METEOROLOGY FLIGHT PLANNING
VARIABLE WINDS: If "VRB" is present in place of the wind direction, the direction cannot be
determined (used with wind speeds of 6 knots or less). If the wind direction is variable with
speeds greater than six knots, a special group will immediately follow the wind group using the
letter "V" between two directions (listed clockwise).
22015KT 180V250 -- Winds from 220º at 15 knots with direction varying from 180 to 250
CALM WINDS: Calm winds are reported as 00000KT.
Peak winds and wind shifts will be reported in the RMK
section of the METAR/SPECI. (See remarks section later in this
2. A sudden increase in wind speed of at least 16 knots and
sustained at 22 knots or more for at least one minute requires that
Squalls (SQ) be reported in the present weather section of the
Group 5: Visibility
METAR uses the prevailing visibility, reported in statute miles (SM) in the United States and in
meters at overseas stations (Figure 1-7). Any of the values in Figure 1-8 may be used.
Automated stations may use "M" to indicate less than one-quarter statute mile when reporting
visibility (think of "Minus"). If visibility is less than seven statute miles, then the
weather/obstruction to vision will also be reported (using the abbreviations discussed later in the
Present Weather section and shown in Figure 1-11).
METAR KNPA 082255Z 27004KT 7/8SM R04/4500FT DZ FG SCT000 BKN011 OVC380
19/18 A2997 RMK VIS1/2V1 CIG009V013 FG SCT000 BKN TOPS 027 SLP149
Figure 1-7 Visibility in METAR
1 1/8 SM -- Visibility one and one-eighth statute miles.
5SM -- Visibility five statute miles.
M1/4 -- Visibility from an automated station less than one-quarter statute mile.
AVIATION ROUTINE WEATHER REPORTS AND TERMINAL AERODROME