SEVERE WEATHER Weather that may cause property damage or loss of life

THUNDERSTORMS Storm accompanied by rain, thunder, lightning, and strong winds Three distinct stages

FIRST STAGE/CUMULUS STAGE Warm, moist air rises, and the water vapor within the air condenses to form a cumulus cloud

SECOND STAGE/MATURE STAGE Condensation continues as the cloud rises and becomes a dark cumulonimbus cloud Heavy, torrential rain and hailstones may fall from the cloud Strong updrafts continue to rise, downdrafts form as air is dragged downward by the falling precipitation

Third state/dissipating stage Strong downdrafts stop air currents from rising Thunderstorm dissipates as the supply of water vapor decreases

LIGHTNING Clouds discharge electricity during a thunderstorm Released electricity heats the air, the air expands rapidly and produces the loud noise – thunder Lightning is a huge spark that travels within the cloud or between the cloud and the ground to equalize electrical charges

HURRICANES Tropical storm with strong wind speeds of more than 120 km/h Develop over warm, tropical oceans About 700 km in diameter Most destructive storms that occur on Earth Most dangerous aspect is a rising sea level and large waves

TORNADOES Smallest, most violent, and shortest-lived severe storm Forms when a thunderstorm meets high-altitude horizontal winds Generally cover paths not more than 100 m wide Winds in the funnel may reach 400 km/h

BLIZZARDS Blizzards are large snowstorms with high winds. Temperatures below -7°C (20°F); -12°C (10°F) for a severe blizzard Occur across the middle latitudes and towards the poles. Pressure gradient between the low-pressure and high-pressure parts of the storm create strong winds

HEAT WAVE According to the WMO a region is in a heat wave if it has more than five consecutive days of temperatures that are more than 9°F (5°C) above average. A high-pressure area sitting over a region with no movement is the likely cause of a heat wave.

DROUGHT When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. Consequences to drought include dust storms, blown over soils, and wildlife disturbance.

MONSOONS A monsoon is a seasonal change in the direction of the prevailing, or strongest, winds of a region. Monsoons cause wet and dry seasons throughout much of the tropics. Monsoons are most often associated with the Indian Ocean. Monsoons always blow from cold to warm regions.

CYCLONE An area of low pressure characterized by rotating wind that moves toward the rising air of the central low pressure region occur in the South Pacific and Indian Ocean.

ANTICYCLONE a weather system with high atmospheric pressure at its center, around which air slowly circulates in a clockwise (northern hemisphere) or counterclockwise (southern hemisphere) direction. Anticyclones are associated with calm, fine weather.