Non-Graphic Weather Flashcards
Define prevailing visibility
Greatest distance at which objects can be seen and identified through at least half the horizon circle, which need not be continuous.
Where is Runway Visual Range (RVR) measured from?
RVR is measured from touchdown point of the runway.
When is RVR reported?
When visibility is less than 1 SM and/or visibility is 6,000 FT or less
What does the acronym CAVOK stand for and what does the term mean?
Ceiling and Visibility OK
- Visibility is 10 KM or more
-No clouds below 5,000 FT
-There are no cumulonimbus clouds
-No specific weather phenomena
What does ALQDS mean?
All quadrants
How are significant weather changes in a METAR disseminated?
A SPECI (non-routine aviation report) is issued
What is calm wind on a METAR?
less than 3 KTS
What is calm wind on a TAF?
3 KTS or less
Define Gust
a variation in wind speed of at least 10 KTS
What is VC and what is it applied to?
VC= Vicinity
Between 5 and 10 SM of the point of observation
Define BL?
Blowing.
Shall be used when dust, sand, snow is raised by the wind to a height of 6 FT or more
Define DR
Drifting
Shall be used when dust, sand, snow is raised by the wind to a height of less than 6 FT
Define Precipitation
Any form of water particles, whether solid or liquid, that fall from the atmosphere and reach the ground
When is a SPECI issued?
When there is a significant change of weather, which could mean that conditions are either deteriorating or improving
AUTO identifies a METAR as _____
An automated report, no human intervention/augmentation
The wind on a METAR is referenced to _____ north
True north
How is 30005MPS read on a METAR?
Wind three zero zero at five meters per second
Decode M1/4 SM visibility
Visibility less than 1/4 statute mile
Decode 9999 visibility
Visibility greater than 10 KM
Decode the following R04/P6000FT
Runway zero four visual range more than 6,000 FT
Decode the following R02C/0800U
Runway zero two center visual range 800 meters trending up
FG is used to indicate fog restricing visibility to less than _____.
5/8 SM (can also be seen/written as 1/2SM)
BR is used to indicate mist restricting visibility from _____ to _____ and is never coded with a descriptor.
5/8 SM to 6 SM
Decode VV000
Vertical visibility less than one hundred feet
Define ceiling
- Height above Earth’s surface where the lowest cloud base or obscuring phenomena aloft is classified as broken or overcast.
- Vertical visibility into a surface-based total obscuration
Phenomena within _____ SM of the station will be reported as at the station.
5 SM
Phenomena beyond _____ will be reported as distant, _____.
10 SM, DSNT
Decode the following: Tornado B13 DSNT NE
Tornado began 13 min past the hour to the distant northeast
Decode the following:
PK WND 28045/1955
Peak wind, 280º at 45 knots, occurred at 1955Z
Define wind shift
A change in wind direction of 45º or more in less than 15 minutes with sustained winds of 10 KTS or more
What is IMC?
Instrument Meteorological Conditions
Ceiling < 1000’ and/or Visibility < 3 SM
What is the difference between FG and BR?
Mist restricts visibility to between 1/2 and 6 SM, Fog restricts visibility to less than 1/2 SM
What contractions are used for the frequency of lightning?
OCNL - occasional, FRQ - frequent, CONS - continuous