World Meteorological Organization GRIB (GRIdded Binary) Reader

Licensing options for this format begin with FME Desktop Professional Edition.

The World Meteorological Organization GRIB (GRIdded Binary) Reader allows FME to access data in the GRIB format.


GRIB is a file format designed by the World Meteorological Organization (WMO) for storing and transmitting gridded meteorological data, such as Numerical Weather Prediction model output.

One GRIB file may contain multiple “messages,” each of which records a particular variable at a particular time (for example, temperature, pressure, precipitation, wind speed, etc.). FME generates a single raster feature per GRIB file, where each message is represented as a band.

Three editions of GRIB have been issued by the WMO. FME supports reading GRIB Edition 1 and GRIB Edition 2. GRIB Edition 0 is obsolete and not supported by FME.

Note the following known limitations of the GRIB reader:

  • The GRIB format supports up to two Nodata values per band. FME will honor the first Nodata value from the first band, and apply this to all bands on the raster.
  • Different messages in a GRIB file may have different dimensions. However, since messages are treated as bands, the dimensions and location of all messages will be forced to match those of the first message.
  • Irregular grids (that is, grids that have a different number of cells per row) cannot be read.

Reader Overview

FME considers a single GRIB file to be a dataset. Each dataset contains a single FME raster feature.

FME Raster Features

FME raster features represent raster data and use several concepts that are unlike those used in the handling of vector data. The topics below describe how FME processes raster data.

About FME Rasters Tiling and Mosaicking
Raster Properties Band Combining and Separating
Band Properties Band and Palette Selection
Palette Properties Raster Processing
Compression Raster versus Vector Features
Pyramiding Raster File Naming
Interleaving World Files
Interpretation and Data Type TAB Files
Palette Resolution  

GRIB supports rasters with an arbitrary number of Real64 bands.