Grey or
White-lines: Lifted
Index solid grey lines > 0 (poor LI values), dashed
white lines<=0degC (moderate or 'good' LI values)
CAPE (Convective Available Potential Energy) See scale at
right of diagram: blue/green - low values of CAPE
, orange/red - high values of CAPE
Critical values CAPE:
<300
: little or no convective potential.
300 to1000 : weak convective potential.
1000 to 2500: moderate convective potential.
> 2500 :
strong convective potential.
Tests on the field shows there isno
good correlationbetween
CAPE values and severe weather events. (Weak CAPE and strong wind shear
may also produce severe thunderstorms).
Critical values LI (not to be used in winter):
>0 : unlike
potential for thunderstorms.
0 to -2 : weak potential, but with trigger (front, trough,
orography).
-3 to -5 : moderate potential.
< -5 : strong potential.
Tests on the field shows there isgood
correlationbetween LI
values < -5 and severe weather events.