(e) Obstructions to visibility. There are eight types of obscuration phenomena in the METAR code (obscurations are any phenomena in the atmosphere, other than precipitation, that reduce horizontal visibility): FG fog (vsby less than 5/8 mile) HZ haze FU smoke PY spray BR mist (vsby 5/8 - 6 miles) SA sand DU dust VA volcanic ash NOTE- Fog (FG) is observed or forecast only when the visibility is less than five-eighths of mile, otherwise mist (BR) is observed or forecast. (f) Other. There are five categories of other weather phenomena which are reported when they occur: SQ . squall SS . sandstorm DS . duststorm PO dust/sand whirls FC . funnel cloud +FC . tornado/waterspout Examples: TSRA . thunderstorm with moderate rain +SN heavy snow -RA FG . light rain and fog BRHZ mist and haze (visibility 5/8 mile or greater) FZDZ . freezing drizzle VCSH rain shower in the vicinity +SHRASNPL heavy rain showers, snow, ice pellets (intensity indicator refers to the predominant rain) 9. Sky Condition. The sky condition as reported in METAR represents a significant change from the way sky condition is currently reported. In METAR, sky condition is reported in the format: Amount/Height/(Type) or Indefinite Ceiling/Height (a) Amount. The amount of sky cover is reported in eighths of sky cover, using the contractions: SKC . clear (no clouds) FEW >0 to 2/8 SCT . scattered (3/8s to 4/8s of clouds) BKN . broken (5/8s to 7/8s of clouds) OVC . overcast (8/8s clouds) CB Cumulonimbus when present TCU . Towering cumulus when present NOTE- 1. "SKC" will be reported at manual stations. "CLR" will be used at automated stations when no clouds below 12,000 feet are reported. 2. A ceiling layer is not designated in the METAR code. For aviation purposes, the ceiling is the lowest broken or overcast layer, or vertical visibility into an obscuration. Also there is no provision for reporting thin layers in the METAR code. When clouds are thin, that layer must be reported as if it were opaque. (b) Height. Cloud bases are reported with three digits in hundreds of feet above ground level (AGL). (Clouds above 12,000 feet cannot be reported by an automated station). 7-1-70 Meteorology