CLASS 20 WMO CODE/FLAG TABLES ASSOCIATED WITH BUFR TABLE B

 

(Version 16.0.0 – 05/04/2011)

 

Notes:   In developing code tables associated with BUFR/CREX Table B to specify units of elements, the following principles should be applied:

 

(a)   Code tables specifying the units for an element which is defined, in the Manual on Codes, by a single symbolic letter shall be compatible with the relevant existing WMO code tables;

 

(b)   Code tables combining two or more existing WMO code tables to specify the units for an element which is defined, in the Manual on Codes, by a group of symbolic letters shall be compatible with the combined code figures of the relevant group of symbolic letters;

 

(c)   Code tables combining two or more existing WMO code tables to specify the units for an element which is defined, in the Manual on Codes, by different symbolic letters shall be compatible with the code figures of the relevant symbolic letters, with successive tens or hundreds values added, as different symbolic letters appropropriate;

 

(d)   Code tables and flag tables should only be used for reporting qualitative information. Quantitative information should be reported as observed using entries in Table B.  "Data description operators" from Table C should be applied when a "scale change" or "data width change" is required;

 

(e)  Reference to existing specification(s) and code table(s) in the Manual on Codes, with explanation of possible deviations, shall be given in an additional table annexed to the annexed  to the code tables associated with BUFR/CREX Table B.

 

 

 

 

 



0 20 003

 

Present weather

 

Code

figure

 

00-49

No precipitation at the station at the time of observation

00-19

No precipitation, fog, ice fog (except for 11 and 12), duststorm, sandstorm, drifting or blowing snow at the station* at the time of observation or, except for 09 and 17, during the preceding hour

No Meteors except photometeors

       00

Cloud development not observed or not observable

Characteristic change of the state of sky during the last hour

       01

Clouds generally dissolving or becoming less developed.

       02

State of sky on the whole unchanged.

       03

Clouds generally forming or developing

Haze, dust, sand or smoke

       04

Visibility reduced by smoke, e.g. veldt or forest fires, Industrial smoke or volcanic ashes

       05

Haze

       06

Widespread dust in suspension in the air, not raised by wind at or near the station at the time of observation

       07

Dust or sand raised by wind at or near the station at the time of observation, but no well-developed dust whirl(s) or sand whirl(s), and no duststorm or sandstorm seen; or, In the case of sea stations and coastal stations, blowing spray at the station

       08

Well-developed dust whirl(s) or sand whirl(s) seen at or near the station during the preceding hour or at the same time of observation, but no duststorm or sandstorm

       09

Duststorm or sandstorm within sight at the time of observation, or at the station during the preceding hour

10

Mist

11

Patches

shallow fog or ice fog at the station, whether on land or sea, not deeper than about 2 meters on land or 10 meters at sea

12

More or less continuous

13

Lightning visible, no thunder heard

14

Precipitation within sight, not reaching the ground or the surface of the sea

15

Precipitation within sight, reaching the ground or the surface of the sea, but distant, i.e. estimated to be more than 5 km from the station

16

Precipitation within sight, reaching the ground or the surface of the sea, near to, but not at the station

17

Thunderstorm, but no precipitation at the time of observation

18

Squalls

at or within sight of the station during the preceding hour or at the time of observation

19

Funnel cloud(s)**

 20-29

Precipitation, fog, Ice fog or thunderstorm at the station during the preceding hour but not at the time of observation

20

Drizzle (not freezing) or snow grains

not falling as shower(s)

21

Rain (not freezing)

22

Snow

23

Rain and snow or ice pellets

24

Freezing drizzle or freezing rain

25

Shower(s) of rain

26

Shower(s) of snow, or of rain and snow

27

Shower(s) of hail***, or of rain and hail***

28

Fog or Ice fog

29

Thunderstorm (with or without precipitation)

30-39

Duststorm, sandstorm, drifting or blowing snow

30

 

