Since all observations are entered into the climatic data
base, errors on the observation form should be corrected
even if discovered too late to provide timely and
accurate information to aircraft and ships. You should
correct errors in the following three ways:
If an error has not been transmitted, erase and
reenter data correctly.
If an error is discovered after transmission, line
out the error, enter the correction in red, transmit
the correct data, and then enter the correction
time, which is the time of transmission of the
If an error has been transmitted but superseded
with a later observation, simply line out and enter
the correction in red.
See NAVMETOCCOMINST 3141.2 or
NAVMETOCCOMINST 3144.1 for additional details
on entering corrected data. To help reduce errors, all
data should be reviewed by another qualified observer.
Most sites have an established quality control person
who routinely reviews the observation forms. Other
than the observer, the quality control person is the only
individual who may be authorized to make corrections
to an observation record.
MAILING OF RECORDS
At the end of each month, the original observation
forms are forwarded to the Fleet Numerical
Meteorology and Oceanography Detachment,
Asheville, North Carolina. Refer to NAVMETOC-
COMINST 3141.2 or NAVMETOCCOMINST 3144.1
for detailed information on mailing observation forms.
Additional information is also contained in
NAVMETOCCOMINST 3140.1, U.S. Navy
Meteorological and Oceanographic Support System
Manual, and FNMODASHEVILLENOTE 3140,
Procedures for Submitting Meteorological Records.
The observation forms are microfiched at Asheville,
and the information is included in the National Climatic
Records data base. Duplicate copies of the observation
forms may be retained on board until no longer needed;
however, most sites retain the duplicate copies for at
least 1 year.
After recording the observation, it must be encoded
for local and/or longline (regional or national)
dissemination. In the next section, we will discuss the
codes used for dissemination purposes.
How should missing data be indicated on
What is the primary purpose of collecting and
transmitting weather data?
Q8. How is an observation error corrected on an
observation form after the observation has been
Where are observation forms mailed at the end
of each month?
SURFACE AVIATION WEATHER
LEARNING OBJECTIVES: Identify the
applications of the format of the METAR and
SPECI codes. Describe the elements of the
METAR and SPECI codes and define the
meaning of each element.
The METAR code is an International Observation
code used to record and disseminate routine surface
aviation weather observations. The SPECI code is a
related International code used to record and
disseminate selected surface aviation weather
observations marking significant changes in the
weather conditions. It is used to supplement the hourly
observations in the METAR code.
The METAR and SPECI codes discussed in this
section are used by all Navy and Marine Corps activities
worldwide and are a modified version of the WMO
METAR and SPECI codes used by most of the other
countries in the world.
As previously mentioned, the primary reference
manuals for Navy and Marine Corps activities are
NAVMETOCCOMINST 3141.2 and NAVMETOC-
COMINST 3144.1. You, as an observer, must be
thoroughly familiar with these instructions. We will
now discuss the encoding of the individual elements of a
TYPES OF OBSERVATIONS
In METAR, there are only two types of
Routine observations (METAR)routine
observations, taken each hour on the hour. The
observation time is noted when the last element was