Page 53 - AFMAN 15-111, 12 MAR 2019

AFMAN15-111 12 MARCH 2019 53

10.7.3. Other Phenomena are meteorological events that do not necessarily directly reduce
visibility but are of enough significance that they warrant reporting in an observation when
they are in the area (i.e. on-station, in the vicinity, or distant). When applicable, additional
information describing the nature of the phenomena is included in column 13 remarks
following the guidance in Attachment 3.

10.7.3.1. Well-Developed Dust/Sand Whirl (PO): Dust or sand that is raised from the
ground and takes the form of a whirling column with varying height, small diameter and
an approximate vertical axis. Commonly referred to as “Dust Devils,” they typically form
in dry regions on hot, calm days when intense surface heating causes a very steep
temperature lapse rate in the lower levels of the atmosphere; may be strong enough to cause
wind damage.

10.7.3.2. Squall (SQ): A strong wind event characterized by a sudden increase in speed of
at least 16 kts with sustained speeds of at least 22 kts for at least 1 minute.
10.7.3.3. Funnel Cloud (FC): A funnel shaped mass of moisture and/or debris associated
with a violent, rotating column of air. Funnel clouds usually form as pendants from
cumulonimbus clouds and may be observed over land or water but do not touch the surface.
Can be confused with scud/inflow bands which appear similar in appearance but do not
rotate.
10.7.3.4. Tornado/Water Spout (+FC): A funnel shaped mass of moisture and/or debris
associated with a violent, rotating column of air that does touch the surface. Regardless of
where they form or move, this phenomenon is reported as a Tornado while over land and
a Water Spout while over water; both are encoded as +FC.

10.7.3.5. Dust storm (DS): An unusual, frequently severe weather condition characterized
by strong winds and dust-filled air that can reduce visibility over an extensive area, often
preceded by a wind driven dust wall that can exceed 3,000ft in vertical extent.

10.7.3.6. Sandstorm (SS): A wind driven event, typically occurring during the heat of the
day and dying out at night, where particles of sand are lifted enough to cause a reduction
in visibility. Unlike a DS, the sand is mostly confined to the lowest 10ft and rarely rises
more than 50ft above the ground.
10.8. Manual Observing

10.8.1. Present weather is determined through physical observation and by using a
combination of the Qualifiers, Precipitation Types, Obscurations, and Other Phenomena
described above. These elements, combined with prevailing and sector visibility, dictate what
present weather is encoded.

10.8.2. When observed to be occurring on station, all forms of precipitation will be reported.
(T-1). Use Table 10.4 to determine precipitation intensity (applicable intensity qualifier) based
on rate-of-fall, accumulation characteristics, and/or visibility. If in the vicinity, should be
reported using the VC qualifier; in this case, no intensity is assigned. If precipitation is
observed to be occurring beyond 10SM of the observation point, may be reported in column
13 remarks as distant.