On August 21, 2012, NCEP will be upgrading the Short-Range Ensemble Forecast System (SREF). SREF output is delivered to Unidata community members via the CONDUIT data stream.
The full details of the SREF upgrade are available in NWS TIN 12-30.
Rebecca Cosgrove of NWS/NCEP Central Operations writes:
Briefly, the models that make up the SREF will be changing. Currently the SREF is comprised of individual Eta, RSM, WRF NMM and WRF ARW members. With the upgrade, the Eta and RSM members will be removed and NMMB members will be added. In addition, the native horizontal resolution of all the members will be increased to 16km.
The impact to the CONDUIT data stream will be that on the 21st, the individual NMMB members will be added to CONDUIT, and the Eta and RSM member output will be removed. In addition, bias-corrected ensemble precipitation fields will be added to CONDUIT. At this time we do not plan to add the new 16km output to CONDUIT, but if there is interest in these products, please let us know.
Please also note that, as described in the TIN, the model process id number in the GRIB encoding of the WRF NMM and WRF ARW individual member products will be changing. Currently all individual SREF members are encoded in GRIB with process number 84. With this upgrade, the process numbers will be 111 for the NMMB, 112 for the WRF NMM, and 116 for the WRF ARW. The process number for the SREF ensemble products will continue to be 113 as it is now.
I encourage you to read through the TIN for all the changes coming with this upgrade. Also, please note that due to the increased compute resources required to run this upgraded SREF, in the event that the NCEP production suite is delayed, the SREF may not be run for a given cycle to preserve the timeliness of other NCEP models. This is a temporary situation until we move to our new supercomputers in mid-2013. More details on this potential for cancellation of the SREF and the downstream impacts are described in TIN 12-33.