Severe weather and hurricanes

Latent Heat

Heat absorbed or released during phase changes.

Sensible Heat

Heat that can be sensed or measured.

Energy Transfer

Movement of energy via conduction, convection, radiation.

Albedo

Reflectivity of a surface affecting energy absorption.

Troposphere

Lowest atmospheric layer, where weather occurs.

Convection Cell

Rising and sinking air due to temperature differences.

Low Pressure

Air rises, cools, and forms clouds.

High Pressure

Air descends, leading to clear sky conditions.

Coriolis Effect

Deflection of moving objects due to Earth's rotation.

Polar Cell

Atmospheric circulation cell from 60 to 90° latitude.

Ferrel Cell

Circulation cell between 30 and 60° latitude.

Hadley Cell

Circulation cell from 0 to 30° latitude.

Low Pressure System

Counterclockwise wind movement in the Northern Hemisphere.

High Pressure System

Clockwise wind movement in the Northern Hemisphere.

Air Mass

Large volume of air with distinct properties.

Front

Boundary between two different air masses.

Cold Front

Forms when cool air moves into warm air.

Warm Front

Forms when warm air moves into cool air.

Jet Stream

Fast air currents influencing weather patterns.

Cumulus Clouds

Puffy, fair-weather clouds indicating stable conditions.

Cumulonimbus Clouds

Tall, dark storm clouds associated with severe weather.

Stratus Clouds

Low clouds forming in uniform layers.

Altocumulus Clouds

Mid-level clouds indicating instability in the atmosphere.

Cirrus Clouds

High clouds made of ice crystals.

Thunderstorm Development

Requires moisture, temperature gradient, and updraft.

Cumulus Stage

Initial stage of thunderstorm with growing cumulus cloud.

Mature Stage

Thunderstorm stage with intense precipitation and downdrafts.

Dissipative Stage

Thunderstorm weakens, precipitation decreases, cloud dissipates.

Severe Thunderstorm

Classified if wind over 90 km/h, hail > 1.5 cm, or tornado.

Wind Shear

Differences in wind speed/direction over an area.

Mesoscale Convective Complexes

Large clusters of self-propagating storms lasting over 12 hours.

Squall Lines

Long lines of storm cells, average 500 km long.

Drylines

Boundaries separating air masses differing in moisture content.

Supercells

Violent storms that spawn most tornadoes, last 2-4 hours.

Downbursts

Strong downdrafts generating straight-line windstorms called derechos.

Microbursts

Smaller downbursts, more common than derechos, hazardous to aviation.

Hail

Round ice pieces from thunderstorms, can cause property damage.

Lightning

Electric discharge in thunderstorms, majority occurs within clouds.

Thunder

Shock wave caused by rapidly heated air from lightning.

Fork Lightning

Common type of lightning, appears forked in shape.

Sheet Lightning

Most common, occurs within clouds, not visible externally.

Ribbon Lightning

Appears as a ribbon-like flash, often in storms.

Ball Lightning

Rarest type of lightning, appears as glowing sphere.

Bead Lightning

Appears as a series of bright beads along a lightning stroke.

Lightning Rods

Devices placed on buildings to protect from lightning strikes.

Tornado

Vortex extending from cloud to ground, hazardous when touching ground.

Tornado Diameter

Most tornadoes range from 100 to 600 meters wide.

Tornado Wind Speed

Typically 20 to 40 knots (40 to 75 km/h).

Tornado Stages

Includes organization, mature, and shrinking stages.

Doppler Radar

Used to detect clouds and make short-term weather predictions.

Tornado Watch

Indicates possibility of tornado development.

Tornado Warning

Indicates tornado has been spotted, take action.

Ice Storms

Prolonged freezing rain, occurs during winter near warm fronts.

Blizzard Conditions

Winds over 40 km/h, visibility less than 1 km.

Wind Chill

Cool air evaporates moisture, increases frostbite risk.

Extreme Cold

Temperatures below -45°C in far northern Canada.

Lake Effect Snow

Snow from cold air over warmer Great Lakes.

Drought

Extended low precipitation causing water shortages.

Dust Storms

Windstorms transporting sediments, visibility under 800 m.

Sand Storms

Transport sand close to ground in arid regions.

Heat Waves

Prolonged heat, 5°C above normal increases illness.

Tropical Cyclones

Large rotating low-pressure systems with strong winds.

Hurricane

Tropical cyclone in Atlantic and eastern Pacific.

Typhoon

Tropical cyclone in western Pacific north of equator.

Cyclone

Tropical cyclone in Indian Ocean and southern Pacific.

Tropical Depression

Winds less than 61 km/h (38 mph).

Tropical Storm

Winds between 61-120 km/h (38-74 mph).

Hurricane Season

June 1 to November 30 annually.

Hurricane Destruction

High winds, intense rainfall, storm surge causes fatalities.

Eyewall

Innermost cloud band with highest winds and rainfall.

Eye of Hurricane

Calm center, narrow at surface, wider above.

Hurricane Naming

Names assigned when winds exceed 63 km/h (39 mph).

Hurricane Watch

Likely hurricane within 36 hours.

Hurricane Warning

Hurricane expected within 24 hours or less.

Forecasting Tools

Includes satellites, aircraft, Doppler radar, buoys.

Computer Models

Predict hurricane progress, improve storm tracking.

Public Awareness

Improved education reduces hurricane-related fatalities.

Emergency Preparedness

Prepare homes, obtain flood insurance, plan evacuations.