Subj : Wx Terms (G)(3) To : All From : Daryl Stout Date : Sun Oct 08 2017 12:05 am Grids 1) Squared off areas across the terrain used to define forecast areas. Often 5x5 or 2.5x2.5 kilometer in size. 2) Digitial forecast databases for meteorological elements, including temperature, wind direction, wind speed and others. Computer programs read these databases to create worded and graphical forecast products used by the public and others. Ground Blizzard Warning When blizzard conditions are solely caused by blowing and drifting snow. Ground Clutter A pattern of radar echoes from fixed ground targets (buildings, hills, etc.) near the radar. Ground clutter may hide or confuse precipitation echoes near the radar antenna. Also known as "anomalous propagation". Ground Fog (abbrev. GF) Fog produced over the land by the cooling of the lower atmosphere as it comes in contact with the ground. Also known as radiation fog, and in parts of California as tule fog. Ground Heat Flux The flux of heat from the ground to the earth's surface; a component of the surface energy budget. Ground receive sites In hydrologic terms, a satellite dish and associated computer which receives signals from the GOES satellite, decodes the information, and transmits it to a another site for further processing. The GOES satellite ground-receive site is located at Wallops Island, VA; and the information is relayed to a mainframe computer at NWSH for processing. Ground Stroke The current that propagates along the ground from the point where a direct stroke of lightning hits the ground. Ground Water In hydrologic terms, water within the earth that supplies wells and springs; water in the zone of saturation where all openings in rocks and soil are filled, the upper surface of which forms the water table. Also termed Phreatic water. Ground Water Divide In hydrologic terms, a line on a water table where on either side of which the water table slopes downward. It is analogous to a drainage divide between two drainage basins on a land surface. Ground Water Flow In hydrologic terms, streamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel. This is also referred to as baseflow, or dry-weather flow. Ground Water Hydrology The branch of hydrology that specializes in ground water; its occurrence and movements; its replenishment and depletion; the properties of rocks that control ground water movement and storage; and the methods of investigation and utilization of ground water. Ground Water Outflow In hydrologic terms, the part of the discharge from a drainage basin that occurs through the ground water. The term "underflow" is often used to describe the ground water outflow that takes place in valley alluvium (instead of the surface channel) and thus is not measure at a gaging station. Ground Water Overdraft Pumpage of ground water in excess of safe yield. Ground Water Runoff That part of the runoff which has passed into the ground, has become ground water, and has been discharged into a stream channel as spring, or seepage water. Grounded ice In hydrologic terms, ice that has run aground or is contact with the ground underneath it. Group Velocity The speed at which a particular wave front or swell train advances. Grout Curtain A barrier produced by injecting grout into a vertical zone, usually narrow (horizontally), and in the foundation to reduce seepage under a dam. Growing Degree Day The number of degrees that the average temperature is above a baseline value. For example, 40 degrees for canning purposes; 45 degree for potatoes; and 50 degrees for sweet corn, snap beans, lima beans, tomatoes, grapes, and field corn. Every degree that the average temperature is above the baseline value becomes a growing degree day. Agricultural related interests use growing degree days to determine planting times. Growing Season The period of time between the last killing frost of spring and the first killing frost of autumn. Growler Similar to a bergy bit, but smaller, extending less than 1 meter above the sea surface and occupying an area of 20 square meters or less. GRT great GRTST Greatest GSP On a buoy report, maximum 5-second peak gust during the measurement hour, reported at the last hourly 10-minute segment. GST On a buoy report, peak 5 or 8 second gust speed (m/s) measured during the eight-minute or two-minute period. The 5 or 8 second period can be determined by payload. GSTY Gusty GTR Greater Gulf Stream Warm water current extending from the Gulf of Mexico and Florida up the U.S. east coast then east northeast to Iceland and Norway. Gunge Slang for anything in the atmosphere that restricts visibility for storm spotting, such as fog, haze, precipitation (steady rain or drizzle), widespread low clouds (stratus), etc. Gust (Abbrev. G) - A rapid fluctuation of wind speed with variations of 10 knots or more between peaks and lulls. Gust Front The leading edge of gusty surface winds from thunderstorm downdrafts; sometimes associated with a shelf cloud or roll cloud. See also gustnado or outflow boundary. Gustnado (or Gustinado) - [Slang], gust front tornado. A small tornado, usually weak and short-lived, that occurs along the gust front of a thunderstorm. Often it is visible only as a debris cloud or dust whirl near the ground. Gustnadoes are not associated with storm-scale rotation (i.e. mesocyclones); they are more likely to be associated visually with a shelf cloud than with a wall cloud. Gyres Oceanic current systems of planetary scale driven by the global wind system. --- þ Synchronet þ The Thunderbolt BBS - wx1der.dyndns.org .