Final New Section

Question 1

Cold core system

Answer 1

Cold- core anticyclone- actually a dome of continental polar or Arctic air and, depending on the specific type of air mass is labeled either a polar or Arctic high. Products of extreme radiational cooling over the often snow-covered continental interior of North America well north of the polar front.
SHALLOW SYSTEMS- clockwise circulation weakens with altitude and frequently reverses direction aloft.. Hence a cold trough overlies a cold anticyclone.

They exert the highest surface pressures in winter, when is colder and more dense

Question 2

What/where is the ITCZ

Answer 2

Intertropical convergence zone

Stimulates thunderstorm activity and its north-south seasonal shifts are responsible for the seasonal variations in precipitation in portions of the tropics

FOLLOWS THE SUN, moving northward in the northern hemisphere spring and southward in the northern hemisphere autumn. The rainy season is summer (high sun) and the dry season is winter (low sun).

Question 3

What is a front?

Answer 3

A narrow zone of transition between air masses of contrasting air density, that is different temperature, humidity or both. Fronts are classified as stationary, warm or occluded

Question 4

know meridional/zonal flows and what they mean

Answer 4

Zonal flow pattern- the westerlies blow almost directly from west to east nearly parallel to latitude lines, with only w weak meridional component. The north-south exchange of air masses is minimal. Cold air masses stay north and warm air masses remain south.

Meridional flow pattern- the westerlies exhibit considerable amplitude and flow in a pattern of deep troughs and sharp ridges. Masses of cold air surge southward and warm air streams northward. Greater west to east temperature contrasts develop over the United States and southern Canada. Where contrasting air masses collide, warm air overrides cold air, and the stage is set for the development of extra tropical cyclones that are then steered by the westerlies.

Question 5

understand the polar jet and it’s seasonal variations (meridional vs. zonal)

Answer 5

Produces strong vertical wind shear that maintains a vigorous updraft and favors great vertical development of thunderstorm cells. The jet contributes to a stratification of air that increases the potential instability of the troposphere.
It causes dry air to subside over a surface layer of maritime tropical air. This produces a layering of air that sets the stage for explosive convection and development of severe thunderstorm cells

Question 6

what is a jet streak/it’s quadrants/ divergence and convergence associated with a jet streak

Answer 6

An area of accelerated air flow within a jet stream; the wind may strengthen by as much s an additional 100km per hr. They occur where surface horizontal temperature gradients are particularly steep and play an important role in the generation and maintenance of synoptic-scale Cyclones. The strongest jet streaks develop during winter in the polar front jet stream along the east coasts of North America and Asia.

Play an important role in the generation and maintenance of extra tropical cyclones. Air flowing through a jet streak changes speed and direction.. These changes induce a pattern of horizontal divergence and horizontal converfence.

4 quadrants- left-rear, right- rear, left- front, and right- front,
Horizontal divergence occurs in both the left- front and right-rear quadrants and horizontal convergence takes place in both the right- front and the left-rear,

Provides upper air support for a cyclone by contributing horizontal divergence aloft.

Strongest horizontal divergence occurs in the left-front quadrant- so it’s under this sector of the jet streak that a cyclone typically has the best chance of developing.

Question 7

what is upwelling

Answer 7

Ekman transport moves surface waters away from the coast, those waters are replaced by water that wells up from below in a process.

Responsible for the tongue of relatively cool surface waters along the equator in the eastern tropical pacific. Near the equator the northeast trade winds of the northern hemisphere converge with the southeast trade winds of Southern Hemisphere.

Answer 8

Maritime- very warm and humid, source regions are tropical and subtropical seas. Keeps properties year round and is responsible for oppressive summer heat and humidity east of the Rocky.

Continental- winter air is cold. Source is ground and is usually snow covered. Short daylight. Solar radiation is weak. Radiational cooling is extreme.

Question 9

know the clouds progression as a warm front approaches

Answer 9

Cirrus-cirrostratus- altostratus- nimbostratus- and stratus

Question 10

signs of warm air advection (clouds)/where is typically occurs (which side of a ridge vs trough)

Answer 10

1. High cirrus clouds in the western sky.

Behind (west of a ridge)

Question 11

know how frontal precipitation sets up

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Answer 11

When air cools sufficiently.

Question 12

differential heating of land vs water

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Answer 12

Lake breeze- a relatively cool surface wind directed from a large lake toward land in response to differential heating between land and water daylight

Sea breeze-

Cool wind directed from water onto land

Question 13

what/where is a Chinook wind

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Answer 13

Air that is adiabatically compressed as it is drawn down the leeward side of a mountain range. As a consequence the air is warm and dry causing rapid temperature rises and reduction in snow cover

Strong and gusty

Rocky Mountains

Answer 14

Towering cumulus stage.- cumulus clouds form verity calmly and laterally. Surge. Forced convection
UPDRAFT- saturated air streams upward. Keeps water suspended

Mature stage- precipitation reaches the surface.
DOWNDRAFT- the precip pulls the air down.
The downdraft air resembles a cold front and is called a gust front

Dissipating stage- subsiding air replaces the updraft throughout the cloud effectively cutting off the supply of moisture delivered by the updraft. The air warms the humidity decreases precip ends no clouds vaporize

Question 15

higher tops mean

Answer 15

more severe thunderstorms

The greater the altitude of the top the more severe the storm.

