Lifted Index (LI) Lifted Index (LI) Thunderstorm Indication < -5
Very Unstable, Heavy/strong thunderstorm potential
-3 to -5
Unstable, Thunderstorms probable
0 to -2
Marginally Unstable, Thunderstorms possible
It is a stability index used to determine thunderstorm potential.
(abbrev. LI)- A common measure of atmospheric instability.
Lifted Index (LI): It is a stability index used to determine thunderstorm potential. The LI is calculated by taking a representative low level air parcel and lifting it adiabatically to 500 mb.
Lifted Index (LI) - A common measure of atmospheric instability. Negative values indicate instability - the more negative, the more unstable the air is, and the stronger the updrafts are likely to be with any developing thunderstorms.
LIFTED INDEX- The environmental temperature at 500 millibars minus the 500 millibar parcel temperature on a Skew-T diagram. Negative LI values are unstable.
LLJ- Low Level Jet. Strong Planetary Boundary Layer winds which advect warmer temperatures and moisture into the forecast area.
The ~ is a measure of atmosphere's stability (or instability) and Meteorologists use it to determine the thunderstorm potential.
~ - A measurement of the instability of the atmosphere based on the temperature difference between a parcel of air from the surface and the ambient air at 500 Mb pressure altitude (18,500 feet). If this number is negative, there is enough instability for thunderstorms. Also called LI.
Related Term : Lifted Index
2. National Oceanographic and Atmospheric Administration (NOAA ) ...
LFTLiftLGTLightLGWVLong WaveLILifted Index. A common measure of atmospheric instability.
MLLIMean Layer Lifted Index - Lifted Index (LI) calculated using a parcel consisting of Mean Layer values of temperature and moisture from the lowest 100 mb above ground level. See Lifted Index (LI).MLLW(Mean Lower Low Water) - A tidal datum.
In cases of elevated convection, stability indices based on near-surface measurements (such as the lifted index) typically will underestimate the amount of instability present. Severe weather is possible from elevated convection, but is less likely than it is with surface-based convection.
LI - Abbreviation for lifted index.
lid - (Also known as cap, capping inversion, capping layer.) A thin layer with enhanced static stability separating a layer below possessing large convective available potential energy from a layer above with lower static stability.
Degree of conformity of a measure to a standard or true value; in other words, how close a predicted or measured value is to the true value.
NOAA National Weather Service - Cite This Source - This Definition
Browse Related Terms: bias, Delta T, Li, Lifted Index, MLLI, MULI, Sweat, ...
for air parcels to accelerate when they are displaced from their original position; especially, the tendency to accelerate upward after being lifted. Instability is a prerequisite for severe weather - the greater the instability, the greater the potential for severe thunderstorms. See lifted index ...
See also: What is the meaning of Weather, Air, Thunder, Thunderstorm, Temperature?