Meteorology Pt. 2 Flashcards
Clouds
They form when ‘‘moist’’ air is lifted. The moist air is then cooled, and the dew point is reached. At this time, the air is not saturated then changes into a visible state
Clouds
How can the cooling of air be done?
- Lifting
- Moving over a cooler surface
- Cooling from the underlying surface
What does stratus mean?
Layer, sheet like clouds
What are the four basic group of families in clouds
- Low
- Middle
- High
- Clouds with vertical development
What does Cumulus mean?
Heap, puffy clouds
What does Cirrus mean?
Ringlet, wispy clouds
What does Nimbus mean?
Violent Rain, rain clouds
These are layered clouds that form in stable air near the surface due to cooling from below
Stratus
White and puffy that form when stable air is lifted
Stratuscumulus
Gray or black that can be more than several thousands of feet thick, and contain a large amount of moisture
Nimbostratus
Flat, dense clouds that cover a wide area, uniform gray or gray-white in color
Altostratus
Gray or white, patchy clouds of uniform appearance that often form when altostratus starts to break up
Altocumulus
Thin, white, often form in long bands or sheets. The moisture content is low, poses, no icing hazard
Cirrostratus
White, patchy clouds that look like cotton, form as a result of shallow convective currents at high altitude. It may produce light turbulence
Cirrocumulus
Thin and wispy, white or light gray, form in stable air at high altitudes, often in patches or narrow bands in the sky. This can be an advanced warning of approaching bad weather
Cirrus
Form in convective currents from the heating of the earth’s surface, they have flat bottoms and domed shape tops
Cumulus
Looks like large mounds of cotton, white to gray from top to bottom, indicate a deep area of unstable air
Towering cumulus
Commonly called thunderstorms, large, form in very unstable air, gray white to black in color, contain large amounts of moisture
Cumulonimbus
This is technically a low cloud which has its base within so feet of the ground
Fog
What is the term if the fog is less than 20 feet deep?
Ground fog
This forms over low-lying, flat surface on clear, calm, humid nights
Radiation fog
This is a low layer of warm, moist air that moves calm, humid nights
Advection fog
This occurs as cold, dry air moves over comparatively warmer water
Steam fog
This can be defined as any form of particles, whether liquid or solid, that fall from the atmosphere
Precipitation
This is distinguished by very small droplets and is less than 0.02 inches in diameter
Drizzle
This is when the droplets are greater in size by 0.02 inches or greater
Rain
As rain falls, it may freeze as it passes through colder air under the clouds, it then strikes the ground as?
Ice pellets
Water droplets that freeze in the clouds with strong upward currents may grass in size and may fall as?
Hail
This is precipitation composed of ice crystals
Snow
This is a large body of air with fairly uniform temperature and moisture content
Air masses
The area where an air mass acquires the properties of temperature and moisture that determine its stability
Source Region
What is an ideal source region?
A large area with fairly uniform geography and temperature
What are the best areas for air mass development?
Semi-permanent areas of high pressure
What are the temperature characteristics
Polar and tropical
What are the moisture content?
Continental and maritime
This air mass originates over water and contains warm, moist and unstable air. This results in the formation of cumuliform clouds with sharers, turbulence, and good surface visibility
Maritime tropical
This air mass originates near polar areas and contents cold, dry and stable air. This exhibits widespread stratiform clouds, restricted visibility, smooth air , steady rain or drizzle
Continental polar
What happens when an air mass moves over a warm surface?
-the lower surface are heated
-vertical development takes place
-depending on temperature and moisture,this can result in extreme instability
What happens when an air mass flows over cooler surfaces?
-the lower layers are cooled
- vertical development is inhibited
- the stability of the air is then increased
- if the air is cooled to its dew point, it can develop la clouds or fog
This is the boundary between two air masses
Fronts
This is where cold air is moving to displace warmer air
Cold front
When warm air is replacing cold air
Warm front
When a cold front overtakes a warm fronts
Occluded front
When two air masses merge and don’t advance
Stationary front
Pushed along by intense high-pressure systems. Surface friction slows the movement of the front, causing the leading edge of the front to bulge out and steepen the front’s slope
Fast-moving cold front
The leading edge is much shallower compared to a fast-moving front. Produces clouds which extend for beyond the surface front
Slow-moving cold front
When fast moving cold front is colder than the air ahead of the slow - moving front. The cold air replaces the cool air at the surface which forces the warm front aloft (above)
Cold front occlusion
Occurs when the air ahead of the slow-moving warm front is colder than the air within the fast - moving cold front. The cold front rides up over the warm front
Warm front occlusion
They contain strong wind gusts, icing, hail, driving rain, lightning and sometimes tornadoes
Thunderstorms
Violent with wind gusts of 50 or more, hail 3/4 inches in diameter or larger tornado and/or tornadoes
Severe thunderstorm
Usually lasts less than an hour
Single - cell thunderstorm
Severe thunderstorm, may last two hours
Super-cell thunderstorm
A compact cluster of thunderstorms, composed of at mass thunderstorms in different stages of development
Multicell thunderstorm
Scattered thunderstorms which are common during summer afternoons, or in coastal areas at night
Air mass thunderstorm
This often forms 50 - 300 miles ahead of a fast- moving cold front, the most extreme weather conditions, such as destructive winds, heavy hail, and tornadoes
Squall line
Storms which are associated with frontal activity
Frontal thunderstorm
This refers to a lifting action initiates the vertical movement of air. As the air rises and cools to its dew point, water vapor condenses into small water droplets or ice crystals. If sufficient moisture is present, heat released by the condensing vapor provides energy for continued vertical growth of the cloud
Cumulus Stage
The circulation of the thunderstorm cell is organized in this stage. This is the storm’s most violent stage
Mature Stage
The final stage in the cycle wherein updrafts are replaced by downdrafts. The entire thunderstorm starts to weaken
Dissipating Stage
This develops when air currents change direction or velocity rapidly over a short distance. The magnitude of the turbulence depends on the difference between the two air currents
Thunderstorm Turbulence
This is always associated with thunderstorms and can occur in several forms including in-cloud, cloud-to;-cloud, cloud-to-ground and occasionally, between cloud and clear air
Lightning
How large can hail be?
3/4 inches in diameter
These are funnel clouds that reaches the earth’s surface, whether land or sea. Tornadoes exhibit wind speeds exceeding 200 knots.
Tornadoes
A sudden, often violent shift in airflow
Turbulence
State the categories of turbulence
- Low-level turbulence
- Mechanical turbulence
- Frontal turbulence
- Wake turbulence
- Clear air turbulence
This is when obstacles such as buildings or rough terrain interfere with normal wind flow
Mechanical Turbulence
This occurs in the narrow zone just ahead of a fast-moving cold front where updrafts can reach 1,000 feet/min
Frontal Turbulence
When combined with convection and strong winds across the front, these updrafts can produce significant turbulence
Frontal Turbulence
When an airplane generates lift, air spills over the wingtips from the high-pressure areas below the wings to the low-pressure areas above them
Wake Turbulence
This can form when a layer of air slides over the top of another slow-moving air. This is common thought of as high-altitude phenomenon
Clear Air Turbulence
This is a sudden, drastic shift in wind speed and/or direction that may occur at any altitude in a vertical or horizontal plane
Wind Shear
It can subject your aircraft to sudden updrafts, downdrafts, or extreme horizontal wind components, causing a loss of lift or violent changes in vertical speeds or altitude
Wind Shear
This is one of the most dangerous sources of wind shear
Microburst