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Weather Term Definitions
- Lake Effect Snow: A local intense, narrow band of moderate to heavy snow typically caused by very cold dry air moving over the warmer body of water. It can extend long distances inland, persist for many hours, and may be accompanied by strong gusty surface winds and possibly lightning.
- Land Breeze: A wind that blows from the land towards a body of water. Also known as an offshore breeze. It occurs when the land is cooler than the water.
- La Nina: A cooling of the equatorial waters in the Pacific Ocean. The opposite phase is an El Niño.
- Lapse Rate: The change in temperature with altitude in the atmosphere.
- Latent Heat: The heat energy that must be absorbed when a substance changes from solid to liquid and liquid to gas, and which is released when a gas condenses and a liquid solidifies.
- Leeward: The side of an object away from the direction in which the wind is blowing; downwind; opposite of Windward. Usually used to describe sides of mountain ranges.
- Lenticular Clouds: A cloud that generally has the form of a smooth lens. They usually appear in formation as the result of orographic origin. Viewed from the ground, the clouds appear stationary as the air rushes through them.
- Lifting: The forcing of air in a vertical direction by an upslope in terrain or by the movement of a denser air mass.
- Lightning: A sudden visible flash of energy and light caused by electrical discharges from thunderstorms.
- Likely: In probability of precipitation statements, the equivalent of a 60 or 70 percent chance.
- Low: An area of low pressure, usually accompanied by cyclonic and inward wind flow. Also known as a cyclone.
- Low-level Jet: A region of relatively strong winds in the lower part of the atmosphere.