Slight or moderate duststorm or sandstorm

-          has decreased during the preceding hour

31

-          no appreciable change during the preceding hour

32

-          has begun or has increased during the preceding hour

33

Severe duststorm or sandstorm

-          has decreased during the preceding hour

34

-          no appreciable change during the preceding hour

35

-          has begun or has increased during the preceding hour

36

Slight or moderate drifting snow

generally low (below eye level)

37

Heavy drifting snow

38

Slight or moderate blowing snow

generally high (above eye level)

39

Heavy blowing snow

40-49

Fog or ice fog at the time of observation

40

Fog or ice fog at a distance at the time of observation, but not at the station during the preceding hour, the fog or ice fog extending to a level above that of the observer

41

Fog or ice fog in patches

42

Fog or ice fog, sky visible

has become thinner during the preceding hour

43

Fog or ice fog, sky invisible

44

Fog or ice fog, sky visible

no appreciable change during the preceding hour

45

Fog or ice fog, sky invisible

46

Fog or ice fog, sky visible

has begun or has become thicker during the preceding hour

47

Fog or ice fog, sky invisible

48

Fog, depositing rime, sky visible

49

Fog, depositing rime, sky invisible

50-99

Precipitation at the station at the time of observation

50-59

Drizzle

50

Drizzle, not freezing, intermittent

slight at time of observation

51

Drizzle, not freezing, continuous

52

Drizzle, not freezing, intermittent

moderate at time of observation

53

Drizzle, not freezing, continuous

54

Drizzle, not freezing, intermittent

heavy (dense) at time of observation

55

Drizzle, not freezing, continuous

56

Drizzle, freezing, slight

57

Drizzle, freezing, moderate or heavy (dense)

58

Drizzle and rain, slight

59

Drizzle and rain, moderate or heavy

60-69

Rain

60

Rain, not freezing, intermittent

slight at time of observation

61

Rain, not freezing, continuous

62

Rain, not freezing, intermittent

moderate at time observation

63

Rain, not freezing, continuous

64

Rain, not freezing, intermittent

heavy at time of observation

65

Rain, not freezing, continuous

66

Rain, freezing, slight

67

Rain, freezing, moderate or heavy

68

Rain or drizzle and snow, light

69

Rain or drizzle and snow, moderate or heavy

70-79

Solid precipitation not in showers

70

Intermittent fall of snowflakes

slight at time of observation

71

Continuous fall of snowflakes

72

Intermittent fall of snowflakes

moderate at time of observation

73

Continuous fall of snowflakes

74

Intermittent fall of snowflakes

heavy at time of observation

75

Continuous fall of snowflakes

76

Diamond dust (with or without fog)

77

Snow grains (with or without fog)

78

Isolated star-like snow crystals (with or without fog)

79

Ice pellets

80-99

Showery precipitation, or precipitation with current or recent thunderstorm

80

Rain shower(s), slight

81

Rain shower(s), moderate or heavy

82

Rain shower(s), violent

83

Shower(s) of rain and snow mixed, slight

84

Shower(s) of rain and snow mixed, moderate or heavy

85

Snow shower(s), slight

86

Snow shower(s), moderate or heavy

87

Shower(s) of snow pellets or small hail, with or without rain or rain and snow mixed

- slight

 

88

- moderate or heavy

89

Shower(s) of hail, with or without rain or rain and snow mixed, not associated with thunder

- slight

90

- moderate or heavy

91

Slight rain at time of observation

Thunderstorm during the preceding hour but not at time of observation

92

Moderate or heavy rain at time of observation.

93

Slight snow, or rain and snow mixed or hail*** at time of observation.

94

Moderate or heavy snow, or rain and snow mixed or hail*** at time of observation.

95

Thunderstorm, slight or moderate, without hail*** but with rain and/or snow at time of observation

Thunderstorm at time of observation.

96

Thunderstorm, slight or moderate, with hail*** at time of observation.

97

Thunderstorm, heavy, without hail***, but with rain and/or snow at time of observation.

98

Thunderstorm combined with duststorm or sandstorm at time of observation.

