IRFP-01
Metro Review
d. Symbology
Fig 18: Standard
Chart Symbols
(1) Standard symbols depict fronts
(2) “H” or “L” and isobars denote pressure systems
(3) Station model includes information on sky coverage, wind
Fig 19: Major Station
direction and speed, temperature, dew point, precipitation,
Model Symbols
and other related information
2. Weather depiction charts 21.1.1.3.3
Fig 20: Weather
Depiction Chart
a. Compiled from hourly surface aviation reports
b. Quickly identify positions of fronts and areas of VFR, marginal
VFR (MVFR), and IFR weather
(1) MVFR (marginal visual flight rules) weather between 1,000
ft ceiling/3 miles visibility and 3,000 ft ceiling/5 miles
visibility
(2) MVFR has no bearing on the civilian or military pilot but
warns of poor flying conditions
(3) Chart contains a legend for clarity
c.
Disseminated 8 times a day, every 3 hours starting at 0100Z
d. Symbology
(1) Standard symbols depict fronts (as on surface analysis
chart)
(2) Contoured unshaded areas indicate MVFR weather with
ceilings of 1,000-3,000 ft AGL and/or visibilities of 3-5 sm
(3) Contoured shaded areas indicate IFR weather with ceilings
of less than 1,000 ft AGL and/or visibility of less than 3 sm
(4) The weather depiction chart station model contains no
wind, temperature, or pressure information.
NOTE: The following items are depicted: sky coverage,
height of lowest cloud layer (or ceiling height, if present) in
ft AGL, visibility if 6 sm or less, and form of weather
obscuring the visibility (as in Figure 20).
(5) Sky coverage symbols are different from those used for
the surface analysis charts
(6) Some weather symbols used on the surface analysis are
used on the weather depiction chart
(8-97) Original
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