NCEP SHORT-RANGE ENSEMBLE FORECAST (SREF)

NCEP's Short-Range Ensemble Forecast (SREF) system is a dual-core multi-physics regional ensemble over North America. It consists of 26 members, 13 using the Advanced Research WRF (WRF-ARW) model and 13 members using the NEMS Non-Hydrostatic Multiscale Model on B-grid (NEMS-NMMB). SREF is run to 87-h at 16 km horizontal resolution with 40 vertical layers at 0300, 0900, 1500, and 2100 UTC. To create ensemble diversity a mix of different physics parameterizations, lateral boundary conditions (LBC) from the Global Ensemble Forecast System (GEFS), and initial conditions are used. Table 1 shows the physics configuration used for the 13 NEMS-NMMB members, and Table 2 shows the configurations used for the WRF-ARW members.

The October 2015 SREF implementation was its last upgrade, as future regional ensemble development at NCEP will focus on building a high-resolution convective-allowing ensemble including the FV3 dynamic core. 

Table 1 : Physics, initial conditions, and lateral boundary conditions used in the 13 NEMS-NMMB SREF members; click here for definition of acronyms.

SREF-Related Web Pages

• Official NCEP MAG SREF Page

• SPC SREF Web Page
• SPC SREF Plumes Page 

Information about NCEP SREF

• Oct 21, 2015 SREF Upgrade
• Past Upgrades
• References
• SREF Data on NCEP NOMADS
• SREF Verification

Other Time-lagged Ensemble Products

• North America Rapid Refresh Ensemble -- Time Lagged (NARRE-TL)
• High-Resolution Ensemble Forecast (HREF)
• SPC HREF site

 

PLEASE READ THE DISCLAIMER

For more info about the NCEP SREF, please contact: Jun Du For more info about the NARRE-TL, please contact: Binbin Zhou For more info on the HREF, please contact Matthew Pyle