Airport Identifier, Timestamp & Wind Groups
The report begins with the four-letter ICAO station identifier (e.g., KJFK), followed by the date and time of observation in UTC (e.g., 281400Z). Modifiers like AUTO indicate automated sensor generation, while COR signifies a corrected bulletin.
The wind group provides true direction in three digits and speed in knots (e.g., 14012G22KT for 140° at 12 knots gusting to 22 knots). Variable winds are denoted by VRB or directional range brackets such as 090V160.
Visibility, Runway Visual Range (RVR) & Weather Phenomena
Horizontal visibility is reported in statute miles (US) or meters (ICAO). 9999 represents 10 km or greater. Runway Visual Range (RVR) follows the format R10/1200N for runway 10 with 1,200 meters visual range.
Weather phenomena combine intensity qualifiers (+ heavy, - light), descriptors (TS thunderstorm, SH shower, FZ freezing), and precipitation types (RA rain, DZ drizzle, SN snow, FG fog, BR mist, HZ haze).
Cloud Cover, Ceilings & Altimeter Settings
Cloud amount is categorized in oktas: FEW (1-2), SCT (3-4), BKN (5-7), and OVC (8), followed by base height in hundreds of feet AGL (e.g., BKN025 = ceiling at 2,500 ft). Convective clouds carry CB (Cumulonimbus) or TCU (Towering Cumulus) suffixes.
Temperature and dew point appear as 24/18 (24°C temperature, 18°C dew point; sub-zero values prefix M). Altimeter setting is reported as A2992 (inches of mercury) or Q1016 (hectopascals).