The verification of HPC grids is based on point forecasts. HPC is not actually verifying the 5-km grids since we do not have access to a gridded verification field. Instead we are verifying the 384 HPC point forecasts that are used to produce the gridded forecasts. At each point, the forecast values are verified using observations at that point.

For comparison, we use a similar methodology to verify MOS forecasts and NDFD grids. MOS values at the 384 points are verified directly with observations. To verify the NDFD grids, HPC interpolates point forecasts from the NDFD to the same 384 points and compares them to the same observations used to verify MOS and HPC point forecasts.

If you have any questions about this verification process, please contact Edwin.Danaher@noaa.gov.