To netCDF-Java and TDS users:
We have discovered that our GRIB reading software is not correctly
reading GRIB variables whose time coordinates are time intervals, rather
than instantaneous time. This affects both clients that use the
netCDF-Java library, and TDS servers, which read GRIB1 or GRIB2 files.
If you are not reading GRIB files, then this problem will not affect you.
In the real-time NCEP model output datasets that we serve on motherlode,
this problem occurs with about 20% of the variables. A list of the
problem variables follows. In almost all cases, the data itself is
correctly read, but the metadata describing the time coordinate is
misleading. However, the RUC2_CONUS_20km_pressure dataset has
inconsistent results for the variables "Convective_precipitation" and
"Large_scale_precipitation".
"Time interval coordinates" have a start and ending time, and a
"statistical type" like Accumulation, Average, Maximum, etc. which is
applied over the time range. We have been inadvertently ignoring time
interval coordinates and their statistical type, and instead presenting
these variables as if they were instantaneous. The Common Data Model has
a way to represent interval coordinates using the CF Conventions
"bounds" attribute on the time coordinate, which points to a variable
containing the starting and ending time coordinate for that interval. We
will be modifying the GRIB IOSP to do that.
We will be putting out a new release of version 4.2 of the netCDF-Java
library and the TDS that fixes this problem ASAP. This problem will not
be fixed in version 4.1, however. If you have been using these datasets
in a way that will be affected by these changes, or have concerns or
questions about these fixes, please respond to this email group or
privately to support-netcdf-java@xxxxxxxxxxxxxxxx.
Sorry for the trouble,
John Caron
========================================================
GRIB2 datasets with variables that are affected. The number in () is the
grid definition template number.
Q:\cdmUnitTest\tds\new\DGEX_Alaska_12km_20100524_0000.grib2
Total_precipitation/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\DGEX_CONUS_12km_20100514_1800.grib2
Total_precipitation/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\GEFS_Global_1p0deg_Ensemble_20100424_0000.grib2
Categorical_Freezing_Rain/Ground or water surface (11)
Categorical_Ice_Pellets/Ground or water surface (11)
Categorical_Rain/Ground or water surface (11)
Categorical_Snow/Ground or water surface (11)
Downward_long_wave_rad_flux/Ground or water surface (11)
Downward_short_wave_rad_flux/Ground or water surface (11)
Latent_heat_net_flux/Ground or water surface (11)
Maximum_temperature/Specified height level above ground (11)
Minimum_temperature/Specified height level above ground (11)
Sensible_heat_net_flux/Ground or water surface (11)
Total_cloud_cover/Entire atmosphere layer (11)
Total_precipitation/Ground or water surface (11)
Upward_long_wave_rad_flux/Ground or water surface (11)
Upward_long_wave_rad_flux/Nominal top of the atmosphere (11)
Upward_short_wave_rad_flux/Ground or water surface (11)
Q:\cdmUnitTest\tds\new\GEFS_Global_1p0deg_Ensemble_derived_20100423_0000.grib2
Categorical_Freezing_Rain/Ground or water surface (12)
Categorical_Ice_Pellets/Ground or water surface (12)
Categorical_Rain/Ground or water surface (12)
Categorical_Snow/Ground or water surface (12)
Downward_long_wave_rad_flux/Ground or water surface (12)
Downward_short_wave_rad_flux/Ground or water surface (12)
Latent_heat_net_flux/Ground or water surface (12)
Maximum_temperature/Specified height level above ground (12)
Minimum_temperature/Specified height level above ground (12)
Sensible_heat_net_flux/Ground or water surface (12)
Total_cloud_cover/Entire atmosphere layer (12)
Total_precipitation/Ground or water surface (12)
Upward_long_wave_rad_flux/Ground or water surface (12)
Upward_long_wave_rad_flux/Nominal top of the atmosphere (12)
Upward_short_wave_rad_flux/Ground or water surface (12)
Q:\cdmUnitTest\tds\new\GFS_Global_0p5deg_20100602_0000.grib2
Albedo/Ground or water surface (8)
