Maritime Tropical - Tropical and subtropical oceans. [ Warm, moist, of variable stability ]
Equatorial - Oceans near the equator. [ Warm, very moist, unstable ]
Develops between air masses.
forms where an advancing cold air mass meets warmer air.
forms where an advancing warm air mass meets colder air.
Common boundary when neither air mass displaces the other.
formed when a cold front overtakes a warm front.
Characteristics of Atmospheric Disturbances
Extremely variable in size, migratory and transient, brief duration, and relatively predictable in weather conditions.
Mid Latitude Disturbances
Principal battleground of tropospheric phenomena: where polar and tropical air masses meet, where most fronts occur, and where weather is most dynamic and changeable from season to season and from day to day.
same weather day after day, week after week and month after month. Almost the only breaks are provided by transient atmospheric disturbances. Mostly tropical cyclones - known as hurricanes.
Localized Severe Weather
Other parts of the globe. Short-lived. Mostly thunderstorms and tornadoes.
Mid latitude cyclones
Probably most significant of all atmospheric disturbances. Typically has a diameter of 1600 km. Counterclockwise converging circulation. Attracts cool air from the north and warm air from the south.
Mid latitude Anticyclones
Major disturbance in the general flow of the westerlies. Referred to as a 'HIGH' (H). Typically larger than a mid latitude cyclone and generally moves west to east. Clockwise in Northern Hemisphere and counterclockwise in Southern Hemisphere.
Long but weak migratory, low pressure system that may occur almost anywhere between 5 and 30 degrees latitude.
Intense, low pressure disturbances that develop in the tropics and occasionally move poleward into the mid latitudes.
Has wind speeds less than 33 knots (61 km or 38 mph) but has developed a closed wind circulation pattern.
Has winds between 34 and 63 knots (63-117 km or 39-73 mph).
Has winds greater than 64 knots (119 km or 74 mph).
Refer to significant change in wind direction or wind speed with increasing elevation.
the least likely zone of formation for a large air mass
Tornadoes, although erratic in their pathways, are always characterized by ________ pressure.
Has the highest incidence of tornadoes
The "eye" of the hurricane is a zone characterized by ________.
Southwest to northeast
The average directional movement of tornadoes is ________.
East to west
The average directional movement of hurricanes is ________.
The correct designation for a hurricane is as a/an ________.
Accompany hurricanes, tornadoes, extratropical cyclones and cold fronts.
As a rule, thunderstorms are unknown poleward of ________ latitude.
North America's greatest hurricane disaster took place at ________.
Mid latitude anticyclone
Calm, fair weather is most likely to result from a/an ________.
Of the list below, the coldest air is bound to be associated with a/an ________ air mass.
Which of the following best represents the length of the life cycle of a typical midlatitude cyclone?
normal slope for a cold front
The most active phase of a thunderstorm is called the ________ phase.
Properties of an air mass
Large, relatively uniform, travel as recognizable entity, must modify as it leaves its source region.
When neither air mass displaces the adjacent one, their boundary is called a(n) ________ front.
The average hurricane exists, on the average, for about ________.
A tornado advances at a rate of speed of ________ kilometers per hour.
The slope of a warm front generally averages about ________.
On the average, ________ fronts move the fastest of all fronts.
Extratropical cyclones and anticyclones function as migratory perturbations in the ________.
Hurricane formation is very rare within ________ degrees of the Equator.
Thunderstorms are violent ________ storms accompanied by thunder and lightning.
Stable anticyclones act as a ________ to moving cyclones.
a few hundred
An easterly wave is on the order of ________ kilometers long.
A distinguishing feature of thunderstorms.
On a weather map, a symbol consisting of triangles arranged along one side of a line indicates a(n) ________ front.
The global westerly wind zone most heavily impacts the ________ latitudes.
The month most likely for a hurricane to occur in the Northern Hemisphere is ________.
Which country is the most likely place on Earth for a tornado to occur?
An average air mass is on the order of ________ kilometers in diameter.
A wave cyclone
A midlatitude cyclone is also properly termed ________.
Upper air divergence is most closely associated with surface ________.
above the ground
In an occluded front, the warm air sector is ________.
The movement of middle latitude cyclones is determined by the jet stream and ________.