III. Sky Condition, Visibility and Present Weather

Reporting Present and Significant Weather

Reporting Present and Significant Weather

You should report all present weather occurring at the ship at the time of the observation using the symbols and intensity signs given in the summary table here. Obscurations should be entered for any obstructions restricting the prevailing visibility to 6 nm or less. Enter phenomena not occurring directly at the ship in the remarks section.

Summary Table of Obscuration Identifiers
Intensity or Proximity Intensity/Proximity Symbol Descriptor Precipitation Obscuration Other
Light - MI    Shallow DZ  Drizzle BR  Mist PU Well-developed Dust/Sand Whirls
Moderate (no symbol) PR  Partial RA  Rain FG  Fog SQ  Squalls
Heavy + BC  Patches SN  Snow FU  Smoke +FC  Tornado or Waterspout
Vicinity VC DR  Low Drifting SG Snow Grains VA   Volcanic Ash FC  Funnel Cloud
Distant DSNT BL   Blowing IC  Ice Crystals DU  Widespread Dust SS  Sandstorm

SM  Showers PL Ice Pellets SA  Sand DS  Duststorm

TS  Thunderstorm GR  Hail HZ  Haze


FZ    Freezing GS  Small Hail or Snow Pellets PY  Spray

Clouds over the sea

The Remarks and Supplemental Coded Data section should include information about:

  • Breaks in an obscured sky condition.
  • Conditions significant to aircraft or ship operations.
  • The direction and location of visible phenomena in a clockwise order using the eights of the compass.
  • Movement of clouds or other phenomena with respect to the location and direction toward which the phenomena are moving.
  • Distances of the phenomena based on radar, pirep, or other reliable estimation. Phenomena occurring between 5 and 10 nm are reported as Vicinity (VC). Phenomena occurring beyond 10 nm are considered Distant (DSNT).
  • Remarks pertaining to tornadic or thunderstorm activity may be combined with those for cumulonimbus or cumulonimbus mammatus when the direction of movement is the same.
  • Three- and six-hourly synoptic cloud types should be entered. A "0" should be encoded if no cloud is present at a low, middle, or high classification.
  • The 5appp pressure tendency should be included in the three- and six-hourly observations only when the ship is at anchor or moored for more than 3 hours.
  • The sea-level pressure SLPppp should be included in hourly observations and encoded in tens, units, and tenths of sea level pressure.