weather theory Flashcards
(31 cards)
why should you avoid thunderstorm anvil tops?
there could be turbulence or hail below
what are the stage of a thunderstorm
cumulus (updrafts)
mature (updrafts & downdrafts)
dissipating (downdrafts)
what is a microburst?
what are the characteristics of a microburst?
- 6000 fpm
lasts 15 min
1.5 miles (radius or diameter?)
what are the three types of structural icing and which is the most dangerous?
rime, clear, mixed
clear is the most dangerous… it is the heaviest and accumulates the most rapidly
what stage of a thunderstorm is the most dangerous , why, which was to fly to avoid?
the mature stage is the most dangerous
fly at least 20 nm away
fly away from it… opposite direction that the anvil top is pointing
what does GRB50 mean on a METAR?
large/moderate (?) hail beginning 50 minutes past the hour
what does COR mean on a METAR?
correction to a previously issued METAR
tell me about a thunderstorm
the sources, the stages, and what the stages entail
what is virga?
rain that evaporates before it reaches the ground
what are the 3 types of fog?
advection:
radiation:
upslope:
how powerful can a microburst be in fpm?
> 6000 fpm
how does a microburst affect airplane performance?
depending on the aircraft’s direction it can either severely effect airspeed and lift. the microburst is like a upside down mushroom. air swirls out from the center
what does TSRA mean on a METAR?
moderate rain and thunderstorms
what type of clouds determine a ceiling on a METAR?
BKN, OVC, vertical visibility
can you draw a microburst and explain whats happening?
a microburst is an area of concentrated downdrafts which can be as strong as 6000 fpm. It usually last no more than 15 minutes
what is needed for the creation of a thunderstorm?
source of moisture, unstable atmosphere or temperature lapse rate, and a lifting mechanism (convective, orographic, or frontal)
how can you tell which way a thunderstorm cell is moving?
it is moving in the direction the anvil at the top is pointing
can you describe one type of fog and how it is formed?
advection:
radiation fog: develops on clear cool nights with light or no wind
upslope:
what does LTGICCC mean in a METAR?
lightning, in cloud, cloud to cloud
lightning that is traveling from one cloud to another…?
what does TSE50 mean on a METAR?
thunderstorms ended 50 minutes past the hour
what kind of weather would you encounter with a high and low pressure system?
high pressure: dry and sunny
low pressure: clouds and rain
why is 20nm the recommended distance to avoid a thunderstorm?
hail and severe turbulence can occur within 20NM of a thunderstorm
what does OHD mean on a METAR?
overhead
