Synop Bulletin

SYNOP (surface synoptic observations) is a numerical code used for reporting weather observations made by manned and automated weather stations.

It isn't a Aeronautical Bulletin but is a Statistic Bulletin.

SYNOP reports are typically sent every six hours.

This Bulletin contain information about visibility, ceiling, clouds and pressure and AWOS systems are able to compile automatically.   

Synop Format:

This is the general structure of a SYNOP message. Numbers shown here are fixed (group indicators), numbers replacing the x's contain the weather data plus information about the station's position (and speed and direction where applicable).

xxxxx xxxxx 99xxx xxxxx xxxxx xxxxx 00xxx 1xxxx 2xxxx 3xxxx 4xxxx 5xxxx
6xxxx 7xxxx 8xxxx 9xxxx 222xx 0xxxx 1xxxx 2xxxx 3xxxx 4xxxx 5xxxx 6xxxx
70xxx 8xxxx
  333 0xxxx 1xxxx 2xxxx 3xxxx 4xxxx 5xxxx xxxxx 6xxxx 7xxxx 8xxxx 9xxxx

Example

AAXX	13064	16194	41660	80502	10235	20140	40086	57007
	78082	8693/	333	20201	30020	82930	85635

How read:

Code	Symbol	Significance
AAXX	MiMiMjMj	SYNOP Bulletin
13064	YYGGIw	day 13 at 06 UTC Wind is observed by anemometer (Iw=4)
16194	IIiii	On the Italian, Greek or Maltese station  (16) number 194
41660	IrIxhVV	There are no data about precipitation because reading is not executed  (Ir=4) The station is manned by staff (not automatic) in the first section contains data about the present and past (Ix = 1) The base of low clouds is between 1000 and 1500 meters ( h=6 ) Minimum Visibility is 10 Km ( VV=60 )
80502	Nddff	Sky coverage is 8/8 ( N=8 ) Wind direction = 50°           Wind speed = 2 KN (ddff = 0502 )
10235	1SnTTT	Air Temperature = +23,5°C
20140	2SnTdTdTd	Dew Point = +14,0°C
	3PoPoPoPo	Atmospheric Pressure = N.A.
40086	4PPPP	QNH = 1008,6 hPa
57007	5appp	The barometric trend is decreased and the pressure change in thelast three hours was 0.7 hPa
	6RRRtr	Precipitation = N.A
78082	7wwW1W2	Weather Condition : light rain ( -RA) and in the last three hours occurredshowers (2= Not Significant Data )
8693/	8NhClCmCh	Cloud Coverage : consists of 6/8 of low clouds type ofcumulonimbus anvil with presence of high and undetectable altocumulus clouds
333		Section number 3
20201	2SnTnTnTn	Minimum Temperature was 20,1°C
32020	3ESnTgTg	Ground Status = wet
82930	8NsChshs	Other Clouds CB with coverage equal to 2/8
85635	8NsChshs	Other Clouds : SC  with coverage equal to  6/8