Characterizing and air mass:
Air masses may extend 1600 km or more across Air masses are usually several km thick Air masses are characterized by similar moisture content at any given level. Air masses generally have similar temperatures at any given level.
Which parameters characterize an air mass that develops over an equatorial ocean?
Humid and warm
The classification of air mass types is based on which parameter?
Which type of air mass is responsible for depositing large quantities of lake-effect snow during the winter
Continental polar air mass
a maritime tropical air mass is headed toward the city. What type of weather would you expect to arrive over the next few days? In Houston TX
warmer and wetter than usual
What is a front?
the boundary between two air masses of different temperatures
Where does rain occur in a warm front?
Rain occurs along and in front of a warm front.
Rain occurs along and behind a cold front.
Rain occurs along and behind a cold front.
How are rain patterns different near warm and cold fronts?
Rain near a cold front occurs over a smaller spatial area and is more intense than near a warm front.
What determines whether a front is called a cold front or a warm front?
The type of front is determined by which air mass is moving.
Why does rain occur near a cold front?
Rising warm air cools, resulting in cloud formation and rain.
Why does rain occur near a warm front?
Rising warm air cools, resulting in cloud formation and rain
When the ground position of a front moves so that warm air occupies territory that was previously held by cold air, what type of front is it?
When cool air rapidly displaces the warmer air along a cold front, which cloud type is produced?
The advance of which type of air mass produces most cold fronts that develop in the United States?
continental polar air mass
What is the result when a warm front is squeezed upward between two cold fronts, producing complex precipitation patterns?
The result is an occluded front
As a cold front moves into a region, which weather pattern is likely to result?
severe thunderstorms, high winds, heavy rains, and hail
What happens when warm air collides with a cold front?
Warm air moves up and over a cold air mass. Warm air forms cumulonimbus clouds and produces thunderstorms.
Which types of air masses must interact for a low-pressure system to develop in the middle latitudes of North America?
maritime tropical and continental polar
As a warm front in a middle-latitude cyclone moves toward a region, what weather conditions would you expect to be the result?
falling pressure and rising temperature
As a middle-latitude cyclone pushes a cold front through a region, what type of weather pattern would you expect?
thunderstorms and cumulonimbus clouds
Which type of clouds most often develops with the passing of a warm front over a region and is associated with a prolonged period of precipitation?
As a cold front associated with a middle-latitude cyclone passes over a region, which type of precipitation pattern may result?
heavy rain that passes quickly
Which atmospheric feature drives middle-latitude cyclones that produce cold and warm fronts and changing weather patterns?
In which season do middle-latitude cyclones typically generate the most severe weather in North America?
Typically, in which direction do middle-latitude cyclones move when crossing the North American continent?
west to east
Middle-latitude cyclones typically have both warm and cold fronts associated with them. If the cold front is traveling faster than the warm front in the cyclone, which weather phenomenon can result?
an occluded front
In North America, which two types of air masses interact to create middle-latitude cyclones?
continental polar and maritime tropical
What are midlatitude cyclones?
migrating low-pressure cells that move in the band of the westerlies
What happens when air masses of different temperatures meet?
Well-defined boundaries form between the air masses.
Which of the following statements about movement in midlatitude cyclones are accurate?
Surface winds move counterclockwise The cold front advances faster than the center of the storm, and the warm front advances more slowly than the center. The entire cyclone moves from west to east.
What is occlusion in a midlatitude cyclone?
Occlusion is the process by which a cold front overtakes a warm front.
When do midlatitude cyclones stop producing storms?
when the cold front has completely taken over the warm front
What are the three stages of thunderstorm development?
cumulus, mature, and dissipating
What is a tropical cyclone?
a low-pressure disturbance that develops over warm, tropical waters
Where are tropical cyclones found?
lower and middle latitudes
Which of the following names mean "tropical cyclone"?
cyclone, typhoon, hurricane
Why is heavy rain associated with hurricane formation?
Rising, moist air cools. As air cools, water condenses and eventually falls.
Why is warm, moist air considered the "fuel" for a hurricane?
Air warms as it rises. As air warms, liquid water will evaporate out as water vapor. Evaporation releases heat, providing energy to the hurricane.
How big can the diameter of a hurricane become?
What other natural hazards are associated with tornado formation?
Why does air spiral parallel to Earth's surface during initial stages of tornado formation?
Because of friction, surface winds move more slowly than winds higher in the air column.
What can cause the horizontally rotating air spiral to become the vertical spiral of a tornado?
Updrafts associated with thunderstorm clouds can tilt the horizontal column of spinning air.
How are mesocyclones and tornadoes related?
Mesocyclones can turn into funnel clouds. A funnel cloud that touches the ground is called a tornado.
What has steepest pressure gradient?
Tornadoes most often move TOWARDS what direction?
A cT air mass is ________.
warm and dry
An mP air mass is ________.
cold and humid
On a weather map, ________ fronts are shown by a line with triangular points on one side.
On a weather map, ________ fronts are shown by a line with semicircles extending from one side.
When an active cold front overtakes a warm front ________.
an occluded front forms
The electrical discharge of lightning rapidly heats the air, which in turn causes it to expand explosively to produce ________.
Typhoon is another name for a ________.
When conditions appear favorable for tornado formation, a(n) ________ is issued for areas covering about 65,000 square kilometers.
What is an air mass?
a large body of air with similar temperature and moisture at any given altitude a large body of air usually 1600 kilometers or more across
When an area is experiencing several consecutive days of rather constant weather, it is probably ________.
Cold fronts and warm fronts in the middle latitudes are often associated with a ________.
The precipitation associated with a warm front typically arrives ________ the actual frontal boundary.
considerably ahead of
An occluded front is depicted on a weather map as a line with semicircles on one side and triangular points on the other side.