99

Thunderstorm, heavy, with hail*** at time of observation.

Present weather reported from an automatic weather station

100

No significant weather observed

101

Clouds generally dissolving or becoming less developed during the past hour

102

State of sky on the whole unchanged during the past hour

103

Clouds generally forming or developing during the past hour

104

Haze or smoke, or dust in suspension in the air, visibility equal to, or greater than, 1km

105

Haze or smoke, or dust In suspension in the air, visibility less than 1 km

106-109

Reserved

110

Mist

111

Diamond dust

112

Distant lightning

113-117

Reserved

118

Squalls

119

Reserved

Code figures 120-126 are used to report precipitation, fog (or ice fog) or thunderstorm at the station during the preceding hour but not at the time of observation

120

Fog

121

PRECIPITATION

122

Drizzle (not freezing) or snow grains

123

Rain (not freezing)

124

Snow

125

Freezing drizzle or freezing rain

126

Thunderstorm (with or without precipitation)

127

Blowing OR DRIFTING SNOW OR SAND

128

Blowing or drifting snow or sand, visibility equal to, or greater than, 1 km

129

Blowing or drifting snow or sand, visibility less than 1 km

130

FOG

131

Fog or ice fog In patches

132

Fog or ice fog, has become thinner during the past hour

133

Fog or ice fog, no appreciable change during the past hour

134

Fog or ice fog, has begun or become thicker during the past hour

135

Fog, depositing rime

136-139

Reserved

140

PRECIPITATION

141

Precipitation, slight or moderate

142

Precipitation, heavy

143

Liquid precipitation, slight or moderate

144

Liquid precipitation, heavy

145

Solid precipitation, slight or moderate

146

Solid precipitation, heavy

147

Freezing precipitation, slight or moderate

148

Freezing precipitation, heavy

149

Reserved

150

DRIZZLE

151

Drizzle, not freezing, slight

152

Drizzle, not freezing, moderate

153

Drizzle, not freezing, heavy

154

Drizzle, freezing, slight

155

Drizzle, freezing, moderate

156

Drizzle, freezing, heavy

157

Drizzle and rain, slight

158

Drizzle and rain, moderate or heavy

159

Reserved

160

RAIN

161

Rain, not freezing, slight

162

Rain, not freezing, moderate

163

Rain, not freezing, heavy

164

Rain, freezing, slight

165

Rain, freezing, moderate

166

Rain, freezing, heavy

167

Rain (or drizzle) and snow, slight

168

Rain (or drizzle) and snow, moderate or heavy

169

Reserved

170

SNOW

171

Snow, slight

172

Snow, moderate

173

Snow, heavy

174

Ice pellets, slight

175

Ice pellets, moderate

176

Ice pellets, heavy

177

Snow grains

178

Ice crystals

179

Reserved

180

SHOWER(S) or intermittent PRECIPITATION

181

Rain shower(s) or intermittent rain, slight

182

Rain shower(s) or intermittent rain, moderate

183

Rain shower(s) or intermittent rain, heavy

184

Rain shower(s) or intermittent rain, violent

185

Snow shower(s) or intermittent snow, slight

186

Snow shower(s) or intermittent snow, moderate

187

Snow shower(s) or intermittent snow, heavy

188

Reserved

189

Hail

190

THUNDERSTORM

191

Thunderstorm, slight or moderate, with no precipitation

192

Thunderstorm, slight or moderate, with rain showers and/or snow showers

193

Thunderstorm, slight or moderate, with hail

194

Thunderstorm, heavy, with no precipitation

195

Thunderstorm, heavy, With rain showers and/or snow showers

196

Thunderstorm, heavy, with hail

197-198

Reserved

199

Tornado

Present weather (In addition to present weather report from either a manned or an automatic station)

Decile 200-209

200

Not used

201

Not used

202

Not used

203

Not used

204

Volcanic ash suspended In the air aloft

205

Not used

206

Thick dust haze, visibility less than 1 km

207

Blowing spray at the station

208

Drifting dust (sand)

