Subj : Wx Terms (N)(2) To : All From : Daryl Stout Date : Sat Jul 15 2017 12:06 am NDFD (National Digital Forecast Database) - The National Weather Service's NDFD provides access to gridded forecasts of sensible weather elements (e.g., wind, wave height) through the National Digital Forecast Database (NDFD). NDFD contains a seamless mosaic of digital forecasts from NWS field offices working in collaboration with the National Centers for Environmental Prediction (NCEP). The database is made available to all customers and partners from the public, private and academic sectors. Those customers and partners may use this data to create a wide range of text, graphic, gridded and image products of their own. NE Northeast Neap Tide A minimum tide occurring at the first and third quarters of the moon. Nearshore Forecast (NSH) - National Weather Service seasonal marine forecasts for an area of the Great Lakes extending from a line approximating mean low water datum along the coast or an island, including bays, harbors, and sounds, out to 5 nm. These forecasts are normally issued from Daylight Savings Time approximately April 7 through December 31, though the dates may be shortened or extended based on local/regional requirements. NEC Necessary NEG Negative Negative Vorticity Advection (Abbrev. NVA) - the advection of lower values of vorticity into an area. Negative-tilt Trough An upper level system which is tilted to the west with increasing latitude (i.e., with an axis from southeast to northwest). A negative-tilt trough often is a sign of a developing or intensifying system. NELY Northeasterly NERN Northeastern NESDIS National Environmental Satellite, Data, and Information Service. NESDIS collects, processes, stores, analyzes, and disseminates various types of hydrologic, meteorologic, and oceanic data. NESDIS is also responsible for the development of analytical and descriptive products so as to meet the needs of its users. Net All-Wave Radiation The net or resultant value of the upward and downward longwave and shortwave radiative fluxes through a plane at the earth-atmosphere interface; a component of the surface energy budget. Net Rainfall In hydrologic terms, the portion of rainfall which reaches a stream channel or the concentration point as direct surface flow. Neutral Line The line that separates longitudinal magnetic fields of opposite polarity. Neutral Stability An atmospheric condition that exists in unsaturated air when the environmental lapse rate equals the dry adiabatic rate, or in saturated air when the environmental lapse rate equals the moist adiabatic rate. NEWD Northeastward NEXRAD NEXt Generation RADar. A NWS network of about 140 Doppler radars operating nationwide. NGM The Nested Grid Model, a 48-hour numerical model of the atmosphere run twice daily by NCEP. NGT Night NHC National Hurricane Center - one of three branches of the Tropical Prediction Center (TPC). This center maintains a continuous watch on tropical cyclones over the Atlantic, Caribbean, Gulf of Mexico, and the Eastern Pacific from 15 May through November 30. The Center prepares and distributes hurricane watches and warnings for the general public, and also prepares and distributes marine and military advisories for other users. During the "off-season" NHC provides training for U.S. emergency managers and representatives from many other countries that are affected by tropical cyclones. NHC also conducts applied research to evaluate and improve hurricane forecasting techniques, and is involved in public awareness programs. NHOP (National Hurricane Operations Plan) - The NHOP is issued annually by the Federal Coordinator for Meteorological Services and Supporting Research. It documents interdepartmental agreements relating to tropical cyclone observing, warning, and forecasting services. National Hurricane Center (NHC), Central Pacific Hurricane Center (CPHC), and the JTWC serve as the principal offices in coordinating the day-to-day activities of the NWS in support of the Plan in their region of responsibility. Nieve Penitente A spike or pillar of compacted snow, firn or glacier ice, caused by differential melting and evaporation. The pillars form most frequently on low-latitude mountains where air temperatures are near freezing, dew points are much below freezing and insolation is strong. Penitents are oriented individually toward the noon-day sun, and usually occur in east-west lines. Night The period of the day between dusk and dawn. NIL None Nimbostratus (abbrev. NS)- A cloud of the class characterized by a formless layer that is almost uniformly dark gray; a rain cloud of the layer type, of low altitude, usually below 8000 ft (2400 m). NLY Northerly NM Nautical Miles NMBR Number NMC National Meteorological Center NML Normal NMRS Numerous NOAA National Oceanic and Atmospheric Administration NOAA Weather Radio "The voice of the National Weather Service" - NOAA Weather Radio broadcasts National Weather Service warnings, watches, forecasts and other hazard information 24 hours a day. It is provided as a public service by NOAA. The NOAA Weather Radio network has more than 480 stations in the 50 states and near adjacent coastal waters, Puerto Rico, the U.S. Virgin Islands and U.S. Pacific Territories. It operates between 162.40 and 162.55 Megahertz on the Public Service Band. NOAA Weather Wire Mass dissemination via satellite of National Weather Service products to the media and public. Noctilucent Clouds Wavy, thin, bluish-white clouds that are best seen at twilight in polar latitudes. They form at altitudes about 80 to 90 km above the Earth's surface. Nocturnal Related to nighttime; occurring at night. Nocturnal Inversion Used interchangably with Radiational Inversion; a temperature inversion that develops during the night as a result of radiational cooling of the surface. Because the immediate surface (lower Boundary Layer) cools much more rapidly during radiational cooling conditions than the air just above (upper Boundary Layer), a temperature inversion can be created overnight, but typically erodes quickly after sunrise. Nocturnal Jet This wind speed maximum occurs just above the nocturnal inversion at night. It is typically found in the south central United States during the late spring and summer months. It is important in the development of Mesoscale Convective Complexes (MCC) or Mesoscale Convective Systems (MCS). Nocturnal Thunderstorms Thunderstorms which develop after sunset. They are often associated with the strengthening of the low level jet and are most common over the Plains states. They also occur over warm water and may be associated with the seaward extent of the overnight land breeze. NOGAPS Navy Operational Global Atmospheric Prediction System; a 144-hour numerical model of the atmosphere run by the U.S. Navy twice daily. NOHRSC In hydrologic terms, the National Operational Hydrologic Remote Sensing Center. An organization under the National Weather Service Office of Hydrology (OH) that mainly deals with snow mapping. --- þ Synchronet þ The Thunderbolt BBS - wx1der.dyndns.org .