropical Pacific and Darwin, on the northwest coast of Australia. The SO was discovered by Sir Gilbert Walker in the early 1920s. Walker was among the first meteorologists to use the statistical techniques to analyze and predict meteorological phenomena. Later, the three-dimensional east-west circulation related to the SO was discovered and named the "Walker Circulation". The SO oscillates with a period of 2-5 years. During one phase, when the sea level pressure is low at Tahiti and High at Darwin, the El Niño occurs. The cold phase of the SO, called La Niña, is characterized by high pressure in the eastern equatorial Pacific, low in the west, and by anomalously cold sea surface temperature (SST) in the central and eastern Pacific. This is called El Niño Southern Oscillation or ENSO. Source: NOAA Jetstream
Southern Oscillation Index (SOI)
A numerical index measuring the state of the Southern Oscillation. The SOI is based on the (atmospheric) pressure difference between Tahiti and Darwin, Australia. It is highly correlated with tropical sea surface temperature anomaly indices recorded in El Nino/La Nina.
spiral rain bands
Bands of thunderstorms and intense rain that wrap around a hurricane. Source: Canadian Hurricane Centre
statistical models
Are based on historical relationships between hurricane-specific information, such as the location and time of year, and the behavior of historical hurricanes. These models are much simpler than dynamical models, and they can produce a computer-generated forecast much more quickly, often within seconds. Source: HSS
statistical-dynamical models
Statistical-dynamical models blend both dynamical and statistical techniques by making a forecast based on established historical relationships between storm behavior and atmospheric variables provided by dynamical models. Source: HSS
steady state
A stable condition where a system has numerous properties that are unchanging in time, or in which a change in one direction is continuously balanced by a change in another direction.
steering flow
(Or steering current) A prevailing synoptic scale flow which governs the movement of smaller features embedded within it. Source: NOAA-NWS
storm surge
An abnormal rise in sea level accompanying a hurricane or other intense storm, and whose height is the difference between the observed level of the sea surface and the level that would have occurred in the absence of the cyclone. Storm surge is usually estimated by subtracting the normal or astronomic high tide from the observed storm tide. Source NOAA-NHC.
storm surge warning system
A warning that significant wind-forced flooding is to be expected along low-lying coastal areas if weather patterns develop as forecast.
storm tide
The actual sea level resulting from astronomical tide combined with the storm surge. This term is used interchangeably with hurricane tide. Source: NOAA-NWS SRH
storm warning
A warning of 1-minute sustained surface winds of 88 km/h (55 mph) or greater, either predicted or occurring, not directly associated with tropical cyclones. Source NOAA-NHC.
stratosphere
The second major layer of the atmosphere of the Earth, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down.
strike
For any particular location, a hurricane strike occurs if that location passes within the strike circle of the hurricane, a circle of 230 km (144 mi) diameter, centered 23 km (14 mi) to the right of the hurricane center (looking in the direction of motion). This circle is meant to depict the typical extent of hurricane force winds, which are approximately 139 km (86 mi) to the right of the center and 93 km (57 mi) to the left. Source NOAA-NHC.
subtropical depression
A subtropical cyclone in which the maximum sustained surface wind speed (using the U.S. 1-minute average) is 33 kt (38 mph or 62 km/hr) or less. Source NOAA-NHC.
subtropical ridge
One of the two bands of high atmospheric pressure that are centered near 30°N and 30°S latitudes.
subtropical storm
A non-frontal low pressure system that has characteristics of both tropical and extratropical cyclones. This system is typically an upper-level cold low with circulation extending to the surface layer and maximum sustained winds generally occurring at a radius of about 100 miles or more from the center. In comparison to tropical cyclones, such systems have a relatively broad zone of maximum winds that is located farther from the center, and typically have a less symmetric wind field and distribution of convection. Source: NOAA-NHC.
subtropical storm
A subtropical cyclone in which the maximum sustained surface wind speed (using the U.S. 1-minute average) is 63 km/h (39 mph) or more. Source NOAA-NHC.
synoptic track
Weather reconnaissance mission flown to provide vital meteorological information in data sparse ocean areas as a supplement to existing surface, radar, and satellite data. Synoptic flights better define the upper atmosphere and aid in the prediction of tropical cyclone development and movement. Source NOAA-NHC.
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