As is often the case this time of year, California is hot, especially in theinterior. This hot weather is not helping matters out for firefighters inSouthern California, as little or no relief is in sight.What is causing all this hot weather? Well, a large high pressure system hasset up north of the state, and this causes an offshore flow from the east. Notonly is this air dry and warm to begin with, it is now forced to drop inelevation as it travels from the Sierra Nevada and the elevated plateau that isthe Intermountain West to the Pacific Ocean. This drop in elevation increasesthe air's temperature, thus decreasing its relative humidity, a bad combinationfor firefighters.

Commentary by AccuWeather.com Meteorologist Mark Paquette.