209

Wall of dust or sand in distance (like haboob)

Decile 210-219

210

Snow haze

211

Whiteout

212

Not used

213

Lightning, cloud to surface

214-216

Not used

217

Dry thunderstorm

218

Not used

219

Tornado cloud (destructive) at or within sight of the station during preceding hour or at the time of observation

Decile 220-229

220

Deposition of volcanic ash

221

Deposition of dust or sand

222

Deposition of dew

223

Deposition of wet snow

224

Deposition of soft rime

225

Deposition of hard rime

226

Deposition of hoarfrost

227

Deposition of glaze

228

Deposition of ice crust (ice slick)

229

Not used

Decile 230-239

230

Duststorm or sandstorm with temperature below 00C

231-238

Not used

239

Blowing snow, impossible to determine whether snow is falling or not

Decile 240-249

240

Not used

241

Fog on sea

242

Fog in valleys

243

Arctic or Antarctic sea smoke

244

Steam fog (sea, lake or river)

245

Steam log (land)

246

Fog over ice or snow cover

247

Dense fog, visibility 60-90 m

248

Dense fog, visibility 30-60 m

249

Dense fog, visibility less than 30 m

Decile 250-259

250

Drizzle, rate of fall

less than 0.10 mm h-1

251

0.10-0.19 mm h-1

252

0.20-0.39 mm h-1

253

O.40-0.79 mm h-1

254

O.80-1.59 mm h-1

255

l.60-3.19 mm h-1

256

3.20-6.39 mm h-1

257

6.4 mm h-1 or more

258

Not used

259

Drizzle and snow

Decile 260-269

 

260

Rain, rate of fall

less than 1.0 mm h-1

 

261

1.0-1.9 mm h-1

 

262

2.0-3.9 mm h-1

 

263

4.0-7.9 mm h-1

 

264

8.0-15.9 mm h-1

 

265

16.0-31.9 mm h-1

 

266

32.0-63.9 mm h-1

 

267

64.0 mm h-1 or more

 

268-269

Not used

 

Decile 270-279

 

270

Snow, rate of fall

less than 1.0 cm h-1

 

271

1.0-1.9 cm h-1

 

272

2.0-3.9 cm h-1

 

273

4.0-7.9 cm h-1

 

274

8.0-15.9 cm h-1

 

275

16.0-31.9 cm h-1

 

276

32.0-63.9 cm h-1

 

277

64.0 cm h-1 or more

 

278

Snow or Ice crystal precipitation from a clear sky

 

279

Wet snow, freezing on contact

 

Decile 280-299

 

280

Precipitation of rain

 

281

Precipitation of rain, freezing

 

282

Precipitation of rain and snow mixed

 

283

Precipitation of snow

 

284

Precipitation of snow pellets or small hall

 

285

Precipitation of snow pellets or small hail, with rain

 

286

Precipitation of snow pellets or small hail, with rain and snow mixed

 

287

Precipitation of snow pellets or small hail, with snow

 

288

Precipitation of hail

 

289

Precipitation of hail, with rain

 

290

Precipitation of hall, with rain and snow mixed

 

291

Precipitation of hail, with snow

 

292

Shower(s) or thunderstorm over sea

 

293

Shower(s) or thunderstorm over mountains

 

294-299

Not used

 

300-507

Reserved

 

508

No significant phenomenon to report, present and past weather omitted

 

509

No observation, data not available, present and past weather omitted

 

510

Present and past weather missing, but expected

 

511

Missing value

 














 

Notes:

 

(1)   The middle portion of this code table (code figures 100‑199) includes terms on several levels to cover simple and increasingly complex automatic stations.

 

(2)   Generic terms for weather (e.g. fog, drizzle) are intended for use at automatic stations capable of determining types of weather but no other information.  Generic terms are included in the code table using all capital letters.

