Mid-Latitude and Tropical Cyclones Lecture Review

Comprehensive vocabulary flashcards covering the characteristics, stages, and phenomena of mid-latitude and tropical cyclones based on the Geography Grade 12 lecture notes.

Mid-Latitude Cyclones

Low pressure weather systems that occur in the middle latitudes between $30^{\circ}$ and $60^{\circ}$ latitude north and south of the equator, also known as temperate cyclones or frontal depressions.

Westerlies

The wind belt associated with the movement and development of mid-latitude cyclones.

Easterlies

The wind belt associated with the movement and development of tropical cyclones.

Initial Stage (Mid-Latitude Cyclone)

The first stage of development where pressure differences between warm tropical air and cold polar air result in a pressure gradient around a polar front, eventually forming a wave.

Mature Stage (Mid-Latitude Cyclone)

The stage where air flows around a low pressure cell, the polar front forms distinct cold and warm fronts, and the area is divided into cold and warm sectors.

Occluded Stage

The stage in a mid-latitude cyclone where the cold front overtakes the warm front, lifting the lighter warm air off the ground.

Cold Front Conditions

Characterized by decreasing temperature and humidity, rising pressure in the cold sector, cumulonimbus cloud cover, and heavy rain or snow.

Warm Front Conditions

Characterized by increasing temperature and humidity, decreasing pressure, nimbostratus clouds, and soft soaking rainfall.

Cold Front Occlusion

A condition where the temperature in front of the system is higher than behind the system, and the cold front cuts into the warm front.

Warm Front Occlusion

A condition where the temperature in front of the system is lower than behind the system, and the warm front cuts into the cold front.

Tropical Cyclones

Intense low pressure storms that develop at the ITCZ outside $5^{\circ}$ north and south of the equator over oceans warmer than $28^{\circ} \text{C}$.

Coriolis Force

The force that causes winds to spiral toward a low pressure center; it is absent at the equator, which is why tropical cyclones do not form between $0^{\circ}$ and $5^{\circ}$ latitude.

Eye of the Cyclone

The clear, calm, and cloudless center of a tropical cyclone where air is warmer due to adiabatic heating and air pressure is at its lowest.

Formative Stage (Tropical Cyclone)

The start of a tropical cyclone characterized by strong updrafts and intensifying low pressure, but without a clear eye yet.

Mature Stage (Tropical Cyclone)

The stage with a well-developed eye, air pressure less than $950 \, \text{hPa}$, and wind speeds reaching hurricane strength.

Dissipating Stage (Tropical Cyclone)

The final stage where the cyclone moves over land or cooler water, friction slows the wind, and lack of moisture causes air pressure to increase.

Storm Surge

A bulge of sea water pushed toward the shore by the force of swirling winds, which can increase the average water level by $4.5 \, \text{m}$ or more.

Flash Floods

Rapidly occurring events beginning within minutes or hours of excessive rainfall that can reach heights of $10 \, \text{m}$ or more.

Latent Heat

Energy released during large-scale condensation in the atmosphere that makes air more unstable and fuels the rising motion in a tropical cyclone.

Forward Left Hand Quadrant

The most dangerous and destructive part of a tropical cyclone in the Southern Hemisphere because the winds and the Tropical Easterly winds coincide.