It is the summer season in the southeastern United States and convective activity is expected
during the afternoon. Use the 1200 UTC sounding above to forecast the turbulence intensity
associated with convection that develops later in the day. Use the "Eastern Airlines Method"
as guidance.
Answer: Delta-T is approximately 7°C (see graphic).
From the CCL, proceed upward along a moist adiabat to 400 hPa, where parcel
temperature (T') = -15°C and the sounding temperature (T
400) is -22°C.
Therefore:
Delta-T = T' - T400 = (-15) - (-22) = 7°C.
What turbulence intensity would you expect?
Please select an answer from the list below.
Turbulence intensity =
Answer: Severe turbulence.
From the table on the previous page, a delta-T of 7°C falls in the 7-9°C range,
which indicates the potential for severe turbulence.
Based on this sounding, aviation interests would be notified a potentially dangerous situation
could occur during afternoon convection.