At Australian Capital City sites, all soundings between 2008-2015 were extracted from the BoM. Thunderstorm soundings were identified using GPATS lightning strike data. A sounding was flagged as a thunderstorm sounding if, (a) 1 or more strikes occurred within a 0.5 degree lat/lon box centered about the sounding site, and (b) within +-1hour from the sounding time. A total of 316 thunderstorm soundings were identified using this method.
For each thunderstorm sounding the following was calculated:
Theta Surface (K)
Theta Max upper (K)
Lev Theta Max upper (hPa)
Theta E Surface (K)
Theta E Max upper (K)
Lev Theta E Max upper (hPa)
CAPE Surface (J)
CIN Surface (J)
Lev Surface (hPa)
T Surface (C)
TD Surface (C)
MUCAPE (J)
MUCIN (J)
Lev MUCAPE (hPa)
T MUCAPE (C)
TD MUCAPE (C)
Typical MUCAPE calculations use the parcel which has the highest equivalent potential temperature value in the lowest 300hPa of the sounding, i.e. from 1000-700hPa (REF). However some Elevated Thunderstorm case study soundings (REF) have identified the most unstable parcel occuring above 700hPa.
Using thetae through large depth of atmosphere can be problematic. Thetae asymptotes to theta when the atmophere is very dry. Since theta increases with height, if a dry layer exists the maximum thetae value level within the upper dry layer. Using such a dry parcel would underestimate MUCAPE. Theta and Thtae calculations are deliberately restricted to the lowest 300hPa, to ensure no dry layers are encountered.
MUCAPE therefore was calculated by lifting parcels at every sounding level between 1000-500hPa.