What is the approximate altitude in feet ASL for 500 hPa?

To determine the altitude corresponding to a pressure level of 500 hPa, it's essential to understand the relationship between atmospheric pressure and altitude. The standard atmosphere model indicates that as altitude increases, atmospheric pressure decreases. At sea level, the pressure is approximately 1013 hPa.

The 500 hPa pressure level is commonly used in meteorology to represent an altitude where the air pressure is about half of what it is at sea level. Typically, this level is found around 18,000 feet above sea level (ASL). This altitude can vary depending on atmospheric conditions, but 18,000 feet is a widely accepted approximation in aviation and meteorological contexts.

Since the altitude at 500 hPa is around 18,000 feet, this aligns with the selected answer, confirming its accuracy based on standard atmospheric conditions and the concepts of altitude pressure relationships.