 

(3)   Code figures for generic precipitation (code figures 140-148) are arranged in order of increasing complexity. For example, a very simple station that can sense only the presence or absence of precipitation would use code figure 140 (precipitation). At the next level, an automatic station capable of sensing amount but not type would use code figure 141 or 142. An automatic station capable of sensing gross type (liquid, solid, freezing) and amount would use code figures 143-148. An automatic station capable of reporting actual types of precipitation (e.g. drizzle rain), but not the amount, would use the appropriate whole decile number (e.g. 150 for generic drizzle, 160 for generic rain).



* The expression "at the station" refers to a land station or a ship.

** Tornado cloud or waterspout.

*** Hail, small hail, snow pellets



 

 

 

 

 

 

0 20 004 / 0 20 005

 

Past weather (l) and (2)

 

Code

figure

 

0

Cloud covering 1/2 or less of the sky throughout the appropriate period

1

Cloud coverIng more than 1/2 of the sky during part of the appropriate period and covering 1/2 or less during part of the period

2

Cloud covering more than 1/2 of the sky throughout the appropriate period

3

Sandstorm, duststorm or blowing snow

4

Fog or ice fog or thick haze

5

Drizzle

6

Rain

7

Snow, or rain and snow mixed

8

Shower(s)

9

Thunderstorm(s) with or without precipitation

10

No significant weather observed

11

Visibility REDUCED

12

Blowing phenomena, visibility reduced

13

FOG

14

PRECIPITATION

15

Drizzle

16

Rain

17

Snow or ice pellets

18

Showers or intermittent precipitation

19

Thunderstorm

20-30

Reserved

31

Missing value

 

Note:    The weather descriptions in code figures 10 to 19 are progressively complex, to accommodate the different levels of weather discrimination capability of various automatic stations. Stations having only basic sensing capability may use the lower code figures and basic generic descriptions (shown in capital letters).  Stations with progressively higher discrimination capability shall use the more detailed descriptions (higher codes).


 

 

 

 

 

0 20 008

 

Cloud distribution for aviation

 

Code

figure

 

 

0

Sky Clear

 

1

Few

 

2

Scattered

 

3

Broken

 

4

Overcast

 

5

Reserved

 

6

Scattered/Broken

(Many forecasts use Scattered/Broken or

7

Broken/Overcast

(Broken/Overcast followed by cloud type(s))

8

Isolated

(Used on aviation charts to describe the cloud type Cb)

9

Isolated embedded

(Used on aviation charts to describe the cloud type Cb)

10

Occasional

(Used on aviation charts to describe the cloud type Cb)

11

Occasional embedded

(Used on aviation charts to describe the cloud type Cb)

12

Frequent

(Used on aviation charts to describe the cloud type Cb)

13

Dense

(Used on aviation charts to describe cloud that would cause sudden changes in visibility (less than 1000m))

14

Layers

 

15

Obscured (OBSC)

 

16

Embedded (EMBD)

 

17

Frequent embedded (EMBD)

 

18-30

Reserved

 

31

Missing value

 


 

 

 

 

 

 

0 20 009

 

General weather indicator (TAF/METAR)

 

Code

figure

 

0

Reserved

1

NSC Nil Significant Cloud

2

CAVOK

3

SKC Sky Clear

4

NSW Nil Significant Weather

5-14

Reserved

15

Missing value


 

 

 

 

 

0 20 011

 

Cloud amount

 

Code

figure

 

 

0

0

0

1

1 okta or less, but not zero

1/10 or less, but not zero

2

2 oktas

2/10 - 3/10

3

3 oktas

4/10

4

4 oktas

5/10

5

5 oktas

6/10

6

6 oktas

7/10 - 8/10

7

7 oktas or more, but not 8 oktas

9/10 or more, but not 10/10

8

8 oktas

10/10

9

Sky obscured by fog and/or other meteorological phenomena

10

Sky partially obscured by fog and/or other meteorological phenomena

11

Scattered

12

Broken

13

Few

14

Reserved

15

Cloud cover is Indiscernible for reasons other than fog or other meteorological phenomena, or observation is not made

 

Notes:

 

(1)        For use of code figure 15, see Regulation 12.1.4.

