The additive data, supplemental data, remarks
about RVR, and runway conditions as used in the
METAR/SPECI code at shore stations are NOT used by
What column on CNMOC Form 3141/3 is used
to record remarks?
What column is used to record sea surface
What column is used to recordsea wave height?
What publication provides detailed instructions
for taking and recording ship observations
aboard U.S. Navy ships?
LEARNING OBJECTIVES: Identify the
manuals that provide instruction on encoding
and decoding land and ship synoptic
observations. Explain the meaning of each
code figure in the land and ship synoptic code.
Describe the code used to relay reports from
moored coastal observation buoys.
Where the METAR/SPECI codes are designed to
report aviation weather, the Synoptic code is
specifically designed to include data for use in
analyzing the current overall weather situation. It is a
numerical code that consists mostly of groups of five
digits, specifically designed. to permit automatic
loading of computer data bases.
The Synoptic reports are transmitted by selected
stations worldwide at 0000Z, 0600Z, 1200Z, and
1800Zthe "Synoptic Hours"with the reports
generally called "Main Synoptic" reports. Significant
reports called "Intermediate Synoptic" reports may be
transmitted at the "Intermediate Synoptic" hours:
0300Z, 0900Z, 1500Z, and 2100Z.
Although the Synoptic code transmitted by land
stations and by ships report many of the same weather
elements by using the same symbolic groups, there are
some differences in the way the station is identified.
There are also different types of data that are only
reported by land stations, just as there is some data that
is only reported by ships.
The primary reference manual used to encode
weather elements observed during an aviation hourly
weather observation at land stations into land Synoptic
codes is the Federal Meteorological Handbook No. 2
(FMH-2), Surface Synoptic Codes. This publication
describes which elements are encoded, and also covers
supplemental data, which is added to the International
code form as Regional data in WMO Region IV
North America, (and U.S. stations in WMO Region V
Central and Southern Pacific, including Hawaii,
Guam, and the Philippines). It also includes National
Data, which is added to the code in the United States.
The primary reference used when encoding
weather observations into the ship Synoptic code is
NAVMETOCCOMINST 3144.1, United States Nary
Manual for Ship'.s Surface Weather Observations,
although the FMH-2 also provides guidance on the ship
Synoptic code. The publications that are most useful in
decoding Synoptic reports received from overseas
stations are the WMO Publication 306, Manual on
Codes, Volume 1, International Codes, and Volume 2,
Regional Codes and National Coding Practices. The
International Codes provides symbolic formats for all
of the International codes, an alphabetical listing of
each symbolic element, with an explanation of each
code element and reference to the appropriate code
table, as well as a section providing all of the WMO
In the following text, we discuss the land Synoptic
code, the ship Synoptic code, and the code used to relay
reports from moored coastal observation buoys. Most
of the applicable code tables are listed in Appendix IV.
First, let's consider the land Synoptic code.
LAND SYNOPTIC CODE
In addition to reporting surface aviation hourly
observations, many Navy and Marine Corps land
stations, both in the United States and overseas, also
report Synoptic weather observations in WMO Code
FM 12-XI SYNOP.
Table 3-5 provides a breakdown of the symbolic
code format of the land Synoptic code. Only those
groups considered significant are included in a report.
If the type of data the code group requires is not
normally available at a station, the entire group is not
reported. A solidi (forward-slash /) is used in place of
each number that is normally reported, but is
unobservable because of weather conditions or