NARCCAP data is CF-compliant, and therefore can be imported directly into ArcGIS v.9.3 or higher. There are two ways to import NetCDF data: as a feature layer, or as a raster layer.

Importing NetCDF as Raster

1. Download data.
2. Start ArcMap.
3. Before importing NetCDF data, add a layer that defines a map projection, or ArcMap will be unable to reproject the raster data to match other layers. (This is a workaround; the problem is being looked into.)
4. Under ArcToolbox -> Multidimension Tools, choose "Make NetCDF Raster Layer".
5. A dialog will appear. Select your datafile as the "Input netCDF File". (Depending on the size of the file, you may now need to wait some time while ArcMap reads metadata from the file.)
6. Choose the data variable using the "Variables" drop-down.
7. Optional: choose a timestep using the "Dimension Values" portion of the dialog. (By default, ArcGIS only reads the first timestep in the file.) Note that while you can subset the time dimension this way, you will likely find it easier and get better performance using other tools such as NCO to process the NetCDF files to condense or extract data of interest before importing it into GIS.
8. Click "OK".

Importing NetCDF as Feature

1. Download data.
2. Start ArcMap.
3. Under ArcToolbox -> Multidimension Tools, choose "Make NetCDF Feature Layer".
4. A dialog will appear. Select your datafile as the "Input netCDF File". (Depending on the size of the file, you may now need to wait some time while ArcMap reads metadata from the file.).
5. Choose the data variable using the "Variables" drop-down.
6. Change the X Variable and Y Variable to "lon" and "lat", respectively, using the appropriate drop-downs.
7. Add xc and yc under "Row Dimensions".
8. Optional: choose a timestep using the "Dimension Values" portion of the dialog. (See above for more details.)
9. Click "OK".

Note that by default each data point is drawn using the same symbol. To apply a color ramp to the points, right-click the layer name and choose Properties, click the Symbology tab, and choose Quantities->Graduated Colors.