(2)        `Clear' and `overcast' are coded by 0 and 8 respectively.


 

 

 

 

 

 

0 20 012

 

Cloud type

 

Code

figure

 

0

Cirrus (Ci)

1

Cirrocumulus (Cc)

2

Cirrostratus (Cs)

3

Altocumulus (Ac)

4

Altostratus (As)

5

Nimbostratus (Ns)

6

Stratocumulus (Sc)

7

Stratus(St)

8

Cumulus (Cu)

9

Cumulonimbus (Cb)

10

No CH clouds

11

Cirrus fibratus, sometimes uncinus, not progressively invading the sky

12

Cirrus spissatus, in patches or entangled sheaves, which usually do not increase and sometimes seem to be the remains of the upper part of a Cumulonimbus; or Cirrus castellanus or floccus

13

Cirrus spissatus cumulonimbogenitus

14

Cirrus uncinus or fibratus, or both, progressively invading the sky; they generally thicken as a whole

15

Cirrus (often in bands) and Cirrostratus, or Cirrostratus alone, progressively invading the sky; they generally thicken as a whole, but the continuous veil does not reach 45 degrees above the horizon

16

Cirrus (often In bands) and Cirrostratus, or Cirrostratus alone, progressively Invading the sky; they generally thicken as a whole; the continuous veil extends more than 45 degrees above the horizon, without the sky being totally covered

17

Cirrostratus covering the whole sky

18

Cirrostratus not progressively invading the sky and not entirely covering It

19

Cirrocumulus alone, or Cirrocumulus predominant among the CH clouds

20

No CM clouds

21

Altostratus translucidus

22

Altostratus opacus or Nimbostratus

23

Altocumulus translucidus at a single level

24

Patches (often Lenticular) of Altocumulus translucidus, continually changing and occurring at one or more levels

25

Altocumulus translucidus in bands, or one or more layers of Altocumulus translucidus or opacus, progressively Invading the sky;these Altocumulus clouds generally thicken as a whole

26

Altocumulus cumulogenitus (or cumulonimbogenitus)

27

Altocumulus translucidus or opacus In two or more layers, or Altocumulus opacus In a single layer, not progressively Invading the sky, or Altocumulus with Altostratus or Nimbostratus

28

Altocumulus castellanus or floccus

29

Altocumulus of a chaotic sky, generally at several levels

30

No CL clouds

31

Cumulus humilis or Cumulus fractus other than of bad weather*, or both

32

Cumulus mediocris or congestus, Towering cumulus (TCU), with or without Cumulus of species fractus or humilis or Stratocumulus, all having their bases at the same level

33

Cumulonimbus calvus, with or without Cumulus, Stratocumulus or Stratus

34

Stratocumulus cumulogenitus

35

Stratocumulus other than Stratocumulus cumulogenitus

36

Stratus nebulosus or Stratus fractus other than of bad weather*, or both

37

Stratus fractus or Cumulus fractus of bad weather*, or both (pannus),usually below Altostratus or Nimbostratus

38

Cumulus and Stratocumulus other than Stratocumulus cumulogenitus, with bases at different levels

39

Cumulonimbus capillatus (often with an anvil), with or without Cumulonimbus calvus, Cumulus, Stratocumulus, Stratus or pannus

40

CH

41

CM

42

CL

43-58

Reserved

59

Cloud not visible owing to darkness, fog, duststorm, sandstorm, or other analogous phenomena

60

CH clouds Invisible owing to darkness, fog, blowing dust or sand, or other similar phenomena, or because of a continuous layer of lower clouds

61

CM clouds Invisible owing to darkness, fog, blowing dust or sand, or other similar phenomena, or because of continuous layer of lower clouds

62

CL clouds invisible owing to darkness, fog, blowing dust or sand, or other similar phenomena

63

Missing value

 

*   "Bad weather" denotes the conditions which generally exist during precipitation and a short time before and after.


