Training Guide in Surface Weather Observations - Multiple Choices

3.2.3 Surface and Tower Visibility
Surface visibility and tower visibility differ only in the point of observation. Surface visibility is the
prevailing visibility reported from the usual point of observation. At some locations, this point may even
be the control tower. Tower visibility is the prevailing visibility taken from the control tower when there
is another site from which the surface visibility is determined.
One of the more difficult problems in reporting and recording visibility is that of surface and tower
visibility. To clarify the procedures, let’s look at the recording procedures first and then the reporting
procedures.
Visibility at the usual point of observation (surface) is always reported in the observation and, therefore,
is always recorded in column 7(a), MF1M-10.
Record tower visibility in column 7(b) when it is less than 4 miles and differs from the surface visibility;
also enter the higher visibility value (SFC or TWR) in column 14, Remarks. Do not make an entry in
column 7(b) if tower visibility is equal to the surface visibility (see Figures 3-5 through 3-9).
In the coded transmitted report, the lower visibility value is reported in the body and the higher visibility
in the remarks section of all observations. Several examples follow:
SUR-
FACE
VISIBILITY PRESENT
WEATHER
TOWER RUNWAY VISUAL
RANGE
(Feet)
Figure 3-5. Surface Visibility 2SM
SKY CONDITION TEMP.
(°C)
3-3
DEW
POINT
(°C)
ALTIMETER
SETTING
(Ins.)
REMARKS AND SUPPLEMENTAL CODED DATA
(7a) (7b) (8) (9) (10) (11) (12) (13) (14)
2
Since the tower visibility is 4 statute miles or greater, no entry is required for tower visibility. 2SM
would be reported in the body of the transmitted report.