Vaisala PWD22 - Index

Appendix C ________________________________________________ NWS and WMO Code Tables
VAISALA ______________________________________________________________________ 113
APPENDIX C
NWS AND WMO CODE TABLES
Table 25 Internal Weather Types and Supported NWS Codes
Internal Weather Types
NWS Codes
NO PRECIPITATION
C
PRECIPITATION
P
DRIZZLE
L
RAIN
R
SNOW
S
SLEET
IP
FREEZING DRIZZLE
ZL
FREEZING RAIN
ZR
NWS codes are used with intensity indicator '+' (plus) for heavy
intensity, '-' (minus) for light, and none (space) for moderate. For
example, 'R+' means heavy rain.
Table 26 WMO SYNOP Codes (Table 4680, W
a
W
a
) Used by
PWD22/52
SYNOP Codes
Weather Types
00
Clear
04
Haze or smoke, or dust in suspension in the air, visibility equal to, or greater
than, 1 km
05
Haze or smoke, or dust in suspension in the air, visibility less than 1 km
10
Mist
Code figures 20 to 25 are used, if precipitation or fog was observed during the preceding hour but not at
the time of observation
20
Fog
21
PRECIPITATION
22
Drizzle (not freezing) or snow grains
23
Rain (not freezing)
24
Snow
25
Freezing rain or freezing drizzle
The following code figures are used if precipitation or fog is observed at the time of observation
30
FOG
31
Fog or ice fog, in patches
32
Fog or ice fog, has become thinner during the past hour
33
Fog or ice fog, no appreciable change during the past hour
34
Fog or ice fog, has begun or become thicker during the past hour
40
PRECIPITATION
41
Precipitation, slight or moderate
42
Precipitation, heavy
50
DRIZZLE