Categorical_Freezing_Rain/Ground or water surface (8)
Categorical_Ice_Pellets/Ground or water surface (8)
Categorical_Rain/Ground or water surface (8)
Categorical_Snow/Ground or water surface (8)
Cloud_Work_Function/Entire atmosphere layer (8)
Convective_Precipitation_Rate/Ground or water surface (8)
Convective_precipitation/Ground or water surface (8)
Downward_long_wave_rad_flux/Ground or water surface (8)
Downward_short_wave_rad_flux/Ground or water surface (8)
Ground_Heat_Flux/Ground or water surface (8)
Latent_heat_net_flux/Ground or water surface (8)
Maximum_temperature/Specified height level above ground (8)
Meridional_Flux_of_Gravity_Wave_Stress/Ground or water surface (8)
Minimum_temperature/Specified height level above ground (8)
Momentum_flux_u_component/Ground or water surface (8)
Momentum_flux_v_component/Ground or water surface (8)
Precipitation_rate/Ground or water surface (8)
Pressure/High cloud bottom level (8)
Pressure/High cloud top level (8)
Pressure/Low cloud bottom level (8)
Pressure/Low cloud top level (8)
Pressure/Middle cloud bottom level (8)
Pressure/Middle cloud top level (8)
Sensible_heat_net_flux/Ground or water surface (8)
Temperature/High cloud top level (8)
Temperature/Low cloud top level (8)
Temperature/Middle cloud top level (8)
Total_cloud_cover/Boundary layer cloud layer (8)
Total_cloud_cover/Entire atmosphere layer (8)
Total_cloud_cover/High cloud layer (8)
Total_cloud_cover/Low cloud layer (8)
Total_cloud_cover/Middle cloud layer (8)
Total_precipitation/Ground or water surface (8)
Upward_long_wave_rad_flux/Ground or water surface (8)
Upward_long_wave_rad_flux/Nominal top of the atmosphere (8)
Upward_short_wave_rad_flux/Ground or water surface (8)
Upward_short_wave_rad_flux/Nominal top of the atmosphere (8)
Water_runoff/Ground or water surface (8)
Zonal_Flux_of_Gravity_Wave_Stress/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\GFS_Global_2p5deg_20100602_1200.grib2
Albedo/Ground or water surface (8)
Categorical_Freezing_Rain/Ground or water surface (8)
Categorical_Ice_Pellets/Ground or water surface (8)
Categorical_Rain/Ground or water surface (8)
Categorical_Snow/Ground or water surface (8)
Cloud_Work_Function/Entire atmosphere layer (8)
Convective_Precipitation_Rate/Ground or water surface (8)
Convective_precipitation/Ground or water surface (8)
Downward_long_wave_rad_flux/Ground or water surface (8)
Downward_short_wave_rad_flux/Ground or water surface (8)
Ground_Heat_Flux/Ground or water surface (8)
Latent_heat_net_flux/Ground or water surface (8)
Maximum_temperature/Specified height level above ground (8)
Meridional_Flux_of_Gravity_Wave_Stress/Ground or water surface (8)
Minimum_temperature/Specified height level above ground (8)
Momentum_flux_u_component/Ground or water surface (8)
Momentum_flux_v_component/Ground or water surface (8)
Precipitation_rate/Ground or water surface (8)
Pressure/High cloud bottom level (8)
Pressure/High cloud top level (8)
Pressure/Low cloud bottom level (8)
Pressure/Low cloud top level (8)
Pressure/Middle cloud bottom level (8)
Pressure/Middle cloud top level (8)
Sensible_heat_net_flux/Ground or water surface (8)
Temperature/High cloud top level (8)
Temperature/Low cloud top level (8)
Temperature/Middle cloud top level (8)
Total_cloud_cover/Boundary layer cloud layer (8)
Total_cloud_cover/Entire atmosphere layer (8)
Total_cloud_cover/High cloud layer (8)
Total_cloud_cover/Low cloud layer (8)
Total_cloud_cover/Middle cloud layer (8)
Total_precipitation/Ground or water surface (8)
Upward_long_wave_rad_flux/Ground or water surface (8)
Upward_long_wave_rad_flux/Nominal top of the atmosphere (8)
Upward_short_wave_rad_flux/Ground or water surface (8)
Upward_short_wave_rad_flux/Nominal top of the atmosphere (8)
Water_runoff/Ground or water surface (8)
Zonal_Flux_of_Gravity_Wave_Stress/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\GFS_Global_onedeg_20100529_0600.grib2
Albedo/Ground or water surface (8)
Categorical_Freezing_Rain/Ground or water surface (8)
Categorical_Ice_Pellets/Ground or water surface (8)
