2. Parameters

Temperature/Levels » Equivalent Potential Temperature (Theta-e) Skew-T Procedure

Skew-T procedure to determine equivalent potential temperature

Skew-T Procedure:

  1. From the dewpoint at the given pressure, draw a line upward along a saturation mixing-ratio line. Also, from the T curve at the given pressure, draw a line upward along a dry adiabat until it intersects the line drawn from the dewpoint at the LCL.
  2. From this intersection, follow a saturation adiabat upward to a pressure where the saturation adiabat parallels the dry adiabat. This is the pressure level where all the moisture has been condensed out of the sample.
  3. From this pressure, follow the dry adiabat down to the 1000 hPa isobar. The temperature where the dry adiabat crosses the 1000 hPa isobar is the equivalent potential temperature (theta-e).

In this example, air at 850 hPa with T = 10°C and Td = -8°C has an equivalent potential temperature of about 32°C.