Mid Latitude Cyclones

Sectors in a mid latitude cyclone

Mid-latitude cyclones begin as low pressure areas along the polar front (stationary portion) where warm air meets cold air.
The wave develops initiating a separate warm and cold front and pressure starts to decrease.
As the storm intensifies, pressure continues to lower and cyclonic (counterclockwise flow in the N.H.) increases.
At the point of occlusion, the storm is at its greatest strength and will then decrease in intensity after that time.
Storm dissipates and fronts disappear.
These storms travel in a general west to east direction.
Storms last a few days to a week and go through their life cycle as they travel across the U.S.

Where do mid latitude cyclones commonly form? Why?

Mid latitude cyclones commonly form in the winter at the middle latitudes. This is because of the warm and cold fronts form next to each other.

Weather across a mid latitude cyclone

The warm air at the cold front rises and creates a low pressure cell. Winds rush into the low pressure and create a rising column of air. The air twists, rotating counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. Since the rising air is moist, rain or snow falls.

Life Cycle of a mid latitude cyclone

1. stationary front
2. frontal wave
3. open wave
4. mature (initial occlusion)
5. advanced occlusion
6. cut-off cyclone

stationary front--> rising motion along fronts --> warm front moves slowly northward while cold front progresses behind it --> occlusion is when cold front "catches up" with warm front

remember, jet streams are guiding this whole system eastward

Mid-latitude cyclones begin as low pressure areas along the polar front (stationary portion) where warm air meets cold air. The wave develops initiating a separate warm and cold front and pressure starts to decrease

Nor'easter

Macro scale storm along east coast. Gets its name from the direction the wind is coming from. Low pressure, cold, picks up moisture from ocean and can cause massive snowstorms and damage...

mid-latitude cyclone

A cyclone that forms in the middle latitudes at the polar front.

lee side cyclogenesis

The stretching of a column of air as it descends on the lee-ward side of highly elevated terrain such as the Rocky Mountains

Colorado Low

Lee-side low: as westerly winds blow over a mountain range, the air expands vertically on the downwind (lee) side, which can help intensify any pre-existing areas of low pressure

Gulf Low

A Gulf low or Texas Low is a low pressure area that forms or intensifies over the Gulf of Mexico and move northeast on the western side of the Appalachian mountains

occluded front

a front where a warm air mass is caught between two colder air masses and brings cool temperatures and large amounts of rain and snow

Alberta Clipper

Fast moving low pressure area which generally affects Canada and upper Midwest and Great Lakes. Can produce snow and bitter cold winds.