Mid-latitude & Tropical Cyclones

Front

What are other names for Mid-Latitude Cyclones?

Back

• Mid-Latitude Depressions

• Frontal depression

• Temperate cyclone

• Sub-tropical cyclone

Front

What is a mid-latitude cyclone?

Back

It is a low-pressure cell accompanied by a warm and a cold front.

Front

What is a front?

Back

The boundary between two air masses with different temperatures and levels of moisture

Front

Where do mid-latitude cyclones occur?

Back

They are found between 40° and 60° latitude in both hemispheres. They are located within the Westerly Wind Belt and move from west to east.

Front

What are the general characteristics of a Mid-Latitude Cyclone?

Back

• Rotation: Clockwise in the Southern Hemisphere

  Speed: Moves at 30-50 km/h

• Lifespan: 4 to 14 days

• Diameter: Can be up to 3000 km

• Isobars: Oval-shaped

• Formation: Can occur in groups called families

Front

Describe the Initial (Formative) Stage of a Mid-Latitude Cyclone.

Back

The cyclone originates at the polar front (around 60° N/S). Friction between the Westerly winds and Polar Easterlies creates a disturbance, forming a wave in the front where a low-pressure cell begins to develop.

Front

Describe the Mature Stage of a Mid-Latitude Cyclone

Back

As air circulates around the low pressure, the polar front separates into distinct cold and warm fronts. The cyclone is fully developed with a warm sector of air between the two fronts.

Front

Describe the Occluded Stage of a Mid-Latitude Cyclone.

Back

The faster-moving cold front overtakes the warm front, lifting the warm sector off the ground. The fronts combine to form an occluded front, which is associated with nimbostratus clouds and rain.

Front

What weather is associated with an approaching Warm Front?

Back

• Temperature: Gradually increases.

• Pressure: decreases (low pressure)

• Clouds: Cirrus clouds appear first, followed by altostratus, stratus, and nimbostratus.

• Rainfall: Light and steady rain can last for a couple of days.

• Wind: Wind direction "backs" (shifts) from Northeast to Northwest.

Front

What weather is associated with a passing Cold Front?

Back

• Temperature: Drops abruptly.

• Pressure: Drops just before the front and rises again after it passes.

• Clouds: Cumulonimbus clouds form.

• Rainfall: Heavy, intense rain occurs over a smaller area, sometimes with thunderstorms or snow.

• Wind: Wind direction "backs" (shifts) from Northwest to South-Westerly.