This is a list of acronyms and abbreviations SPC frequently uses in our
products.
NOTE:
Weather station IDs referenced in SPC outlooks and other NWS products may
be found by state in this
List of Surface Stations by Greg Thompson of UCAR.
CAPE calculated using a parcel from a pressure level that results in the Most Unstable CAPE possible
MLCAPE
CAPE calculated using a parcel consisting of Mean Layer values of temperature and moisture from the lowest 100 mb above ground level
*ETA* SBCAPE
SBCAPE values obtained using ETA model soundings
*ETA* MUCAPE
MUCAPE values obtained using ETA model soundings
*ETA* MLCAPE
MLCAPE values obtained using ETA model soundings
substitute model preference.
For more information on the origin of these instability acronyms, click here.
LI calculated using a parcel from the pressure level that results in the Most Unstable value (lowest value) of LI possible
MLLI
LI calculated using a parcel consisting of Mean Layer values of temperature and moisture from the lowest 100 mb above ground level
*ETA* SBLI
SBLI values obtained from ETA model soundings
*ETA* MULI
MULI values obtained from the ETA model soundings
*ETA* MLLI
MLLI values obtained from ETA model soundings
*ETA* LI
LI gridpoint values calculated by ETA model postprocessing
*NGM* LI
LI gridpoint values calculated by NGM model postprocessing
*RUC* LI
LI gridpoint values calculated in-house using values from the RUC model **substitute model preference.
For more information on the origin of these instability acronyms, click here.
weather.gov 
