midlatitude cyclones (storms) extratropical cyclone or wave cyclone or frontogenesis or storm low...

Midlatitude Cyclones (Storms)

• Extratropical cyclone or wave cyclone or frontogenesis or storm

• Low pressure area with counter-clockwise circulation.

• Atmosphere collects water as water vapor in evaporation from oceans, lakes.

• It is returned via precipitation, often caused by storms.

StormsCenter of intense low pressure with

cyclonic circulation and resultant precipitation.

• Midlatitude Cyclone• Hurricane• Tornadoes• Not thunderstorms, no cyclonic

motion.

Cyclogenesis in Action:Mid-latitude (extratropical) cyclones

Air MassesDefinition: volume of air with same temperature and humidity characteristics

Source Regions: where air masses come from.Classification: warm or cold, moist or dry

Air Masses Affecting North America

Frontogenesis

Occluded Front: The Death of a Storm

Occluded Front

Weather Maps

Weather Maps

Today’s Weather Map

Storm Tracks: North America

ActualStormTracks(1991)

Storms (Storm Tracks) generally travel from West to East in North America all year

They shift Northin summer & South in Winter

AverageStorm TracksMoving WestTo East

Midlatitude Cyclone Characteristics

Motion: these storms move across the midlatitudes at about 30 m.p.h. from west to east as they rotate once around a low pressure center.

Size: roughly 1,000 miles in diameter, the largest of storms

Lifespan: 3-6 days to develop, 3-6 to dissipate

Pressure: center roughly 990-1000 mb (1-2 % drop)