QUESTIONS AND CORRECT ANSWERS
List the characteristic length and time ranges, as well as examples of weather phenomena, for
the following scales of motion: - CORRECT ANSWER Global Scale: Very long time,
can be for weeks; Ex: Tropical Easterlies, POlar Easterlies, Mid-latitude Westerlies
Synoptic Scale: Over large parts of continents; air masses and fronts (high pressures and low
pressures), last for periods of days to as much as a couple of weeks.
Mesoscale: few square kilometers to hundreds of square kilometers for ½ hour up to a large
part of the day; thunderstorm cluster, localized cell storm, supercell thunderstorm in Kansas
Microscale: less than half an hour, can be a few seconds; These can be the simple causes of
rippling in waves or smoke on an unattended frying pan.
Define the term air mass. How do air masses acquire their characteristics? - CORRECT
ANSWER Air mass is a large area with uniform T and moisture characteristics. They
acquire their characteristics by sitting over a source region.
List and describe the 5 main air masses that impact North America. What are the source
regions (origin locations) for each of these 5 air mass - CORRECT ANSWER cP-
These are cold, dry air masses with little cloud cover. They are from high-latitudes of
Northern Canada and Siberia. They are very stable.
cA- very dry, very cold; can come from the Arctic Circle, far north Canada, and the North
Pole.
cT- These are hot, dry air masses that come from desert regions of Mexico. They are unstable.
mP- These are cool, damp air masses that originate over higher latitude oceans, like near
Alaska and near Greenland. They are unstable.
mT- These are warm, humid air masses that originate over the Pacific Ocean west of Mexico,
the Gulf of Mexico, and off the east coast of Florida. They are also unstable.
Define atmospheric pressure. What is the highest atmospheric pressure (adjusted to sea level)
ever recorded on Earth? What is the lowest pressure (adjusted to sea level) ever recorded on
Earth? - CORRECT ANSWER Pressure is the force exerted per unit surface area, and it
is usually used in milibars for meteorology. It can also be seen as inches.
Lowest Pressure: 870 mb 25.69" in eye of Typhoon Tip
, Highest Pressure: 32.01" 1083.8mb
Why are surface pressures adjusted to mean sea level? - CORRECT
ANSWER Pressure increases as altitude increases, so the pressure at a higher altitude
will always be lower and not take into account potential other factors, so adjusting it to sea
level provides a proper basis for comparison.
What is the direction of circulation for High Pressure in the Northern Hemisphere? What is
the direction of circulation for Low Pressure in the Northern Hemisphere? - CORRECT
ANSWER HP = clockwise, LP= counterclockwise
What are the signs that indicate the location or passage of a cold front? Warm Front? -
CORRECT ANSWER Cold front signs= decrease in T, increase in cloud cover,
decrease in dewpoint, change in wind direction, increase in air pressure over a time interval
Warm front- decrease in pressure, increase in T, increase in dewpoint, fog and dreary
nimbostratus clouds.
List the 4 main cyclogenesis locations for mid-latitude cyclones that form & impact the U.S.
east of the Rocky Mountains. - CORRECT ANSWER Southern Alberta (lee side of
Rockies)
Eastern foothills of Rockies near Southern Colorado
Gulf of Mexico
Cape Hatteras
What force determines the speed on the wind? What force determines the direction that wind
will circulate around Highs and Lows? - CORRECT ANSWER Pressure Gradient
Force determines wind speed
Coriolis Force determines the wind direction around lows
Are squall lines (a solid line of thunderstorms) most associated with cold fronts or warm
fronts? Are stratus clouds with continuous light to moderate rain more associated with warm
fronts or cold fronts? - CORRECT ANSWER Squall lines are most associated with
cold fronts.