• Weather Glossary (K)

    From Daryl Stout@HURRICAN to All on Wednesday, November 04, 2020 00:06:06
    This weather glossary contains information on more than 2000 terms,
    phrases and abbreviations used by the National Weather Service (NWS)...
    the government agency who makes weather forecasts, and issues weather advisories, watches, and warnings, for the United States, and its
    territories.

    Many of these terms and abbreviations are used by NWS forecasters to communicate between each other and have been in use for many years and
    before many NWS products were directly available to the public. It is the purpose of this glossary to aid you in better understanding NWS products.

    ***

    K
    Smoke- Smoke in various concentrations can cause significant problems
    for people with respiratory ailments. It becomes a more universal
    hazard when visibilities are reduced to ? mile or less.

    K AMS
    Cold Air Mass

    K Corona
    In solar-terrestrial terms, of the white-light corona (that is, the
    corona seen by the eye at a total solar eclipse), that portion which is
    caused by sunlight scattered by electrons in the hot outer atmosphere
    of the sun.

    K-Index
    A measure of the thunderstorm potential based on vertical temperature
    lapse rate, moisture content of the lower atmosphere, and the vertical
    extent of the moist layer. The temperature difference between 850 mb
    and 500 mb is used to parameterize the vertical temperature lapse rate.
    The 850 dew point provides information on the moisture content of the
    lower atmosphere. The vertical extent of the moist layer is represented
    by the difference of the 700 mb temperature and 700 mb dew point. This
    is called the 700 mb temperature-dew point depression. The index is
    derived arithmetically and does not require a plotted sounding.

    K-index = (850 mb temperature - 500 mb temperature) + 850 mb dew
    point - 700 mb dew point depression.

    Katabatic Wind
    A wind that is created by air flowing downhill.

    Katafront
    A front where the warm air descends the frontal surface (except in the
    low layers of the atmosphere).

    Keetch-Byrum Drought Index
    An index used to gage the severity of drought in deep duff and organic
    soils.

    Kelvin Temperature Scale
    An absolute temperature scale in which a change of 1 Kelvin equals a
    change of 1 degree Celsius; 0øK is the lowest temperature on the Kelvin
    scale. The freezing point of water is +273øK (Kelvin) and the boiling
    point of +373øK. It is used primarily for scientific purposes. It is
    also known as the Absolute Temperature Scale.

    Kelvin Waves
    Fluctuations in wind speed at the ocean surface at the Equator result
    in eastward propagating waves, known as Kelvin Waves. Kelvin Waves
    cause variations in the depth of the oceanic thermocline, the boundary
    between warm waters in the upper ocean and cold waters in the deep
    ocean. They play an important role in monitoring and predicting El Ni¥o episodes.

    Kelvin-Helmholtz Waves
    Vertical waves in the air associated with wind shear across
    statically-stable regions. Can appear as breaking waves and as braided
    patterns in radar images and cloud photos.

    Kilopascal
    The internationally recognized unit used by the Atmospheric Environment
    Service for measuring atmospheric pressure. Abbreviated kPa.

    Kinetic Energy
    Energy that a body has as a result of its motion. Mathematically, it is
    defined as one-half the product of a body's mass and the square of its
    speed (KE = 1/2 * mass * velocity squared).

    Klystron
    An electron tube used as a low-power oscillator or a high-power amplifier
    at ultrahigh frequencies.

    Knot
    (abbrev. Kt) Unit of speed used in navigation, equal to 1 nautical mile
    (the length of 1 minute latitude) per hour or about 1.15 statue miles
    per hour, or 0.5 meters/sec).

    Knuckles
    Slang for lumpy protrusions on the edges, and sometimes the underside, of
    a thunderstorm anvil. They usually appear on the upwind side of a
    back-sheared anvil, and indicate rapid expansion of the anvil due to the presence of a very strong updraft. They are not mammatus clouds. See also cumuliform anvil and anvil rollover.

    Kp Index
    A 3-hourly planetary geomagnetic index of activity generated in
    Gottingen, Germany, based on the K Index from 12 or 13 stations
    distributed around the world.

    KT
    (Knot)- Unit of speed used in navigation, equal to 1 nautical mile (the
    length of 1 minute latitude) per hour or about 1.15 statue miles per
    hour, or 0.5 meters/sec).

    KTS
    Knots
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