Fronts Flashcards
Source regions
regions where generalized air masses form
- have the same repeatable characteristics of moisture and temperature
Where do source regions occur. What are the scales?
High and low latitudes, the mid-latitudes are too variable for them to form
- synoptic scales (100s-1000s km2)
All Air masses have uniform __?
uniform temperature and moisture characteristics
- vary vertically
How do air masses vary vertically
the vertical temperature gradient and moisture relates to the stability of the air mass (stable, unstable, conditionally unstable)
Based on moisture content, air masses can be ?CMTPA
continental (dry)
maritime (moist)
According to their temperature, air masses are ____ based on moisture content
tropical (warm)
polar (cold)
arctic (extremely cold)
cP, cA, mP, cT, mT
cP: continental polar
cA: continental arctic
mP: maritime polar
cT: continental tropical
mT: maritime tropical
cP Air Masses form over _____ land masses?
high latitude
- low temperatures and low moisture
what type of weather in cP air masses
low temperature and moisture
- winter: snow cover (high albedo), short days, low solar angle
- very stable air aloft, no clouds
- tend to migrate south in winter
- masses stay far north in summer due to increased heat energy from the equator moves north
cA air masses are colder or warmer than cP?
colder than cP
cA and cP are separated by the _____?
arctic front
the arctic front is very ___?
shallow, too shallow to produce any uplift needed for precipitation
mP air masses are ______ in temperature and moisture
moderate - they form over water
where do mP air form?
mP air forms over the North Pacific as cP air moves from the interior of Asia
How does cP air change to mP
the warm Sea of Japan converts the cold and dry air
Northeasters
when the center of the counter-clockwise spinning air moves past a costal location, the air masses picks up moisture and delivers it back to the landscape as northeast winds
strong winds combined with added moisture, deliver a storm able to drop a large amount of rain/snow to the region in a short time
where does mP affect?
east coast of North America
- an intense low pressure system moves up the east coast
cT Air Masses form over ____ areas? In which season?
form during the summer over low latitude areas
- very hot and dry and cloud free
- unstable air due to intense heating at the surface, very low dew point
mT Air Masses develop over?
warm tropical waters, causing moist, and unstable air
- ideal for cloud and precipitation formation
- when mT air masses flow over hot land, the air becomes even more unstable, often forming short-term heavy precipitation and thunderstorms
Fronts
the transition zone between two air masses
- refers to the tropical versus polar derived air masses
why dont two air masses mix?
They have different air density characteristics, instead of mixing, one pushes the other
what do fronts affect?
- surface temperature
- also affect windspeed and direction, moisture and precipitation, and uplift and cloud cover.
cold front
occurs when a wedge of cold air advances toward the warm air ahead of it
- warm air will rise above the cold air
which moves more rapidly: warm or cold fronts?
cold fronts move faster which causes the convergence and uplift of the warm air which can lead to cumuliform cloud development and precipitation
