AVIATION METEOROLOGY FOR GROUND
STAFF
P2 Explain how significant weather features
affect the UK as a result of air masses and local
influences.
The significant weather features that affect the UK are:
• Unstable air
To be unstable the lowest layers of an air mass must be so warm
and/or humid that, if some of the air rises, then that air parcel is
warmer than its environment, and so it continues to rise. This
, condensation releases heat, which
warms the air parcel, which can cause
the parcel to rise higher still. Unstable
air means that, with very little warning,
the weather can change rapidly. If we
compare the temperature of this air to
the temperature of the air just above,
we can determine if it is solid or
unstable (likely to remain in place) or
unstable (likely to move). Orographic lifting will occur in the Rocky
Mountains on the east side of the range when the wind is from the
east. Frontal uplift occurs when two different air masses interact.
Cold fronts force warm air up where it cools, forming clouds and
precipitation. Warm fronts climb up the backside of cooler masses of
air. The rising warm air cools to produce clouds and precipitation.
Higher temperatures are worsening many types of disasters,
including storms, heat waves, floods, and droughts. A warmer
climate creates an atmosphere that can collect, retain, and drop
more water, changing weather patterns in such a way that wet
areas become wetter and dry areas drier. The result is poor visibility
for people on the ground and, especially, people flying in aircraft.
Unstable air masses may not have this poor visibility because the air
mass is constantly blowing around and disturbing the particles that,
if settled, would create haze, and reduce visibility. Effects of
atmospheric instability in moist atmospheres include thunderstorm
development, which over warm oceans can lead to tropical
cyclogenesis, and turbulence. Stable atmospheres can be associated
with drizzle, fog, increased air pollution, a lack of turbulence, and
undular bore formation. Because of convection, all cumulus clouds
form. In order to create the cloud, it cools and water vapor
condenses as air hot at the surface is lifted. This will rise in height
and size during the day, if conditions permit, and can gradually form
into clouds of cumulonimbus. Often, cumulus indicates good
weather, sometimes showing up on bright sunny days as they are
detached, individual, cauliflower-shaped clouds usually spotted in
fair weather conditions. Thunderstorms develop when the
atmosphere is unstable. This is when warm air exists underneath
much colder air. As the warm air rises it cools and condenses
forming small droplets of water. The gust of warm air is swift if there
is sufficient turbulence in the air, and the water vapor can easily
STAFF
P2 Explain how significant weather features
affect the UK as a result of air masses and local
influences.
The significant weather features that affect the UK are:
• Unstable air
To be unstable the lowest layers of an air mass must be so warm
and/or humid that, if some of the air rises, then that air parcel is
warmer than its environment, and so it continues to rise. This
, condensation releases heat, which
warms the air parcel, which can cause
the parcel to rise higher still. Unstable
air means that, with very little warning,
the weather can change rapidly. If we
compare the temperature of this air to
the temperature of the air just above,
we can determine if it is solid or
unstable (likely to remain in place) or
unstable (likely to move). Orographic lifting will occur in the Rocky
Mountains on the east side of the range when the wind is from the
east. Frontal uplift occurs when two different air masses interact.
Cold fronts force warm air up where it cools, forming clouds and
precipitation. Warm fronts climb up the backside of cooler masses of
air. The rising warm air cools to produce clouds and precipitation.
Higher temperatures are worsening many types of disasters,
including storms, heat waves, floods, and droughts. A warmer
climate creates an atmosphere that can collect, retain, and drop
more water, changing weather patterns in such a way that wet
areas become wetter and dry areas drier. The result is poor visibility
for people on the ground and, especially, people flying in aircraft.
Unstable air masses may not have this poor visibility because the air
mass is constantly blowing around and disturbing the particles that,
if settled, would create haze, and reduce visibility. Effects of
atmospheric instability in moist atmospheres include thunderstorm
development, which over warm oceans can lead to tropical
cyclogenesis, and turbulence. Stable atmospheres can be associated
with drizzle, fog, increased air pollution, a lack of turbulence, and
undular bore formation. Because of convection, all cumulus clouds
form. In order to create the cloud, it cools and water vapor
condenses as air hot at the surface is lifted. This will rise in height
and size during the day, if conditions permit, and can gradually form
into clouds of cumulonimbus. Often, cumulus indicates good
weather, sometimes showing up on bright sunny days as they are
detached, individual, cauliflower-shaped clouds usually spotted in
fair weather conditions. Thunderstorms develop when the
atmosphere is unstable. This is when warm air exists underneath
much colder air. As the warm air rises it cools and condenses
forming small droplets of water. The gust of warm air is swift if there
is sufficient turbulence in the air, and the water vapor can easily
