Aviation Weather: Air Masses & Fronts

Air Mass is

High/low pressure

What is air masses and fronts?

A large body of air with general uniform tempature and humidty.

What do air Masses and front range from?

Poles to desert to tropical climates

How are Air masses classified?

By tempature and moisture properties of their source regions.

What does air masses moisture contain of:

Continental ( c ) and Maritime (m)

What does air masses tempature contain of?

Artic (a), Polar (P) and Tropical (T)

What is the High continental pressure?

Continental Polar (cP) - cold, dry

Continental Artic (cA) - cold, dry

How is high pressure characterized?

Cooler, dense air masses causing sinking air (if it cold, its high pressure)

What is the Low continental pressure?

continental Tropical (cT) - warm, dry
Maritime Polar (mP) - cool, moist
Maritime Tropical (mT) - warm, moist

What are fronts?

a boundary or transition zone between different fronts

What are the 5 different front?

Cold front, warm front, stationary front, occluded front, and dry line.

What is warm fronts?

Occurs when a mass of air mass advances and replaces a body of cold air.

What is cold fronts?

Occurs when a mass of cold, dense and stable air advances and replaces a body warmer air.

How fast does warm fronts move

Slow at 10-25 miles per hour

How fast does cold fronts move?

Move fast at 25-30 miles per hour

What is stationary front?

A front that stalls or is moving very slowly over an area.

What is occluded front?

When a cold front will “catch up” to the warm front and will collide with it forms ______

What is cold front occulsion?

Happens when the cloud front overtakes the warm front and the air ahead of the warm front.

What is warm front occulsion?

Occurs when the air behind the cold front is actually not as cold as the cool air mass ahead of warm.

What is a wave cyclone model?

Is low pressure circulation that forms and moves along a front.

First stage is

Stationary: all wave cyclones startes as stationary fronts

Stage two is

Frontal wave: Disturbance or upper level jet streams shifts create a wavelike or bend along the stationary front.

Stage three is

Open wave: Distinct cold & warm fronts become fully organized and seperated by warm sectors

Stage four:

Occluding Stage: The faster moving cloud front catches up to and overtakes the slower warm front.

Stage five:

Dissipation Stage: The surface low - pressure system cut off from its warm air energy source and loses upper level jet stream support.

What is Dry Line?

This is low - level boundary hundreds of miles long seperating a moist air mass and dry air mass.

What is a dry line weather?

Since drier air is more dense than moist air, the dry line forces moist air up into Atmosphere as it moves east.