1. IN THE NAME OF GOD SYNOPTIC METEOROLOGY CHAPTER ONE: METEOROLOGICAL STATIONS AND DATA SUMMER, 2011

2. Meteorological stations are used for observing meteorological parameters in the earth’s surface and upper of the atmosphere. The main surface-based stations are: (a)Surface synoptic stations: (i) Land stations: - Manned surface stations; - Automatic surface stations; Synoptic Meteorology (Chapter 1): METEOROLOGICAL STATIONS

3. (i) Sea stations: - Fixed sea stations: - Ocean weather stations; - Lightship stations; - Fixed platform stations; - Island and coastal stations; - Mobile sea stations: - ship stations; - Automatic sea stations: - Fixed stations - Mobile stations - Buoy stations Synoptic Meteorology (Chapter 1): METEOROLOGICAL STATIONS

4. (i) Upper-air synoptic stations: - Rawinsonde station; - Radiosonde station; - Radiowind station; (C) Aircraft Meteorological stations; (d) Climatological stations; (e) Agricultural meteorological stations; and (f) Special stations which include Weather radar stations, Radiation stations, Wind profilers and … Synoptic Meteorology (Chapter 1): METEOROLOGICAL STATIONS

5. Surface synoptic station may be manned or partly or fully automated and include land stations and fixed and mobile stations. Each synoptic station should be located so as to give meteorological data representative of the area in which it is situated. The main standard times foe surface synoptic observations are 0000, 0600, 1200 and 1800 UTC. The intermediate standard times for surface synoptic observations are 0300, 0900, 1500 and 2100 UTC. Synoptic Meteorology (Chapter 1): SURFACE SYNOPTIC STATIONS

6. The interval, in general, of surface synoptic stations should not exceed 250 km (or 300 km in sparsely populated areas). Surface synoptic observations recorded at a manned synoptic land station consist of observations of the following meteorological parameters: Present weather, Past weather, wind direction and speed, cloud amount, type of cloud, height of cloud base, visibility, air temperature, humidity, atmospheric pressure, Pressure tendency, Characteristic pressure tendency, Extreme temperature, Amount of precipitation, … Synoptic Meteorology (Chapter 1): SURFACE SYNOPTIC STATIONS

7. The standard times of upper-air synoptic observations should be 0000, 0600, 1200, 1800 UTC. An upper-air synoptic observations of one or more of the following meteorological elements: Atmospheric pressure, Air temperature, Humidity and Wind direction and Speed. Upper-air observations should be made and reported at least at 0000 UTC and 1200 UTC. Synoptic Meteorology (Chapter 1): UPPER-AIR SYNOPTIC STATIONS

8. The network of climatological stations give a satisfactory representation of all types of terrain in the territory of the concerned. At a principal climatological station, observations should be made of all or most of the following meteorological elements where appropriate: Weather, Wind direction and speed, Cloud amount, Type of cloud, Height of cloud base, Visibility, Air temperature (including extreme temperature), Humidity, Atmospheric pressure, Precipitation amount, Snow cover, Sunshine duration and/or solar radiation, Soil temperature (at 5, 10, 20, 50, 100, 150 and 300 cm). Synoptic Meteorology (Chapter 1): CLIMATOLOGICAL STATIONS

9. MiMiMjMjMiMiMjMj YYGGi w IIiiii R i X hVV Nddff1s n TTT2s n T d T d T d 3P 0 P 0 P 0 P 0 4PPPP5appp6RRRt R 7wwW 1 W 2 8N h C L C M C H 222//(0S n T W T W T W )1P Wa P Wa H Wa H Wa 2P W P W H W H w 3d w1 d w1 d w2 d w2 4P W1 P W1 H W1 H W1 5P W2 P W2 H W2 H W2 3331snTxTxTx1snTxTxTx 2snTnTnTn2snTnTnTn 3Ejjj 4E'sss5j1j2j3j47R 24 R 24 R 24 R 24 8N s Ch s h s Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

10. M i M i M j M j - Bulletin Header M i M i : For land station, this will be AA. It identifies the bulletin as being composed of “SYNOP” message from land station. M j M j : For land station, this will be XX. YYGGi w - Observation Date-Time Group YY : Day of the month of the observation. GG : Actual Time of the observation in UTC. i w : Wind speed indicator (code table 1855). Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

11. Code Table 1855 i w — Indicator for source and units of wind speed Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP Code Figure Description 0 Wind speed estimated, reported in meters per second. 1 Wind speed obtained from anemometer, reported in meters per second. 3 Wind speed estimated, reported in knots. 4 Wind speed obtained from anemometer, reported in knots. / Wind speed not available.

