Meterologist: Scientist that studies weather.
Moderate risk (of severe thunderstorms): Severe thunderstorms are expected to affect between 5 and 10 percent of the area. A moderate risk indicates the possibility of a significant severe weather episode.
Monsoon: A persistent seasonal wind, often responsible for seasonal precipitation regime.
Overcast: Sky condition when greater than 9/10 of the sky is covered. See Sky Terminology.
Partly Cloudy: Sky condition when between 3/10 and 7/10 of the sky is covered.
Precipitation: Water that falls from the atmosphere to the Earth.
Precipitation: Liquid or solid water molecules that fall from the atmosphere and reach the ground.
Pressure: The force exerted by the interaction of the atmosphere and gravity. Also known as atmospheric pressure.
Relative Humidity: The measured amount of moisture in the air.
Scattered Clouds: Sky condition when between 1/10 and 5/10 are covered.
Severe Thunderstorm: A thunderstorm which produces tornadoes, hail three-quarters of an inch or more in diameter, or winds of 50 knots (58 mph) or more. Structural wind damage may imply the occurrence of a severe thunderstorm.
Showers: Precipitation that is intermittent, both in time, space or intensity.
Slight Chance: In probability of precipitation statements, usually equivalent to a 20 percent chance.
Slight risk (of severe thunderstorms): Severe thunderstorms are expected to affect between 2 and 5 percent of the area. A slight risk generally implies that severe weather events are expected to be isolated.
Southern Oscillation: A periodic reversal of the pressure pattern across the tropical Pacific Ocean during El Nino events.
Storms: A voilent disturbance in the atmosphere.
Storm Surge: A rise of the sea, preceding a storm (usually a hurricane) due to the winds of the storm and low atmospheric pressure.
Sustained Winds: The wind speed obtained by averaging the observed values over a one minute period.
Swells: Ocean waves of regular and longer duration than wind waves.
Temperature: A measure of the energy in the air. The more heat energy in the air, the higher the temperature. As the surface warms in reaction to the sun's heat, it also warms the air above it.
Thunder: The sound that results from the formation of lightning. This burst of lightning expands air around it, producing an effect similar to an explosion, thus creating the noise.
Thunderstorm: A local storm produced by a Cumulonimbus cloud, always with lightning and thunder, and usually accompanied by strong gusts of wind, heavy rain, and sometimes hail.
Tornado: Whirling, funnel shaped cloud.
Tropical Depression: Tropical mass of thunderstorms with a cyclonic wind circulation and winds between 20 and 34 knots.
Tropical Disturbance: An organized mass of tropical thunderstorms, with a slight cyclonic circulation, and winds less than 20 knots.
Tropical Storm: An organized cyclone in the tropics with wind speed between 35 and 64 knots.
Turbulence: Disrupted flow in the atmosphere that produces gusts and eddies.
Typhoon: Serious tropical storms whose winds exceed 74 mph. The origins of a typhoon are found over the tropical and subtropical North Atlantic and North Pacific oceans, usually in the summer and early fall, where humidity and light wind allow the storms to form. The storm is referred to as a hurricane in the Atlantic Ocean and a typhoon in the Pacific Ocean.
Warning Forecast: issued when a particular hazard is "imminent" or already occurring (e.g., tornado warning, flash flood warning).
Warm Front: The leading edge of a warm air mass that is displacing the colder air ahead of it.
Wind Chill: The perceived temperature to the human body based on both air temperature and wind speed.
Winds: Differences in air pressure due to unequal heating of the atmosphere.
Wind Speed: The speed at which the wind is moving in relation to the ground.
Visibility: Visibility is the distance one can see at ground level.