Categorical_Rain/Ground or water surface (8)
Categorical_Snow/Ground or water surface (8)
Cloud_Work_Function/Entire atmosphere layer (8)
Convective_Precipitation_Rate/Ground or water surface (8)
Convective_precipitation/Ground or water surface (8)
Downward_long_wave_rad_flux/Ground or water surface (8)
Downward_short_wave_rad_flux/Ground or water surface (8)
Ground_Heat_Flux/Ground or water surface (8)
Latent_heat_net_flux/Ground or water surface (8)
Maximum_temperature/Specified height level above ground (8)
Meridional_Flux_of_Gravity_Wave_Stress/Ground or water surface (8)
Minimum_temperature/Specified height level above ground (8)
Momentum_flux_u_component/Ground or water surface (8)
Momentum_flux_v_component/Ground or water surface (8)
Precipitation_rate/Ground or water surface (8)
Pressure/High cloud bottom level (8)
Pressure/High cloud top level (8)
Pressure/Low cloud bottom level (8)
Pressure/Low cloud top level (8)
Pressure/Middle cloud bottom level (8)
Pressure/Middle cloud top level (8)
Sensible_heat_net_flux/Ground or water surface (8)
Temperature/High cloud top level (8)
Temperature/Low cloud top level (8)
Temperature/Middle cloud top level (8)
Total_cloud_cover/Boundary layer cloud layer (8)
Total_cloud_cover/Entire atmosphere layer (8)
Total_cloud_cover/High cloud layer (8)
Total_cloud_cover/Low cloud layer (8)
Total_cloud_cover/Middle cloud layer (8)
Total_precipitation/Ground or water surface (8)
Upward_long_wave_rad_flux/Ground or water surface (8)
Upward_long_wave_rad_flux/Nominal top of the atmosphere (8)
Upward_short_wave_rad_flux/Ground or water surface (8)
Upward_short_wave_rad_flux/Nominal top of the atmosphere (8)
Water_runoff/Ground or water surface (8)
Zonal_Flux_of_Gravity_Wave_Stress/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\NAM_Alaska_11km_20100519_0000.grib2
Convective_precipitation/Ground or water surface (8)
Probability_of_freezing_precipitation/Ground or water surface (8)
Probability_of_frozen_precipitation/Ground or water surface (8)
Probability_of_p01_inch_precipitation/Ground or water surface (8)
Thunderstorm_probability/Ground or water surface (8)
Total_precipitation/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\NAM_Alaska_45km_conduit_20100524_0000.grib2
Baseflow_groundwater_runoff/Ground or water surface (8)
Convective_precipitation/Ground or water surface (8)
Downward_long_wave_rad_flux/Ground or water surface (8)
Downward_short_wave_rad_flux/Ground or water surface (8)
Evaporation/Ground or water surface (8)
Ground_Heat_Flux/Ground or water surface (8)
Large_scale_precipitation/Ground or water surface (8)
Latent_heat_net_flux/Ground or water surface (8)
Potential_Evaporation/Ground or water surface (8)
Sensible_heat_net_flux/Ground or water surface (8)
Snow_melt/Ground or water surface (8)
Snow_phase_change_heat_flux/Ground or water surface (8)
Storm_surface_runoff/Ground or water surface (8)
Total_cloud_cover/Entire atmosphere layer (8)
Total_precipitation/Ground or water surface (8)
Upward_long_wave_rad_flux/Ground or water surface (8)
Upward_long_wave_rad_flux/Nominal top of the atmosphere (8)
Upward_short_wave_rad_flux/Ground or water surface (8)
Upward_short_wave_rad_flux/Nominal top of the atmosphere (8)
Water_equivalent_of_accumulated_snow_depth/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\NAM_CONUS_12km_20100425_1800.grib2
Baseflow_groundwater_runoff/Ground or water surface (8)
Convective_precipitation/Ground or water surface (8)
Deep_convective_heat_rate/Entire atmosphere layer (8)
Downward_short_wave_rad_flux/Ground or water surface (8)
Large_scale_condensate_heat_rate/Entire atmosphere layer (8)
Snow_melt/Ground or water surface (8)
Storm_surface_runoff/Ground or water surface (8)
Total_precipitation/Ground or water surface (8)
Water_equivalent_of_accumulated_snow_depth/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\NAM_CONUS_12km_20100520_0000.grib2
Convective_precipitation/Ground or water surface (8)
Probability_of_freezing_precipitation/Ground or water surface (8)
Probability_of_frozen_precipitation/Ground or water surface (8)
