What does the term "BR" refer to in a METAR report?

In a METAR report, the term "BR" specifically refers to "Mist." This is a weather phenomenon characterized by reduced visibility, typically caused by small water droplets suspended in the air. Mist presents visibility less than 7 statute miles but greater than 1/4 mile, which can affect flight operations and ground activities, making it important information for pilots and meteorologists.

Understanding "BR" as mist helps in interpreting weather conditions accurately. The other options do not apply: "broad range visibility" is not a recognized aviation term in METAR reporting, "broken clouds" is denoted by "BKN" in METAR, and "barometric pressure readings" are referenced differently, usually in terms of inches of mercury or hectopascals, so they aren't encapsulated by "BR." Recognizing "BR" as mist is crucial for situational awareness, especially in aviation contexts where visibility is a key factor in safety.