Air Masses and Fronts Flashcards
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What are the 4 types of air masses?
Tropical Air Mass - Warm
Polar Air Mass - Cold
Maritime Air Mass - Moist
Contential Air Mass - Warm
Which of these air masses does NZ usually experience?
Tropical Maritime Air Mass
Polar Maritime Air Mass
Tropical Contential Air Mass
Polar Contential Air Mass
Tropical Maritime Air Mass
Polar Maritime Air Mass
What conditions occur when a Polar Air Mass hits NZ Land?
Moves across warm land, therefore the ELR rate creates instablitiy.
Turbulence
Icing
Thunderstorms
Snow
Visibiltiy is good.
What happens if an air mass hits cooler land?
ELR creates more stable air as the lower levels are cooler.
Results in Stratus Clouds.
What are the 4 types of front?
Cold
Warm
Occuleded
Stationary
What happens when 2 air masses meet?
Colder air is always at the bottom
Creates a frontal Zone
Angle depends on the stability of the air.
Symbol and weather for a cold front?
Cold air is moving and pushing under warm air. Resulting instablity
Pointed spikes
Unsettled weather
Cumulus and thunder clouds
Extreme temp changes
Sudden and sevre weather
Symbol and weather for warm front?
Semi circles on outside of front ( direction of Travel )
Weather is usually settled
Some clouds forming as the warm air moves under the cold air
Wide area
Symbol and weather for occluded front?
Mix of spikes and semi circles
Mix of weather conditions for cold and warm fronts
Symbol and Weather for stationary front?
Semi circles and spikes on opposite sides of the line.
Means that one air mass is not stronger than the other.
How do cold and warm fronts usually move?
Together. The sector between is called the warm sector.
What would you experience with a warm front in flight ( flying toward it)?
Weather deteroriates
Ceiling lowers
Visibility gets worse
Pressure falls
Temp Rises
Wind veers to parallel at surface level
Wind speed increases
What type of clouds form with a warm front?
THe slope is gentle, so the air rises.
Forming
- SC
- NimboStratus
- Altostratus (AS )
- CirroStratus (Cs )
- Cirrus ( CI )
Below the line:
- Stratus
- SC
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Once behind a warm front - what weather can we expect?
Cloud and visibility as normal.
A warm front can bring a risk of freezing, why?
When flying toward the front the freezing level is low - at the front it rises.
This can lead to freezing rain.
As you fly toward a cold front, what can you expect?
No specific weather
Unsable weather
Cumulus clouds
Wind veers to parallel
Fall in pressure
Wind speed increases
Gusty winds
Squalls
Severe turbulence
Hail or rain
For VFR we should always divert instead of flying through a cold front.
After a cold front what weather can we expect?
Pressure rises
Temp/dew point drop
Unstable air
Showers and secondary frton
Visibility is good between showers
For VFR we should always divert instead of flying through a cold front.
How does an occluded front form?
Cold and Warm fronts are usually travelling together ( with a warm sector )
If the cold front overtakes the warm front.
Unsettled weather breifly and then an occluded front
No specifc weather.
Which direction does a stationary front face ( relative to isobars)?
What is the expected weather ( clouds and winds )
Parallel to the isobars.
Wind flow is parallel.
Not a lot of wind or clouds form.
How do the isobars near a front dictate the weather?
V shaped sharp isobars indicate an active front, due the pressure gradient.
A cold front passing over a mountainous region can result in an increase in temp… why?
THe cold air falls into valley,
The cold front results in cold air falling… but it’s warmer than the air on the ground.