Probability_of_p01_inch_precipitation/Ground or water surface (8)
Thunderstorm_probability/Ground or water surface (8)
Total_precipitation/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\NAM_CONUS_20km_selectsurface_20100426_1800.grib2
Baseflow_groundwater_runoff/Ground or water surface (8)
Convective_precipitation/Ground or water surface (8)
Downward_long_wave_rad_flux/Ground or water surface (8)
Downward_short_wave_rad_flux/Ground or water surface (8)
Evaporation/Ground or water surface (8)
Ground_Heat_Flux/Ground or water surface (8)
Large_scale_precipitation/Ground or water surface (8)
Latent_heat_net_flux/Ground or water surface (8)
Potential_Evaporation/Ground or water surface (8)
Probability_of_freezing_precipitation/Ground or water surface (8)
Probability_of_frozen_precipitation/Ground or water surface (8)
Probability_of_p01_inch_precipitation/Ground or water surface (8)
Sensible_heat_net_flux/Ground or water surface (8)
Snow_depth/Ground or water surface (8)
Snow_melt/Ground or water surface (8)
Snow_phase_change_heat_flux/Ground or water surface (8)
Storm_surface_runoff/Ground or water surface (8)
Thunderstorm_probability/Ground or water surface (8)
Total_cloud_cover/Entire atmosphere layer (8)
Total_precipitation/Ground or water surface (8)
Upward_long_wave_rad_flux/Ground or water surface (8)
Upward_long_wave_rad_flux/Nominal top of the atmosphere (8)
Upward_short_wave_rad_flux/Ground or water surface (8)
Upward_short_wave_rad_flux/Nominal top of the atmosphere (8)
Water_equivalent_of_accumulated_snow_depth/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\NAM_CONUS_20km_surface_20100429_0600.grib2
Baseflow_groundwater_runoff/Ground or water surface (8)
Convective_precipitation/Ground or water surface (8)
Deep_convective_heat_rate/Entire atmosphere layer (8)
Downward_short_wave_rad_flux/Ground or water surface (8)
Large_scale_condensate_heat_rate/Entire atmosphere layer (8)
Snow_melt/Ground or water surface (8)
Storm_surface_runoff/Ground or water surface (8)
Total_precipitation/Ground or water surface (8)
Water_equivalent_of_accumulated_snow_depth/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\NAM_CONUS_40km_conduit_20100506_1800.grib2
Baseflow_groundwater_runoff/Ground or water surface (8)
Convective_precipitation/Ground or water surface (8)
Downward_long_wave_rad_flux/Ground or water surface (8)
Downward_short_wave_rad_flux/Ground or water surface (8)
Evaporation/Ground or water surface (8)
Ground_Heat_Flux/Ground or water surface (8)
Large_scale_precipitation/Ground or water surface (8)
Latent_heat_net_flux/Ground or water surface (8)
Potential_Evaporation/Ground or water surface (8)
Probability_of_freezing_precipitation/Ground or water surface (8)
Probability_of_frozen_precipitation/Ground or water surface (8)
Probability_of_p01_inch_precipitation/Ground or water surface (8)
Sensible_heat_net_flux/Ground or water surface (8)
Snow_depth/Ground or water surface (8)
Snow_melt/Ground or water surface (8)
Snow_phase_change_heat_flux/Ground or water surface (8)
Storm_surface_runoff/Ground or water surface (8)
Thunderstorm_probability/Ground or water surface (8)
Total_cloud_cover/Entire atmosphere layer (8)
Total_precipitation/Ground or water surface (8)
Upward_long_wave_rad_flux/Ground or water surface (8)
Upward_long_wave_rad_flux/Nominal top of the atmosphere (8)
Upward_short_wave_rad_flux/Ground or water surface (8)
Upward_short_wave_rad_flux/Nominal top of the atmosphere (8)
Water_equivalent_of_accumulated_snow_depth/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\NAM_Polar_90km_20100525_1200.grib2
Baseflow_groundwater_runoff/Ground or water surface (8)
Convective_cloud_cover/Entire atmosphere layer (8)
Convective_precipitation/Ground or water surface (8)
Downward_long_wave_rad_flux/Ground or water surface (8)
Downward_short_wave_rad_flux/Ground or water surface (8)
Evaporation/Ground or water surface (8)
Ground_Heat_Flux/Ground or water surface (8)
Large_scale_precipitation/Ground or water surface (8)
Latent_heat_net_flux/Ground or water surface (8)
