Storm top dynamics
Storm top cooling rates
Cloud top cooling rates can be converted directly to vertical velocity if you know the lapse rate at the top of the tower. We could use the moist adiabatic lapse rate appropriate for the particular growing convective cloud. Use the following relationship,
At GOES resolutions, the vertical velocity of a growing tower will be
underestimated. Consider a cloud top cooling rate of 2° K min-1 and a lapse rate of 8° K km-1.
Substituting into ,
w = 4 m/s.
This is a low estimate, especially for thunderstorms because:
- The 2 X 4 km resolution is larger than a typical growing tower
- Most towers grow in spurts, therefore, the temporal resolution will not capture the largest cooling rates.
- The largest vertical velocities maybe in the cloud interior.
Other aspects of cooling rate.
- Growing tower below equilibrium level.
- Growing overshoot above equilibrium level