Precipitation and the Sounding Diagram, Page 8 of 10

Before we finish, here's a quick application of this newfound skill. On a sunny afternoon, particularly in the summer, you often see cumulus clouds forming. These clouds are at the top of the boundary layer, and are produced by air which has been warmed (and sometimes moistened) at the ground and has risen until its water vapor has begun to condense.

You can determine the height of these cloud bases if you know the pressure, temperature, and dew point of the air at the ground. Let's take a concrete example: typical summertime conditions in College Station feature a temperature of 31 C and a dew point of 25 C. A typical sea level pressure is 1016 mb; correct for the elevation of College Station (115 m) and you get 1005 mb, which is close enough to 1000 mb that I'm not going to worry about the difference.

Now find the spot on the diagram below which corresponds to the surface temperature and pressure, and CLICK ON IT! That's right, click. If you select the right spot, you'll automatically move on to the next page.

Questions or Comments

Technical: E-mail John Fulton < jdfult@nimbus.met.tamu.edu >
Scientific: E-mail Dr. John Nielsen-Gammon. < nielsen@ariel.met.tamu.edu >