Whats the name for rain that falls from the cloud base, but disappears before reaching the ground?
— Patricia Delaney A: When a shaft of precipitation, liquid or frozen, drops from a cloud but evaporates before it reaches the ground, it is called virga. These streaks of precipitation often look like little legs protruding from the bases of clouds. Just as the temperature of air varies with altitude, the relative humidity can vary at different levels in the atmosphere. In the case of virga, the atmosphere is saturated at cloud level, but precipitation evaporates completely as it falls into much drier air. This old-school USA TODAY weather graphic explains how virga forms.— Danny Chaitin ****************************************************************************************** Q: I’ve noticed contrails forming in a criss-cross pattern and spreading across the sky until it’s covered in haze — What is happening?— Darren Wagner A: Contrails (short for “condensation trails”) are clouds that form when the hot air exhausted from jet engines mixes with cold air high in the atmosphere (many c
