Thickness


Critical Thickness

Have you ever wondered what tool a meteorologist uses to predict what type (liquid vs. frozen) of precipitation will fall? Well, look no farther than the upper right hand panel of the computer model maps for the answer to this question. You may notice when you look at this panel a bold dashed line labeled 540 (blinking red). Please be advised here that not all computer models bold this dashed line. Meteorologists call this line the critical thickness. This line is the 1000-500 mb thickness that represents a 50% probability that frozen and/or liquid precipitation will fall along it. Please keep in mind that this bolded critical thickness does not apply to all regions of the country. In State College the critical thickness is 542(dam) but amongst friends what is a couple decameters (dam)? You can use the 540(dam). In Denver, for example, meteorologists use the critical thickness of 552.