Visibility/Weather Codes and Types (Met)

Question 1

BR

Answer 1

Mist

Question 2

FG

Answer 2

Fog

Question 3

BRFG

Answer 3

Patches of fog

Question 4

MIFG

Answer 4

Shallow fog

Question 5

SN

Answer 5

Snow

Question 6

BLSN

Answer 6

Blowing snow

Question 7

DRSN

Answer 7

Drifting snow

Question 8

RA

Answer 8

Rain

Question 9

DZ

Answer 9

Drizzle

Question 10

HZ

Answer 10

Haze

Question 11

VA

Answer 11

Volcanic Ash

Question 12

DU

Answer 12

Dust

Question 13

SA

Answer 13

Sand

Question 14

FU

Answer 14

Fumes or smoke

Question 15

Define ground visibility, and give an example of how it would be written in a METAR.

Answer 15

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.

Question 16

Define flight visibility, and the units it should be given in.

Answer 16

How far forwards you can see out of an aircraft in meters.

Question 17

Define ground in sight visibility, and its units.

Answer 17

How high up you can be while seeing the ground if looking directly downwards from an aircraft, in meters.

Question 18

Define runway visual range, and how it is measured. How is it presented in METARs?

Answer 18

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.

Question 19

Define slant visibility.

Answer 19

The distance you can see looking forwards and 45 degrees downwards from the front of the plane.

Question 20

Define vertical visibility, and give examples of how it can appear in a met report.

Answer 20

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.

Question 21

FZRA

Answer 21

Freezing Rain

Question 22

FZDZ

Answer 22

Freezing drizzle

Question 23

PL

Answer 23

Ice pellets. Distinct from hail, because it melts and then freezes again on the way down.

Question 24

SG

Answer 24

Snow grains (tiny snow)

Question 25

GS

Answer 25

Small hail

Question 26

+

Answer 26

heavy

Question 27

-

Answer 27

light

Question 28

GR

Answer 28

Hail