Weather Systems

Flashcards covering key vocabulary from lecture notes on Weather Systems, including atmospheric lifting, clouds, air masses, weather fronts, and hurricanes.

Atmospheric Lifting Mechanisms

Ways in which air is forced to rise, leading to cooling and potential condensation and precipitation.

Convectional Lifting

Atmospheric lifting mechanism where air rises due to surface heating and buoyancy.

Orographic Lifting

Atmospheric lifting mechanism where air is forced to rise as it encounters a topographic barrier like mountains.

Cyclonic (Convergence) Lifting

Atmospheric lifting mechanism where air converges at a low-pressure center and is forced to rise.

Cyclonic (Frontal) Lifting

Atmospheric lifting mechanism where warmer air is forced over cooler air along a weather front.

Latent Heat

Heat absorbed or released during a change of state (e.g., evaporation, condensation) of water.

Cloud-condensation nuclei

Tiny particles in the atmosphere that provide surfaces for water vapor to condense upon, forming cloud droplets.

Cloud

A visible mass of tiny water droplets or ice crystals suspended in the atmosphere, formed when air cools to its dew point in the presence of condensation nuclei.

Cumuliform Clouds

Heaping or puffy cloud types, often associated with vertical development and instability.

Stratiform Clouds

Layered or sheet-like cloud types, often associated with stable atmospheric conditions.

Cirrus

High clouds composed of ice crystals, often appearing thin, wispy, and feathery.

Cirrocumulus

High clouds appearing as small, white, rounded puffs often arranged in rows.

Cirrostratus

High clouds appearing as a thin, whitish veil, often producing a halo around the sun or moon.

Altocumulus

Middle clouds appearing as white or gray patches, sheets, or layers with rounded masses or rolls.

Altostratus

Middle clouds appearing as a gray or bluish sheet or layer, often obscuring the sun or moon.

Nimbostratus

Low to middle layered clouds that produce continuous rain or snow.

Cumulus

Low, puffy, fair-weather clouds with flat bases and distinct outlines.

Stratocumulus

Low clouds appearing as a large, dark, rounded mass or roll, often in a layer or patched together.

Stratus

Low, gray, uniform layered clouds, often resembling fog that does not reach the ground.

Cumulonimbus

Towering, vertically developed clouds, often anvil-shaped, associated with thunderstorms and heavy precipitation.

Advection Fog

Fog formed when warm, moist air moves horizontally over a cool surface, cooling to its dew point.

Radiation Fog

Fog formed when the ground cools rapidly at night, leading to the cooling of the overlying air to its dew point.

Dry Adiabatic Lapse Rate

The rate at which an unsaturated parcel of air cools as it rises, approximately 10°C per 1000m.

Lifting Condensation Level (LCL)

The altitude at which rising air cools to its dew point, and condensation begins to form clouds.

Moist Adiabatic Lapse Rate

The rate at which a saturated parcel of air cools as it rises, typically 5-6°C per 1000m, due to the release of latent heat.

Air Mass

A large body of air defined by its similar temperature and moisture characteristics throughout.

Arctic/Antarctic (A) Air Mass

A very cold, very dry, and very stable air mass originating from polar regions.

Continental Polar (cP) Air Mass

A cold, dry, and very stable air mass originating from high-latitude landmasses.

Maritime Polar (mP) Air Mass

A cold, moist, and relatively unstable air mass originating from subpolar oceans.

Continental Tropical (cT) Air Mass

A hot, very dry, and unstable air mass originating from low-latitude deserts.

Maritime Tropical (mT) Air Mass

A warm, moist, and variably stable air mass originating from tropical and subtropical oceans.

Equatorial (E) Air Mass

A warm, very moist, and unstable air mass originating from oceans near the equator.

Weather Fronts

Boundaries separating different air masses, characterized by changes in temperature, humidity, and wind direction, often leading to weather events.

Cold Front

A weather front where a mass of colder air moves into an area occupied by warmer air, often leading to steep frontal slopes, cumuliform clouds, and intense, brief precipitation.

Warm Front

A weather front where a mass of warmer air moves over a colder air mass, often leading to shallow frontal slopes, stratiform clouds, and light, long-lasting precipitation.

Stationary Front

A weather front where two air masses meet but neither advances significantly.

Occluded Front

A weather front formed when a cold front overtakes a warm front, lifting the warm air mass off the ground.

Midlatitude Cyclone

A large-scale low-pressure system in the midlatitudes, characterized by converging winds, fronts, and often bringing precipitation and changing weather.

Midlatitude Anticyclone

A large-scale high-pressure system in the midlatitudes, associated with clear skies and stable weather.

Hurricane (Tropical Cyclone)

An intense tropical weather system with sustained winds greater than 74 mph, fueled by warm ocean water and the latent heat of condensation.

Hurricane Eye

The calm, clear center of a hurricane, characterized by descending dry air and minimal winds.

Hurricane Eye Wall

The region surrounding the eye of a hurricane where the strongest winds and heaviest precipitation occur.

Storm Surge

An abnormal rise in sea level accompanying a hurricane or other intense storm, caused by strong winds and low atmospheric pressure.

Coriolis Effect

A force resulting from Earth's rotation that deflects moving objects (like winds) and is essential for hurricane formation.

Wind Shear

The variation in wind speed and/or direction over a short distance, which can disrupt the organization of tropical cyclones.

Hurricane Dissipation

The process by which a hurricane weakens and eventually dies out, typically occurring when it moves over cold water or makes landfall.