What does the TAF indicate when it states "4SM HZ TEMPO 0006 2SM BR HZ"?

The statement "4SM HZ TEMPO 0006 2SM BR HZ" from the TAF (Terminal Aerodrome Forecast) indicates specific conditions expected at the airport. This notation implies that there will generally be visibility of four statute miles, but there will also be temporary periods when visibility drops to two statute miles due to mist (BR) and haze (HZ).

The use of "TEMPO" suggests that the lower visibility conditions are not constant but will occur intermittently, hence the significance of the word "occasional." The inclusion of "HZ" confirms the presence of haze, contributing to the reduced visibility at times.

This interpretation highlights the fluctuating weather conditions forecasted, which can impact flight operations, making it crucial for pilots to be aware of these variations. Hence, while a visibility of four statute miles is expected overall, the forecast clearly communicates that temporary reductions to two statute miles should also be anticipated.