12. IIiii - International Index Number II : Block number. iii : Station number. i R i X hVV - Precipitation Inclusion-Exclusion / Type operation / Cloud height /Visibility Group i R : Indicator for inclusion or omission of precipitation data. Encoded using code table 1819. Code Table 1819 i R Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP CodePrecipitation data are recordedGroup 6RRRtR is: 0In Sections 1 and 3Included in both sections 1In Sections 1Included 2In Sections 3Included 3In neither section 1 or 3Omitted (precipitation amount = 0) 4In neither section 1 or 3Omitted (precipitation amount not available)

13. i X : Type of station operation indicator (manned or automatic) and whether group 7 is encoded in section 1. code table 1860 Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP CodeType of stationGroup 7wwW1W1 1MannedIncluded 2MannedOmitted (no significant phenomenon to report) 3MannedOmitted( no observation, data not available) 4AutomaticIncluded using code tables 4677 and 4561 5AutomaticOmitted (no significant phenomenon to report) 6AutomaticOmitted (no observation, data not available) 7AutomaticIncluded using code tables 4680 and 4531

14. h : Height above the surface of the base of the lowest cloud seen. Code table 1600 h Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP Code figure FeetMeters 00-1000-50 1100-300 50-100 2300-600100-200 3600-900200-300 4900-1900300- 600 51900-3200600-1000 63200-49001000-1500 74900-65001500-2000 86500-80002000-2500 98,000 or higher or no cloud2500 or higher or no cloud /Height of base of cloud is not known.

15. VV : Horizontal surface visibility The code is direct reading in units of 100 m from 0 to 50. The code figures 51 to 55 are not used. For code figures 56 to 80, 50 is subtracted and the remaining figure is direct reading in units of km. Code figures 90 to 99 are used to report visibility in the ship synoptic code. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

16. Nddff - Total cloud cover and wind group N : Total cloud cover. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP Code figureCloud amount (oktas)Cloud amount (tenths) 000 11/8 or less, not zero1/10 or less, not zero 22/82/10 - 3/10 33/84/10 44/85/10 55/86/10 66/87/10 – 8/10 77/8 or more but not 8/89/10 or more, but not 10/10 88/810/10 9Sky obscured, or cannot be estimated. /No measurement made

17. dd : True wind direction in tens of degrees, from which the wind is blowing. (Use code table 0877). For example 01 is used for 5° to 14° and 10 is used for 95° to 104° ff : Wind speed in units indicated by i w. Code Table 1855 i w Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP Code figureDescription 0Wind speed estimated, reported in meters per second. 1Wind speed obtained from anemometer, reported in meters per second. 3Wind speed estimated, reported in knots. 4Wind speed obtained from anemometer, reported in knots. /Wind speed not available.

18. 1s n TTT - Air Temperature Group 1 : Identifier for the air temperature group. s n : Sign of the temperature. 0 = temperature is positive or zero, 1 = temperature is negative. TTT : Air temperature in tenths of degrees Celsius. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

19. 2s n T d T d T d - Dew Point Temperature Group or Relative Humidity. 2 : Identifier for the dew point temperature group. s n : Sign of the dew point temperature. 0 = dew point temperature is positive or zero, 1 = dew point temperature is negative, 9 = relative humidity follows. T d T d T d : Dew point temperature in tenths of degrees Celsius. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

20. 3P 0 P 0 P 0 P 0 - Station Pressure Group 3 : Identifier for the station pressure group. P 0 P 0 P 0 P 0 : Pressure at station level, in tenths of a hPa. If the station pressure is more than 999.9 hPa, drop the thousands digit of the pressure. Example: station pressure = 1016.7 hPa P 0 P 0 P 0 P 0 = 0167 Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

21. 4PPPP : Sea Level Pressure Group 4 : Identifier for sea level pressure group. PPPP : Sea level pressure. This is the station pressure “reduced” to mean sea level in tenths of a hPa. If the sea level pressure is more than 999.9 hPa, the thousands digit of the pressure is omitted. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

22. 5appp - 3-Hour Pressure Tendency Group 5 : Identifier for the group reporting pressure tendency and pressure change for the three hours preceding the time of observation. a : Characteristic of the pressure tendency during the three hours preceding the time of the observation. Use code table 0200. ppp : Actual change in the pressure during the three hours ending at the actual time of the observation, expressed in tenths of hPa. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

