Surface Observation Summary Info
These summaries are tabular lists of the decoded surface observations for
the 24-hour UTC day selected.
The column labels are as follows:
ID TIME T TD RH DIR SPD GST ALT SLP VIS CIL COV WX MAX MIN PR6 PR24 SC
where
ID is the ICAO station identifier column
TIME is the UTC time of the observation
T is the temperature in degrees Celsius
TD is the dewpoint temperature in degrees Celsius
RH is the relative humidity in %
DIR is the wind direction in degrees (referenced from true north)
90 would be a wind blowing from the east
180 would be a wind blowing from the south
270 would be a wind blowing from the west
360 would be a wind blowing from the north
and so on ...
SPD is the wind speed in knots
GST is the gust speed (if reported) in knots
ALT is the abbreviated altimeter setting in inches of Hg
if the first digit listed is 8 or 9, a leading 2 is missing
if the first digit listed is 0 or 2, a leading 3 is missing
Examples: 989 represents 29.89 in. Hg
032 represents 30.32 in. Hg
SLP is the abbreviated sea-level pressure in millibars (mb)
if the first digit is 5 or greater, a leading 9 is missing
if the first digit is less than 5, a leading 10 is missing
Examples: 862 represents 986.2 mb
125 represents 1012.5 mb
VIS is the visibility in statute miles
CIL is the height of the lowest cloud base reported in hundreds of feet
Examples: 8 represents 800 feet
35 represents 3,500 feet
210 represents 21,000 feet
COV is the cloud coverage
X = obscured sky because of fog
CLR or SKC = sky clear of clouds
FEW = few clouds, but less than 2/8 cloud cover
SCT = scattered cloud cover, 2/8 to 4/8 cloud cover
BKN = broken cloud cover, 5/8 to 7/8 cloud cover
OVC = overcast, 8/8 cloud cover
WX is the current weather
Some of the most commonly reported weather conditions are:
HZ = haze
FG = fog
DZ = drizzle
RA = rain
SN = snow
TS = thunderstorm
IP = ice pellets
BR = mist
VC = in the vicinity (accompanied by another symbol)
If any of the above is followed by a "-", it means light intensity
If any of the above is followed by a "+", it means heavy intensity
If neither a "-" or "+", it means moderate intensity
MAX is the maximum temperature (if reported)
Maximum temperatures for the previous 24-hours are usually reported at 0000 UTC
Other maximum temperatures would be over shorter intervals
MIN is the minimum temperature (if reported)
Minimum temperatures for the previous 24-hours are usually reported at 1200 UTC
Other minimum temperatures would be over shorter intervals
PR6 is the precipitation or liquid equivalent amount in inchesover the previous 6-hours
PR24 is the precipitation or liquid equivalent amount in inchesover the previous 24-hours
SC is the snow cover on the ground in inches (if reported) and usually reported at 1200 UTC