Non-Convective_Cloud_Cover/Entire atmosphere layer (8)
Potential_Evaporation/Ground or water surface (8)
Sensible_heat_net_flux/Ground or water surface (8)
Snow_melt/Ground or water surface (8)
Snow_phase_change_heat_flux/Ground or water surface (8)
Storm_surface_runoff/Ground or water surface (8)
Total_cloud_cover/Entire atmosphere layer (8)
Total_precipitation/Ground or water surface (8)
Upward_long_wave_rad_flux/Ground or water surface (8)
Upward_long_wave_rad_flux/Nominal top of the atmosphere (8)
Upward_short_wave_rad_flux/Ground or water surface (8)
Upward_short_wave_rad_flux/Nominal top of the atmosphere (8)
Water_equivalent_of_accumulated_snow_depth/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\NDFD_CONUS_5km_20100527_1200.grib2
Maximum_temperature/Specified height level above ground (8)
Minimum_temperature/Specified height level above ground (8)
Probability_of_p01_inch_precipitation/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\RUC2_CONUS_20km_hybrid_20100421_2000.grib2
Convective_precipitation/Ground or water surface (8)
Large_scale_precipitation/Ground or water surface (8)
Water_equivalent_of_accumulated_snow_depth/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\RUC2_CONUS_20km_pressure_20100509_1300.grib2
Convective_precipitation/Ground or water surface (8)
Large_scale_precipitation/Ground or water surface (8)
Water_equivalent_of_accumulated_snow_depth/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\RUC2_CONUS_20km_surface_20100516_1600.grib2
Convective_precipitation/Ground or water surface (8)
Large_scale_precipitation/Ground or water surface (8)
Water_equivalent_of_accumulated_snow_depth/Ground or water surface (8)
Q:\cdmUnitTest\tds\new\SREF_Alaska_45km_ensprod_20100525_0300.grib2
Large_scale_snow/Ground or water surface (9)
Total_precipitation/Ground or water surface (9)
Q:\cdmUnitTest\tds\new\SREF_CONUS_40km_ensprod_20100513_1500.grib2
Large_scale_snow/Ground or water surface (12)
Large_scale_snow/Ground or water surface (9)
Total_precipitation/Ground or water surface (9)
Total_precipitation/Ground or water surface (12)
Q:\cdmUnitTest\tds\new\SREF_PacificNE_0p4_ensprod_20100509_2100.grib2
Total_precipitation/Ground or water surface (9)
Total_precipitation/Ground or water surface (12)
=====================
GRIB1 datasets with variables that are affected. The number in () is the
time range indicator code.
/share/testdata/cdmUnitTest/tds/new/GFS_Alaska_191km_20100507_1800.grib1
APCP Total_precipitation (4)
/share/testdata/cdmUnitTest/tds/new/GFS_CONUS_80km_20100513_0600.grib1
APCP Total_precipitation (4)
/share/testdata/cdmUnitTest/tds/new/GFS_CONUS_95km_20100506_0600.grib1
ACPCP Convective_precipitation (4)
APCP Total_precipitation (4)
/share/testdata/cdmUnitTest/tds/new/GFS_Hawaii_160km_20100428_0000.grib1
ACPCP Convective_precipitation (4)
APCP Total_precipitation (4)
/share/testdata/cdmUnitTest/tds/new/GFS_N_Hemisphere_381km_20100516_0600.grib1
ACPCP Convective_precipitation (4)
APCP Total_precipitation (4)
/share/testdata/cdmUnitTest/tds/new/NAM_Alaska_22km_20100504_0000.grib1
ACPCP Convective_precipitation (4)
APCP Total_precipitation (4)
WEASD Accumulated_snow (4)
/share/testdata/cdmUnitTest/tds/new/NAM_Alaska_95km_20100502_0000.grib1
ACPCP Convective_precipitation (4)
APCP Total_precipitation (4)
/share/testdata/cdmUnitTest/tds/new/NAM_CONUS_20km_noaaport_20100602_0000.grib1
ACPCP Convective_precipitation (4)
APCP Total_precipitation (4)
CPOFP Prob_of_frozen_precipitation (4)
CPOZP Prob_of_freezing_precipitation (4)
POP Prob_of_precipitation (4)
SNOD Snow_depth (4)
TSTM Thunderstorm_probability (4)
/share/testdata/cdmUnitTest/tds/new/NAM_CONUS_80km_20100508_1200.grib1
ACPCP Convective_precipitation (4)
APCP Total_precipitation (4)
/share/testdata/cdmUnitTest/tds/new/RUC2_CONUS_40km_20100515_0200.grib1
ACPCP Convective_precipitation (4)
NCPCP Large_scale_precipitation (4)
WEASD Accumulated_snow (4)
/share/testdata/cdmUnitTest/tds/new/RUC_CONUS_80km_20100430_0000.grib1
ACPCP Convective_precipitation (4)
APCP Total_precipitation (4)
NCPCP Large_scale_precipitation (4)
