Definition
A National Weather Service product that provides a seamless, gridded set of digital forecasts of weather elements (such as cloud cover, wind, temperature, and precipitation) covering the contiguous United States and surrounding areas. The NDFD supplies the underlying forecast data used to generate Significant Weather Prognostic Charts and other graphical aviation weather products.
Plain English
It is a national database of computer-generated weather forecasts, broken down into a fine grid of points across the country. Each grid point holds the forecast values for things like wind, temperature, and clouds, and these forecasts are what get turned into the weather charts pilots use.
Context Anchor
Seen in aviation weather discussions, especially when learning how significant weather prognostic charts are created and what forecast data they are based on.
Derivation
‘Digital’ here means the forecasts are stored as numerical values on a grid rather than as written text or hand-drawn charts. ‘Database’ means a structured collection of those values that other tools can pull from to build charts and products.
Why Pilots Care
It supplies the forecast data that underlies many of the weather products pilots consult before flight.
Intuition Check
Do not think of NDFD as one specific chart. It is the forecast database that can supply information used to make charts and other weather products.
Example Sentence 1
The Significant Weather Prognostic Chart is generated from forecast data contained in the NDFD.
Example Sentence 2
NDFD data feeds the significant weather prognostic charts shown during the weather briefing.