What does the abbreviation "FU" refer to in aviation weather?

The abbreviation "FU" in aviation weather refers specifically to smoke. This term is often used in aviation reports and forecasts to indicate areas where smoke is present, which can significantly impact visibility and overall flight safety. Smoke can originate from various sources, including wildfires, industrial activities, or volcanic eruptions. Since it can create hazardous conditions for pilots, it's crucial for aviators to be aware of smoke reports in the areas they are flying.

Funnel cloud, fog, and freezing rain all have their own distinct abbreviations in aviation meteorology. For example, fog is typically denoted as "FG," while freezing rain would be referred to as "ZR" or "FZRA." Understanding these terms is essential for pilots and aviation meteorologists to communicate effectively about weather conditions that may affect aviation operations.