METEOAM (cnmc)
Mean zero-crossing wave period issue at step 0
1. Brief description:
Due to the bug in the computation of the second moment and the zero moment of the frequency spectrum (inconsistent diagnostic methods, truncation errors due to limited GRIB precision for the initial conditions) the values of the mean zero-crossing wave period at step 0 are wrong . Affected data:
- 0Z: 2018-11-01...2018-11-05
- 12Z: 2018-10-31...2018-11-04
2. Recommendation:
Do not use the affected data.
SHNSM (sabm)
Wrong peak wave period data
1. Brief description:
Due to the bug in in the determination of the peak wave period values all available data can be affected.
2. Recommendation:
Do not use that parameter until the bug fix is implemented by the provider.
DWD (edzw)
U/V component problem Fixed on 27 June by re-processing and re-archiving all data Feb-Apr 2019
Description:
Problems were identified in DWD operational runs where a recalculation of February to April period has been needed.
GRIB files advanced packing
Different GRIB2 packing than simple (cwao, rjtd, rksl data only)
1. Brief description:
It has been discovered that input data from three providers are using advanced (complex) GRIB packing. It might be useful to have smaller files generally but unfortunately it can create issues in some GRIB tools or for users as e.g. more CPU is needed to process data. For archiving purposes the hardware (tape) packing is used which is a better solution for number of reasons.
2. Recommendation:
Be aware that the centres below (have) used advanced packing. It does not affect data values at all but users can experience slower data processing in some scenarios.
- JMA (rjtd) => changed to simple packing since 0Z 20190403
- ECCC (cwao) => changed to simple packing since 12Z 20190703
- KMA (rksl) => changed to simple packing since 12Z 20190709