 

 

 

 

 

0 20 017

 

Cloud top description

 

Code

figure

 

 

0

Isolated cloud fragments of clouds

 

1

Continuous cloud

flat tops

2

Broken cloud - small breaks

3

Broken cloud - large breaks

4

Continuous cloud

undulating tops

5

Broken cloud - small breaks

6

Broken cloud - large breaks

7

Continuous or almost continuous waves with towering clouds above the top of the layer

8

Groups of waves with towering clouds above the top of the layer

9

Two or more layers at different levels

10-14

reserved

15

Missing value


 

 

 

 

 

0 20 018

 

Tendency of runway visual range

 

Code

figure

 

0

Increasing (U)

1

Decreasing (D)

2

No distinct change (N)

3

Missing value


 

 

 

 


0 20 021

 

Type of precipitation

 

Bit No.

 

1

Precipitation-unknown type

2

Liquid precipitation not freezing

3

Liquid freezing precipitation

4

Drizzle

5

Rain

6

Solid precipitation

7

Snow

8

Snow grains

9

Snow pellets

10

Ice pellets

11

Ice crystals

12

Diamond dust

13

Small hail

14

Hail

15

Glaze

16

Rime

17

Soft rime

18

Hard rime

19

Clear ice

20

Wet snow

21

Hoar frost

22

Dew

23

White dew

24-29

Reserved

All 30

Missing value

 

Note:    Mixed precipitation is indicated by setting to one the bits of all the observed single types of precipitation


 

 

 

 

 

0 20 022

 

Character of precipitation

 

Code figure

 

0

No precipitation

1

Continuous

2

Intermittent

3

Shower

4

Not reaching ground

5

Deposition

6-14

Reserved

15

Missing value


 

 

 


0 20 023

Other weather phenomena

 

Bit No.

 

1

Dust/sand whirl

2

Squalls

3

Sand storm

4

Dust storm

5

Lightning - cloud to surface

6

Lightning - cloud to cloud

7

Lightning - distant

8

Thunderstorm

9

Funnel Cloud not touching surface

10

Funnel cloud touching surface

11

Spray

 12 

Water-spout 

13

Wind shear

14

Dust devils

15-17

Reserved

All 18

Missing value


 

 

 

 

 

0 20 024

 

Intensity of phenomena

 

Code figure

 

0

No phenomena

1

Light

2

Moderate

3

Heavy

4

Violent

5

Severe

6

Very severe

7

Missing value


 

 

 

 

 

0 20 025

 

Obscuration

 

Bit No.

 

1

Fog

2

Ice fog

3

Steam fog

4-6

Reserved

7

Mist

8

Haze

9

Smoke

10

Volcanic ash

11

Dust

12

Sand

13

Snow

14

Cloud

15

Precipitation

16

Impossible to determine whether snow is falling or not

17-20

Reserved

All 21

Missing value


 

 

 


0 20 026

Character of obscuration

 

Code
figure

 

0

No change

1

Shallow

2

Patches

3

Partial

4

Freezing

5

Low drifting

6

Blowing

7

Increasing

8

Decreasing

9

In suspension in the air

10

Wall

11

Dense

12

Whiteout

13

Drifting and blowing

14

Reserved

15

Missing value


 

 

 

 

 

0 20 027

 

Phenomena* occurrence

 

Bit No.

 

1

At time of observation

2

In past hour

3

In time period for past weather W1W2

4

In time period specified

5

Reserved

6

Below station level

7

At the station (see Note 1)

8

In the vicinity (see Note 2)

All 9

Missing value

 

*   Phenomenon in 0 20 027 means any phenomenon, including precipitation and obscuration.

Notes:
(1) In conjunction with the observation of water spouts or funnel clouds i.e. within 3 km of station.
(2) In conjunction with the observation of water spouts or funnel clouds i.e. more than 3 km from station.


 

 

 

 

 

0 20 029

 

Rain flag

 

Code
figure

 

0

No rain

1

Rain

2

Reserved