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- SECTION 0

iii iRixhVV

- SECTION 1

Nddff 1snTTT 2snTdTdTd 4PPPP 5appp 6RRRtR 7wwW1W2 8NhCLCMCH

- SECTION 3

333 1snTxTxTx (at 1800 UTC) 2snTnTnTn (at 0600 UTC) 3EsnTgTg (at 0600 UTC) 4E'sss (at 0600 UTC) 8NsChshs 9SpSpspsp

- SECTION 5

555 1V'f'/V'f''f'' 2snTwTwTw iiirrr

Interpretation

- SECTION 0

iii Station Number
iRixhVV  
iR Inclusion or omission of precipitation data
ix Inclusion or omission of weather group
h Height of base of lowest cloud
VV Horizontal visibility

 

- SECTION 1

Nddff  
N Total Cloud amount
dd Wind direction in tens of degrees
ff Wind speed in knots
1snTTT  
1 Indicator
sn Sign of temperature
TTT Dry-bulb temperature in tenths of a degree Celsius
2snTdTdTd  
2 Indicator
sn Sign of temperature
TdTdTd Dew-point temperature in tenths of a degree Celsius
4PPPP  
4 Indicator
PPPP Last four figs. of air pressure (reduced to mean sea level) in millibars and tenths
5appp  
5 Indicator
a Characteristic of pressure change
ppp Pressure change over last three hours in millibars and tenths
6RRRtR  
6 Indicator
RRR Amount of rainfall
tR Duration of period of RRR in units of six hours. Main hours only, so at 0001 and 1200 UTC tR=1 At 0600 and 1800 tR=2
7wwW1W2  
7 Indicator
ww Present weather, manned station
W1W2 Past weather, manned station
8NhCLCMCH  
8 Indicator
Nh Amount of low cloud, or medium cloud if no low cloud present
CL Form of low cloud
CM Form of medium cloud
CH Form of high cloud

 

- SECTION 3

333 Regional Indicator
1snTxTxTx  
1 Indicator
sn Sign of temperature
TxTxTx Maximum temperature 0600-1800 UTC in tenths of a degree
2snTnTnTn  
2 Indicator
sn Sign of temperature
TnTnTn Minimum temperature 1800-0600 UTC in tenths of a degree
3EsnTgTg  
3 Indicator
E State of ground without snow or measurable ice cover
sn Sign of temperature
TgTg Grass minimum temperature rounded to nearest whole degree
4E'sss  
4 Indicator
E' State of ground with snow or measurable ice cover
sss Depth of snow
8NsChshs  
8 Indicator
Ns Amount of individual cloud layer
C Form of cloud (Table 19)
hshs Height of base of cloud layer
9SpSpspsp  
9 Indicator
SpSpspsp This group is included when necessary to report special phenomena.

General information:
Up to four layers of significant cloud can be reported (using 8NhChshs groups). The rules for the selection of significant cloud layers are:
1. The lowest layer of any amount
2. The next lowest layer of 3 oktas (eighths) or more.
3. The next lowest layer of 5 oktas or more.
4. Any cumulonimbus cloud not already reported under 1, 2 or 3 above, regardless of amount.

Clouds are reported in order of ascending height. Cumulonimbus cloud reported under rule 4 above would be inserted between the other groups at its correct height level - regardless of the amount of Cumulonimbus being reported.

 

- SECTION 5

555 National indicator (This section is not sent when there are no data to report)
1V'f'/V'f''f''  
1 Indicator
V'V' Visibility in metres (reported when visibility is less than 100 m)
(f')f'f' Speed in knots of the maximum gust in the past hour (>33 kts)
2snTwTwTw  
2 Indicator
sn Sign of temperature
TwTwTw Sea temperature in tenths of a degree

 


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