Download - The Midlatitude Cyclone
The Midlatitude Cyclone
Cyclone Developmentbegins with a stationary front
Before Birth
Forecasting where on theStationary front the developmentwill occur is the tricky part!
Nascent stage ofCyclone Development
Birth andadolescence
Mature stageof Cyclone Development
Adulthood
Mature Wave Cyclone
Typical Cold Front Structure• Cold air replaces warm; leading edge is steep in fast-moving
front shown below due to friction at the ground– Strong vertical motion and unstable air forms cumuliform clouds
– Upper level winds blow ice crystals downwind creating cirrus andcirrostratus. Note change in wind and temperature as front passes.
• Slower moving fronts have less steep boundaries and lessvertically developed clouds may form if warm air is stable
Typical Warm Front Structure• In an advancing warm front, warm air rides up over colder air at the
surface; slope is not usually very steep
• Lifting of the warm air produces clouds and precipitation well inadvance of boundary
• At different points along the warm/cold air interface, the precipitationwill experience different temperature histories as it falls to the ground
The Partially OccludedStage beginswhen the cold front starts to overrun the warm front
Middle age
Partially occluded wave cyclone• Cold-occluded front
– Approach bringsweather sequencelike a warm front
– Frontal passagebrings weather morelike a cold front
• Warm-occludedfronts also possible
Cold-occluded front
Relationship between occluded fronts and Midlatitude cyclone development
Mature wavecyclone
Partially occludedwave cyclone
The Occluded Stageis characterized bymore warm air being pushed aloftand the size of thewarm air wedge at the surface decreases significantly
Over theHill
Relationship between occluded fronts and aMidlatitude cyclone
Partially occludedwave cyclone
Occluded wavecyclone
The final decay stageof the cyclone. The warmair is isolated aloft with cold air beneath.
Death
The Wave Cyclone Model(Norwegian model)
• Stationary Front
• Nascent Stage
• Mature Stage
• Partially Occluded Stage
• Occluded Stage
• Dissipated Stage