Page 14 - AFMAN 15-111, 12 MAR 2019

14 AFMAN15-111 12 MARCH 2019

3.5.2.4. Location Entries. Phenomena encoded in the body of the report as vicinity (VC)
may be further described (e.g., direction from the observing location) in the remarks.
Phenomena occurring beyond, or thought to be beyond, 10 statute miles (SM) of the point
of observation may be reported as distant (DSNT) followed by the direction from the
observing location. If known, the distance may be included in the remark. In the case of a
tornado, the exact location should be included when possible.
3.5.2.5. Movement Entries. Movement of clouds or weather, if known, will be encoded
with respect towards the direction the phenomenon is moving. (T-0). For example, a
thunderstorm 9SM north moving toward the northeast would be encoded as “TS 9N MOV
NE.”
3.5.2.6. Direction. Directions will use the eight points of the compass encoded in a
clockwise order beginning with north. (T-0). In the event that the reported phenomena is
north but also extends northwest and northeast, record the phenomena in a clockwise
direction (e.g., TS 10NW-NE).

3.6. Observation Methods.
3.6.1. Automated Observations. FBWOSs use time averaging of sensor data. Sky condition is
an evaluation of sensor data gathered during the 30-minute period ending at the actual time of
the observation. All other elements evaluated are based on sensor data that is within 10 minutes
or less of the actual time of the observation. For objective elements such as pressure,
temperature, dew point, and wind, automated and augmented observations use a fixed location
and time-averaging technique. For subjective elements such as sky condition, visibility, and
present weather, a FBWOS uses a fixed location, time-linear technique. Some FBWOSs are
capable of generating an observation every minute; the One-Minute Observation (OMO) is
encoded in METAR format and includes all of the basic weather parameters found in the body
of the METAR plus specific automated remarks. The OMO also accepts augmented elements
and remarks. The difference between the OMO and the METAR/SPECI is that the OMO is not
normally disseminated. The weather technician can manually disseminate the OMO if
required, for example, upon arrival at an AOL.
3.6.2. Augmented Observations. A fixed time, spatial averaging technique is used to evaluate
subjective elements (i.e. sky condition, visibility, etc.) in augmented observations. Individual
elements entered must reflect conditions existing at the actual time of observation. Observation
of elements will be made as close to the scheduled time of the observation as possible to meet
filing deadlines, but in no case will these observations be started more than 15 minutes before
the scheduled time. (T-1). Supplement elements evaluated instrumentally with visual
observations to ensure accuracy.
3.6.2.1. Order of Observing. Elements having the greatest rate of change are evaluated
last. When conditions are relatively unchanging, evaluate outdoor elements first, followed
by indoor elements with pressure being last.
3.6.2.2. Before taking observations at night, spend as much time as practicable outside to
allow your eyes to adjust to lower light conditions.