Visibility/Weather Codes and Types (Met) Flashcards
BR
Mist
FG
Fog
BRFG
Patches of fog
MIFG
Shallow fog
SN
Snow
BLSN
Blowing snow
DRSN
Drifting snow
RA
Rain
DZ
Drizzle
HZ
Haze
VA
Volcanic Ash
DU
Dust
SA
Sand
FU
Fumes or smoke
Define ground visibility, and give an example of how it would be written in a METAR.
The greatest distance at which an accredited observer can see either a bright object at night, or a dark object against a bright background during the day. Either given as a 4 digit number in meters, e.g. 3000, or a 4 digit number, followed by a lower one and a direction, e.g. 2000 1000SW, meaning 2000m mostly, dropping to 1000 in the south west.
Define flight visibility, and the units it should be given in.
How far forwards you can see out of an aircraft in meters.
Define ground in sight visibility, and its units.
How high up you can be while seeing the ground if looking directly downwards from an aircraft, in meters.
Define runway visual range, and how it is measured. How is it presented in METARs?
Runway visual range is how far along the runway you can see, as measured by a transmissometer exactly 2m above ground level.
Presented as R1000, meaning RVR of 1000m, or RP 1000, meaning RVR of 1000m or more, or R1000V1300, which means RVR of 1000m, varying towards 1500m.
Define slant visibility.
The distance you can see looking forwards and 45 degrees downwards from the front of the plane.
Define vertical visibility, and give examples of how it can appear in a met report.
How far upwards you can see from the ground, in feet. Presented as VV004, which means vertical visibility 400ft, or VV000, which is vertical visibility less than 100ft, or VV///, which means stats unavailable.
FZRA
Freezing Rain
FZDZ
Freezing drizzle
PL
Ice pellets. Distinct from hail, because it melts and then freezes again on the way down.
SG
Snow grains (tiny snow)
GS
Small hail
+
heavy
-
light
GR
Hail
