Subj : Wx Terms (S)(8) To : All From : Daryl Stout Date : Thu Jul 20 2017 12:05 am Station Model A specified pattern for plotting, on a weather map, the meteorological symbols that represent the state of the weather at a particular observing station. Station Pressure The absolute air pressure at a given reporting station. The air pressure is directly proportional to the combined weight of all air in the atmosphere located in a column directly above the reporting site. Consequently, the station pressure may vary tremendously from one location to another in mountainous regions due to the strong variation of atmospheric pressure with height. Vertical variations of pressure range up to 150 mb per mile whereas horizontal variations are usually less than ..1 mb per mile. Stationary Front A front between warm and cold air masses that is moving very slowly or not at all. STBL Stable Steam Fog Fog formed when water vapor is added to air which is much colder than the source of the vapor. It may be formed when very cold air drifts across relatively warm water. At temperatures below about -20øF, ice particles or droxtals may be formed in the air producing a type of ice fog known as frost smoke. Steepness In marine terms, on a buoy report, wave steepness is the ratio of wave height to wave length and is an indicator of wave stability. When wave steepness exceeds a 1/7 ratio, the wave becomes unstable and begins to break. Steering Currents Same as Steering Winds; a prevailing synoptic scale flow which governs the movement of smaller features embedded within it. Steering Winds Same as Steering Currents; A prevailing synoptic scale flow which governs the movement of smaller features embedded within it. Stepped Leader A faint, negatively charged channel that emerges from the base of a thunderstorm and propagates toward the ground in a series of steps of about 1 microsecond duration and 50-100 meters in length, initiating a lightning stroke. STFR Stratus Fractus STG Strong Stilling basin In hydrologic terms, a basin constructed to dissipate the energy of fast-flowing water (e.g., from a spillway or bottom outlet), and to protect the streambed from erosion. STJ Subtropical Jet - this jet stream is usually found between 20ø and 30ø latitude at altitudes between 12 and 14 km. STLT Satellite STM Stratiform STNRY Stationary Stoplogs In hydrologic terms, large logs, timbers or steel beams placed on top of each other with their ends held in guides on each side of a channel or conduit providing a temporary closure versus a permanent bulkhead gate. Storm Any disturbed state of the atmosphere, especially affecting the Earth's surface, and strongly implying destructive and otherwise unpleasant weather. Storms range in scale from tornadoes and thunderstorms to tropical cyclones to synoptic-scale extratropical cyclones. Storm Data This National Climatic Data Center (NCDC) monthly publication documents a chronological listing, by states, of occurrences of storms and unusual weather phenomena. Reports contain information on storm paths, deaths, injuries, and property damage. An "Outstanding storms of the month" section highlights severe weather events with photographs, illustrations, and narratives. The December issue includes annual tornado, lightning, flash flood, and tropical cyclone summaries. Storm Motion The speed and direction at which a thunderstorm travels. Storm Relative Measured relative to a moving thunderstorm, usually referring to winds, wind shear, or helicity. Storm Relative Mean Radial Velocity Map (SRM): This WSR-88D radar product depicts a full 360ø sweep of radial velocity data with the average motion of all identified storms subtracted out. It is available for every elevation angle sampled. It is used to aid in displaying shear and rotation in storms and storm top divergence that might otherwise be obscured by the storm's motion, investigate the 3-D velocity structure of a storm, and help with determining rotational features in fast and uniform moving storms. Storm Relative Mean Radial Velocity Region (SRR): This WSR-88D radar product depicts a 27 nm by 27 nm region of storm relative mean radial velocity centered on a point which the operator can specify anywhere within a 124 nm radius of the radar. The storm motion subtracted defaults to the motion of the storm closest to the product center, or can be input by the operator. It is used to examine the 3-dimensional storm relative flow of a specific thunderstorm (radar operator centers product on a specific thunderstorm; aid in displaying shear and rotation in thunderstorms and storm top divergence that might otherwise be obscured by storm motion; and gain higher resolution velocity product. Storm Scale Referring to weather systems with sizes on the order of individual thunderstorms. See synoptic scale and mesoscale. Storm Surge An abnormal rise in sea level accompanying a hurricane or other intense storm, 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 tide from the observed storm tide. Storm Tide The actual level of sea water resulting from the astronomic tide combined with the storm surge. Most NWS flood statements, watches, or warnings quantifying above-normal tides will report the Storm Tide. Storm Total Precipitation This radar image is an estimate of accumulated rainfall since the last time there was a one-hour, or more, break in precipitation. It is used to locate flood potential over urban or rural areas, estimate total basin runoff and provide rainfall accumulations for the duration of the event and is available only for the short range (out to 124 nm). To determine accumulated precipitation at greater distances you should link to an adjacent radar. Storm Tracking Information This WSR-88D radar product displays the previous, current, and projected locations of storm centroids (forecast and past positions are limited to one hour or less). Forecast tracks are based upon linear extrapolation of past storm centroid positions, and they are intended for application to individual thunderstorms not lines or clusters. It is used to provide storm movement: low track variance and/or 2 or more plotted past positions signify reliable thunderstorm movement. Storm Warning A warning of sustained surface winds, or frequent gusts, in the range of 48 knots (55 mph) to 63 knots (73 mph) inclusive, either predicted or occurring, and not directly associated with a tropical cyclone. Stormwater Discharge In hydrologic terms, precipitation that does not infiltrate into the ground or evaporate due to impervious land surfaces but instead flows onto adjacent land or water areas and is routed into drain/sewer systems. Straight-Line Hodograph The name pretty well describes what it looks like on the hodograph. What causes this shape is a steady increase of winds with height (vertical wind shear). This shape of hodograph favors multicell thunderstorms. Straight-line Winds Generally, any wind that is not associated with rotation, used mainly to differentiate them from tornadic winds. Stratiform Having extensive horizontal development, as opposed to the more vertical development characteristic of convection. Stratiform clouds cover large areas but show relatively little vertical development. Stratiform precipitation, in general, is relatively continuous and uniform in intensity (i.e., steady rain versus rain showers). Stratiform Rings and Bands These occur between the active convective bands of a hurricane outside of the eye wall. Inner stratiform bands often exhibit the bright band aloft, a VIP Level 2, and in the lower layers typically show a VIP Level 1. Stratocumulus Low-level clouds, existing in a relatively flat layer but having individual elements. Elements often are arranged in rows, bands, or waves. Stratocumulus often reveals the depth of the moist air at low levels, while the speed of the cloud elements can reveal the strength of the low-level jet. Stratopause The boundary between the stratosphere and mesosphere. Stratosphere The region of the atmosphere extending from the top of the troposphere to the base of the mesosphere, an important area for monitoring stratospheric ozone. --- þ Synchronet þ The Thunderbolt BBS - wx1der.dyndns.org .