The SPC Short-Range Ensemble Forecast (SREF) system is based on 
postprocessing the 15 member NCEP SREF plus the 3-hour time lagged, 
operational (12 km grid spacing) NCEP Eta for a total of 16 members.  

SPC SREF output available through this WEB interface is organized 
similarly to its presentation in the SPC operational display system.  
Start by choosing a general category from the Main Menu (below) as 
well as a forecast hour.  Then, select a specific grid diagnostic 
from the submenu to view in the frame to the right.

All SREF information presented herein is for guidance purposes 
only and should not be confused with official SPC operational 
forecasts.  Links to official SPC operational products are found 
at the bottom of every menu.

Many of the SREF products were developed for testing the utility 
of SREF analysis in the prediction of SPC mission critical items, 
including: thunderstorms and severe thunderstorms, large scale 
critical fire weather conditions, and mesoscale areas of hazardous 
winter weather. In order to accomplish this goal and test new and 
unqiue methods of SREF application in an operational environment, 
many fields not produced in the NCEP postprocessor were calculated 
locally for SPC purposes.