Magnitude of the vertical wind shear

Question 16

what is a squall line … where it forms

Answer 16

An elongated cluster of thunderstorm cells that is accompanied by a continuous gust front at the lines leading edge. It is most likely to develop in the warm southeast sector of a mature extra tropical cyclone ahead of and parallel to the cold front.

Their cells are usually more intense.

As it surges forward warm humid air is lifted and forced into the updraft located at the leading edge of the squall line.

Dry line

Question 17

what is a mesoscale convective complex

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Answer 17

Is nearly circular cluster of many interacting thunderstorm cells covering an area that may be a thousand times larger than that of a single isolated thunderstorm cell. It can cover an area equal to that of the state of Iowa.

Warm season- march through September.

Not front associated.

Upper level ridge of high pressure.

Question 18

what type of weather can a severe thunderstorm produce

Answer 18

Flash floods or tornados.

Strong winds and hailstones

Question 19

Where in the U.S. are thunderstorms most common

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Answer 19

Central Florida

North to South increase

Great Plains

Question 20

what makes thunder

Answer 20

Is a sharp clap or rumbling sound after lightening.

Lightening heats the narrow conducting path to high temps. The rapid rise in temps is accompanied by a tremendous increase in air pressure locally that generates a shock wave. The shock wave propagates outward producing sound waves that are heard as thunder. The first thunder clap we bear is generated by the nearest part of the lightening flash. Subsequent sound waves reach us from portions of the flash that are progressively further away. Hence the rumble

Question 21

how do tornadoes rotate

Answer 21

Move in circles and even to describe as figure 8s.

Northern hemisphere tornados rotate counterclockwise direction. Only 5% rotate clockwise. Counterclockwise comes from the parent thunderstorm.

The changing direction of the inward directed pressure gradient force produces the centripetal force that maintains the rotation of the air column.
They track from southwest to northeast but any direction is possible.

Question 22

what is a funnel cloud

Answer 22

Localized lowering of a cloud base into tapering rotating column composed of tiny water droplets. If it remains aloft it is a funnel cloud if it touches ground it is a tornado.

Question 23

how to protect yourself from a tornado

Answer 23

Get to the lowest surface

Question 24

where is tornado alley

Answer 24

A north- south corridor stretching from eastern test and the Texas panhandle northward through Oklahoma, Kansas, Nebraska, and into South Dakota.

Kansas and Oklahoma have the highest annual incidence of tornados per unit, whereas local tornado frequency maxima occur from central Iowa eastward into central Indiana and along the gulf coast.

Question 25

what is a dry line

Answer 25

A boundary between continental tropical air and maritime tropical air in the southeast sector of a mature extra tropical cyclone likely site for the squall line and severe thunderstorm development

Advanced eastward during the day and retreats westward at night.

Brings uplift similar to cold front

Question 26

peak months for tornadoes

Answer 26

May and June when atmospheric conditions are optimal for deep convection and the severe thunderstorms that spawn tornados

Question 27

What is most destructive about a hurricane

Answer 27

Heavy rains and inland flooding, strong winds, tornadoes and storm surge.

FLOODING

Question 28

where are the strongest winds in a hurricane

Answer 28

Eye wall

Question 29

general characteristics about a hurricane

Answer 29

Intense cyclone

Summer or early fall when sea- surface temps are highest.

Maximum sustained wind speed of at least 119 km per hr (74 mph).

Develops on a uniformly warm and humid air mass. No associated fronts or frontal weather.

EYE- area of cloudless skies subsiding air and light winds. Shrinks in diameter as the Hurricanes strengthen.

Eye wall- the ring of the thunderstorm. STRONGEST

Question 30

it is usual for tornadoes to accompany a hurricane

Answer 30

It can happen.. But not typical. It happens after the hurricane enters the westerly steering current and curves toward the north northeast

Question 31

understand latitudinal winds .. ie.. trade winds, horse latitudes

Answer 31

horse latitudes- areas of high persistent light winds or calm air between about 30-35 degrees N and S under subtropical anticyclones. Region of calm air.

Trade winds- surface winds blown from the northeast out of southern flanks of the anticyclones. The most persistent winds on the planet in some regions blowing from the same direction 80% of the time.

Question 32

Warm core cyclone

Answer 32

Forms south of the polar front and consists of extensive areas of subsiding warm, dry air. Strengthen with altitude. Massive systems with a circulation extending from Earth’s surface up to the tropical troposphere.
Subtropical May stretch across North America other warm core anticyclones may develop over the interior of North America. In summer.

Vertical structure and the density contrast between warm and cold core.

The total mass of air over the center of a warm-core anticyclone related to a higher tropopause, compared to the surrounded atmosphere is responsible for the warm anticyclones high surface pressure.

Question 33

that a cold front moves

Answer 33

faster than a warm front