What is the correct report for visibility reduced to 1/4 mile due to smoke?

In aviation meteorology, visibility reported as reduced due to smoke is coded with specific meteorological abbreviations. When visibility drops to 1/4 mile because of smoke, the correct report is represented by the abbreviation for mist, which is "BR." This indicates light precipitation, such as mist or haze, which can include smoke.

Using "BR" efficiently communicates that visibility is affected by low atmospheric conditions, even if the specific cause is smoke or haze. The other abbreviations would not accurately reflect the situation of reduced visibility due to smoke. For example, "FU" specifically refers to smoke, but it is used to describe smoke that is present rather than indicating reduced visibility. The abbreviation "SMK" could suggest smoke as well but is not a standard meteorological term used in visibility reporting. "VSBY" is not a recognized aviation code for reporting visibility issues pertaining to specific causes.

Therefore, when visibility is reduced to 1/4 mile due to smoke conditions, utilizing "BR" is the proper and standard way to report this phenomenon in meteorological observations.