Which prefix is commonly associated with middle clouds?

The prefix that is commonly associated with middle clouds is "Alto." This term signifies that these clouds typically form at altitudes ranging from approximately 2,000 to 7,000 meters (around 6,500 to 23,000 feet) in the atmosphere. Middle clouds often consist of altostratus and altocumulus types, which are characterized by their mid-level formation and distinct appearances.

The prefix "Strato" relates to low clouds, indicating their formation at lower altitudes. "Cumulus" describes clouds that are typically puffy and associated with vertical development, primarily found at lower altitudes. "Nimbo" suggests rain, either as a standalone prefix indicating rain-producing clouds or combined with "stratus" or "cumulus" in terms such as nimbo-stratus or nimbo-cumulus. Thus, "Alto" is the appropriate prefix to indicate the classification of middle clouds.