On Sat, 2 May 2009 02:31:18 -0700 (PDT), "
wrote:

[snip]
And clearly the precipitation in the tropics peaks with the heat and
at the poles with the cold:

http://www.atmos.washington.edu/~ign..._PHASE.obs.jpg


Only in that the heat and low density due to moisture driving
convection up to where cold air causes the precipitation.

Precipitation may be discussed as droplets finding a particle
to cling to, things can get really extreme when there is a strong
interface of temperature differences.

The weather phenomenon called "derecho" (straight line
winds moving rapidly), I was in one in 1969, and watched the
radar of another a couple of years ago, the only two I am
aware of in 80 years.
The one in 1969 had winds where I was near Lake Erie
of well over 100 miles per hour, and lasted at least 5 minutes,
taking down more than half of the mature trees in Lakewood,
Ohio where trees were everywhere.

It may not have been apparent, but precipitation
must have been driving that.