This sounding comes from the July 14, 2002 severe thunderstorm outbreak
in southeast Arizona.
Using the mean dewpoint and temperature in the lowest 100 hPa, determine the lifted index (LI).
Enter your answer in the text box below, then click Done.
The correct answer is -4.
Find the mean dewpoint and temperature in the lowest 100 hPa. From the mean dewpoint and temperature at the layer midpoint (about 875 hPa), find the
LCLLCL.
From the LCL, follow a
saturation adiabatsaturation adiabat up to 500 hPa.
The temperature where the saturation adiabat crosses the 500 hPa isobar = T′ = -4°C.
The temperature of the environment at 500 hPa = T500 = -8°C.
LI = T500 - T' = -8 -(-4) = -4