23. Code Table 0200 Characteristic of Pressure Tendency (a) Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP 0 Increasing, then decreasing; atmospheric pressure the same or higher than 3 hours ago. 1 Increasing, then steady; or increasing, then increasing more slowly. Atmospheric pressure now higher than 3 hours ago. 2Increasing (steadily or unsteadily). 3 Decreasing or steady, then increasing; or increasing, then increasing more rapidly. 4Steady; atmospheric pressure the same as 3 hours ago. 5 Decreasing, then increasing; atmospheric pressure the same or lower than 3 hours ago. 6 Decreasing, then steady; or decreasing, then decreasing more slowly. Atmospheric pressure now lower than 3 hours ago. 7Decreasing (steadily or unsteadily) 8 Steady or increasing, then decreasing; or decreasing, then decreasing more rapidly.

24. 6RRRt R - Identifier for the precipitation group RRR : Total amount of precipitation fallen during the period preceding the time of observation, as indicated by t R. Code table 3590 Amount of precipitation Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP Code figureAmount (mm)Code figureAmount (mm) 000Not used990Trace 00119910.1 00229920.2 00339930.3 00449940.4 Etc. 9950.5 987 9960.6 988 9970.7 989 9980.8 9990.9

25. t R : Length of time covered by the group. Code table 4019 Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP Code figure Duration of period of precipitation 16 hours preceding time of observation 212 hours preceding time of observation 318 hours preceding time of observation 424 hours preceding time of observation 51 hour preceding time of observation. 62 hour preceding time of observation. 73 hour preceding time of observation. 89 hour preceding time of observation. 915 hour preceding time of observation.

26. 7wwW 1 W 2 - Present and Past Weather Group reported from an manned weather station. 7 : Identifier for the present and past weather group ww : Present weather at the time of the observation. W 1 W 2 : Past weather. The most significant and the second most significant past weather during the period. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP CodeCode table 4561 Past weather 0Cloud 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. 2Cloud covering more than 1/2 of the sky throughout the appropriate period. 3Sandstorm, dust storm, or blowing snow. 4Fog or ice fog or thick haze.7Snow, or rain and snow mixed. 5Drizzle.8Shower(s). 6Rain.9Thunderstorm(s) with or without precipitation.

27. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP Table 4677. ww

28. 8N h C L C M C H - Cloud Type Group 8 : Identifier of the type of cloud group. N h : Amount of low cloud present. Use code table 2700 with the Nddff group. C L : Clouds of the genera stratocumulus, stratus, cumulus, and cumulonimbus. Use code table 0513. C M : Clouds of the genera Altocumulus, Altostratus, and Nimbostratus. Use code table 0515. C H : Clouds of the genera Cirrus, Cirrocumulus, and Cirrostratus. Use code table 0509. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

29. Code table 0513 C L Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP CodeDiscription 0No C L clouds 1Cumulus humilis or cumulus fractus other than of bad weather,* or both. 2 Cumulus mediocris or congestus, with or without cumulus of species fractus or humilis or stratocumulus, all having their bases at the same level. 3Cumulonimbus calvus, with or without cumulus, stratocumulus or stratus. 4Stratocumulus cumulogenitus. 5Stratocumulus other than stratocumulus cumulogenitus. 6Stratus nebulosus or stratus fractus other than of bad weather, or both. 7Stratus fractus or cumulus fractus of bad weather. 8 Cumulus and stratocumulus other than stratocumulus cumulogenitus, with bases at different levels. 9 Cumulonimbus capillatus (often with an anvil), with or without cumulonimbus calvus, cumulus, stratocumulus, stratus or pannus. /CL clouds invisible owing to darkness, fog, blowing dust or sand, or ….

30. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP Code table 0515 C M CodeDiscription 0No C M clouds 1Altostratus translucidus 2Altostratus opacus or nimbostratus 3Altocumulus translucidus at a single level. 4 Patches (often lenticular) of altocumulus translucidus, continually changing and occurring at one or more levels. 5Altocumulus translucidus in bands. 6Altocumulus cumulogenitus (or cumulonimbogenitus) 7Altocumulus translucidus or opacus in two or more layers. 8Altocumulus castellanus or floccus. 9Altocumulus of a chaotic sky, generally at several levels. / CM clouds invisible owing to darkness, fog, blowing dust or sand, or other similar phenomena, or because of continuous layer of lower clouds.

31. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP CodeDiscription 0No C H clouds 1Cirrus fibratus, sometimes uncinus, not progressively invading the sky. 2Cirrus spissatus, in patches or entangled sheaves. 3Cirrus spissatus cumulonimbogenitus. 4Cirrus uncinus or fibratus, or both, progressively invading the sky. 5 Cirrus (often in bands) and cirrostratus, or cirrostratus alone, progressively invading the sky. 6 Cirrus (often in bands) and cirrostratus, or cirrostratus alone, progressively invading the sky; they generally thicken as a whole;. 7Cirrostratus covering the whole sky. 8Cirrostratus not progressively invading the sky and not entirely covering it. 9Cirrocumulus alone, or cirrocumulus predominant among the C H clouds. / C H clouds invisible owing to darkness, fog, blowing dust or sand, or other similar phenomena, or because of a continuous layer of lower clouds. Code table 0509 C H

32. 222// - Section 2 Identifier Group for Reporting Wind and Swell Waves (0S n T W T W T W ) - Sea-surface temperature group. 0 : Identifier for sea-surface temperature group. sn : Sign of the temperature: 0 = temperature is positive or zero; 1 = temperature is negative. T W T W T W : Sea-surface water temperature given in units of tenths of degree Celsius. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

33. 1P Wa P Wa H Wa H Wa - Instrumental wave data group. 1 : Identifier for the instrumental wave data group. P Wa P Wa : Period of the waves obtained by instrumental methods, in whole seconds. H Wa H Wa : Height of waves, obtained by instrumental methods, in units of 0.5 meters. See wave height table below. 2P W P W H W H W - Wind Wave Group. This group is used to report wind waves when instrumental wave data is not available. The period and wave heights are estimated. 2 : Identifier for the non-instrumental wind wave group. P W P W : Estimated period of the wind wave in whole seconds. H W H W : Estimated height of the wind waves in units of half- meters. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

34. 3d w1 d w1 d w2 d w2 - Swell Wave Direction Group 3 : Identifier for the swell wave direction group. d w1 d w1 : The true direction, in tens of degrees from which the first swell wave system is moving. Code table 0877 is used. d w2 d w2 : The true direction, in tens of degrees from which the second swell wave system is moving. Code table 0877 is used. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

35. 4P W1 P W1 H W1 H W1 - First Swell System Group 4 : Identifier for the first swell system group. P W1 P W1 : Period of the first swell system in whole seconds. H W1 H W1 : Average height of the significant swell waves of the first swell system reported in half-meters. 5P W2 P W2 H W2 H W2 - Second Swell Wave System Group 5 : Identifier for the second swell wave system group. P W2 P W2 : Period of the second swell wave system in whole seconds. H W2 H W2 : Average height of the significant swell waves of the second swell system. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

36. 333 - Group Identifier for Section 3 1s n T x T x T x - Maximum Temperature Group. 1 : Identifier for the maximum temperature group. s n : Sign of the temperature. 0 = positive or zero maximum temperature. 1 = negative maximum temperature. T x T x T x : Maximum temperature in tenths of degrees Celsius. 2s n T n T n T n - Minimum Temperature Group s n : Sign of the temperature. 0 = positive or zero; 1 = temperature is negative. T n T n T n : Minimum temperature in tenths of degrees Celsius. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

37. 7R 24 R 24 R 24 R 24 - 24-Hour Precipitation Group 7 : Identifier for the 24-hour precipitation group. R 24 R 24 R 24 R 24 : Precipitation amount for the past 24 hours. The total amount of liquid precipitation and the water equivalent for solid precipitation is encoded to the nearest tenths of millimeters. It is coded 79998 for 999.8 mm or more, and if only a trace has fallen, encode 79999. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP

38. 8N s Ch s h s - Individual Cloud Layer Group 8 : Identifier for the individual cloud layer group. The group may be repeated up to three times (four if one layer is cumulonimbus) in one report. N s : The amount of the individual cloud layer reported. Use code table 2700. See the table with the Nddff group. C : Cloud type for the layer. Use code table 0500. h s h s : Height above the ground of the base of the cloud layer. Use code table 1677. Synoptic Meteorology (Chapter 1): LAND STATION SURFACE SYNOPTIC CODE FM 12-IX SYNOP