meteorology exam 2
An air mass is a large body of air, usually 1600
kilometers (1000 miles) or more across, that is
Define air mass
characterized by similar temperature and
moisture conditions at any given height.
A region under the influence of an air mass
usually exhibits relatively uniform weather
air-mass weather.
conditions perhaps for several days, a situation
referred to as air-mass weather.
location where an air mass forms; must be a
source region
relatively large and uniform area
A cold air mass that forms in a high-latitude
Polar (P) Air Mass
source region.
originates over Arctic Circle in NW Canada, parts
of Alaska, very dry bitterly cold, only arrives in
Arctic air mass (A or cA)
Austin 1 or 2 times a year- get temps in the
teens
A warm-to-hot air mass that forms in the
tropical (T) air mass
subtropics.
An air mass that originates over the ocean.
maritime (m) air mass
These air masses are relatively humid.
an air mass that forms over land; it is normally
continental (c) air mass
relatively dry
List the basic criteria for an air-mass source Areas in which air masses originate, called
region and identify the source regions that source regions, must be extensive and physically
influence North America. uniform and must be characterized by a general
stagnation of atmospheric circulation.
The classification of an air mass depends on the
latitude of the source region and the nature of
the surface in the area of origin—ocean or
continent. Air masses are identified by two-letter
codes. Continental (c) designates an air mass of
land origin, with the air likely to be dry, whereas
a maritime (m) air mass originates over water
and therefore is humid. Polar (P) and arctic (A)
air masses originate in high latitudes and are
, cold. Tropical (T) air masses form in low latitudes
and are warm.
According to this classification scheme, the basic
types of air masses are continental polar (cP),
continental arctic (cA), continental tropical (cT),
maritime polar (mP), and maritime tropical (mT).
A nor'easter (also northeaster; see below) is a
macro-scale extratropical cyclone in the western
North Atlantic Ocean. The name derives from
the direction of the winds that blow from the
nor'easter
northeast. The original use of the term in North
America is associated with storms that impact
the upper north Atlantic coast of the United
States and the Atlantic Provinces of Canada.
Isohyet MAP OF LINES OF EQUAL RAINFALL
(aka Pineapple express)—a narrow band of
intense atmospheric moisture that travels from
the tropical Pacific thousands of miles to slam
atmospheric rivers into the west coast of North America. They can
carry 10-15x more water than the Mississippi,
and deliver intense storms (rain and snow) to
California.
Continental polar (cP) and maritime tropical
(mT) air masses primarily influence the weather
of North America, especially east of the Rocky
Mountains, because the convergence associated
with traveling cyclones draws these contrasting
air masses together.
Maritime polar (mP) air masses that influence
the Pacific coast of North America tend to be
unstable in winter and stable in summer. Storms
called nor'easters result when mP air from the
Summarize the weather conditions associated North Atlantic is drawn into a low-pressure
with the air masses that influence North America center along the east coast.
during the summer and winter. Maritime tropical (mT) air masses from the Gulf
of Mexico and adjacent Atlantic Ocean are a
major source of precipitation in the eastern two-
thirds of the United States.
Pacific mT air masses affect North America much
less than mT air masses from the Gulf of Mexico
and the adjacent North Atlantic. Sometimes mT
air from the subtropical Pacific is part of an
atmospheric river, a narrow corridor of
concentrated moisture that can produce heavy
rains along the Pacific coast.
An air mass is a large body of air, usually 1600
kilometers (1000 miles) or more across, that is
Define air mass
characterized by similar temperature and
moisture conditions at any given height.
A region under the influence of an air mass
usually exhibits relatively uniform weather
air-mass weather.
conditions perhaps for several days, a situation
referred to as air-mass weather.
location where an air mass forms; must be a
source region
relatively large and uniform area
A cold air mass that forms in a high-latitude
Polar (P) Air Mass
source region.
originates over Arctic Circle in NW Canada, parts
of Alaska, very dry bitterly cold, only arrives in
Arctic air mass (A or cA)
Austin 1 or 2 times a year- get temps in the
teens
A warm-to-hot air mass that forms in the
tropical (T) air mass
subtropics.
An air mass that originates over the ocean.
maritime (m) air mass
These air masses are relatively humid.
an air mass that forms over land; it is normally
continental (c) air mass
relatively dry
List the basic criteria for an air-mass source Areas in which air masses originate, called
region and identify the source regions that source regions, must be extensive and physically
influence North America. uniform and must be characterized by a general
stagnation of atmospheric circulation.
The classification of an air mass depends on the
latitude of the source region and the nature of
the surface in the area of origin—ocean or
continent. Air masses are identified by two-letter
codes. Continental (c) designates an air mass of
land origin, with the air likely to be dry, whereas
a maritime (m) air mass originates over water
and therefore is humid. Polar (P) and arctic (A)
air masses originate in high latitudes and are
, cold. Tropical (T) air masses form in low latitudes
and are warm.
According to this classification scheme, the basic
types of air masses are continental polar (cP),
continental arctic (cA), continental tropical (cT),
maritime polar (mP), and maritime tropical (mT).
A nor'easter (also northeaster; see below) is a
macro-scale extratropical cyclone in the western
North Atlantic Ocean. The name derives from
the direction of the winds that blow from the
nor'easter
northeast. The original use of the term in North
America is associated with storms that impact
the upper north Atlantic coast of the United
States and the Atlantic Provinces of Canada.
Isohyet MAP OF LINES OF EQUAL RAINFALL
(aka Pineapple express)—a narrow band of
intense atmospheric moisture that travels from
the tropical Pacific thousands of miles to slam
atmospheric rivers into the west coast of North America. They can
carry 10-15x more water than the Mississippi,
and deliver intense storms (rain and snow) to
California.
Continental polar (cP) and maritime tropical
(mT) air masses primarily influence the weather
of North America, especially east of the Rocky
Mountains, because the convergence associated
with traveling cyclones draws these contrasting
air masses together.
Maritime polar (mP) air masses that influence
the Pacific coast of North America tend to be
unstable in winter and stable in summer. Storms
called nor'easters result when mP air from the
Summarize the weather conditions associated North Atlantic is drawn into a low-pressure
with the air masses that influence North America center along the east coast.
during the summer and winter. Maritime tropical (mT) air masses from the Gulf
of Mexico and adjacent Atlantic Ocean are a
major source of precipitation in the eastern two-
thirds of the United States.
Pacific mT air masses affect North America much
less than mT air masses from the Gulf of Mexico
and the adjacent North Atlantic. Sometimes mT
air from the subtropical Pacific is part of an
atmospheric river, a narrow corridor of
concentrated moisture that can produce heavy
rains along the Pacific coast.
