On Wed, 15 Aug 2007 07:37:59 -0700, Jay Honeck
wrote in .com:

late-afternoon pop-ups are hard to predict

Here's some information:

http://www.drjack.info/INFO/holti.htm
AUTOMATED HOLLISTER THERMAL INDEX PREDICTION (TIP) PROGRAM

http://aviationweather.gov/general/p...ocs/dec-03.pdf
http://www.weather.gov/forecasts/graphical/sectors/

http://www.weather.gov/forecasts/gra....php?element=T