Weather Glossary – N


NCEP – National Centers for Environmental Prediction. Central computer and communications facility of the National Weather Service; located in Washington, DC.

NEGATIVE TILTED TROUGH– A trough which tilts from the northwest toward the southeast. This situation creates instability since cold temperatures in the mid and upper levels advect over warmer air at the surface. A negative tilt is a sign a trough is mature.

NEXRAD – NEXt Generation RADar. A NWS network of about 140 Doppler radars operating nationwide.

NGM -Nested Grid Model generated every 12 hours by NCEP.

NHC -National Hurricane Center. The office of the National Weather Service in Miami that is responsible for tracking and forecasting tropical cyclones.

NOAA – National Oceanic and Atmospheric Administration. A branch of the US Department of Commerce, NOAA is the parent organization of the National Weather Service.

NOAA WEATHER RADIO (NWR)- Continuous, 24 hour-a-day VHF broadcasts of weather observations and forecasts directly from National Weather Service offices. A special tone allows certain receivers to alarm when watches or warnings are issued.

NOAA WEATHER WIRE (NWWS) – Mass dissemination via satellite of National Weather Service products to the media and public.

NUMERICAL WEATHER PREDICTION (NWP) – Forecasting weather by the use of numerical models, run on high speed computers. Most of the NWP for the National Weather Service is done at the National Centers for Environmental Prediction (NCEP).

NUMEROUS – Showers covering more than 54 percent of an area.

NWS – National Weather Service.