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  2. Low-pressure area - Wikipedia

    en.wikipedia.org/wiki/Low-pressure_area

    In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. It is the opposite of a high-pressure area . Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible rain or storms), [ 1 ] while high-pressure areas are ...

  3. Atmospheric circulation - Wikipedia

    en.wikipedia.org/wiki/Atmospheric_circulation

    There, moist air is warmed by the Earth's surface, decreases in density and rises. A similar air mass rising on the other side of the equator forces those rising air masses to move poleward. The rising air creates a low pressure zone near the equator. As the air moves poleward, it cools, becomes denser, and descends at about the 30th parallel ...

  4. Thermal low - Wikipedia

    en.wikipedia.org/wiki/Thermal_low

    The hot air over the land tends to rise, creating an area of low pressure. That creates a steady wind blowing toward the land, bringing the moist near-surface ocean air with it. [ 15 ] Similar rainfall is caused by the moist ocean air being lifted upwards by mountains, [ 16 ] surface heating, [ 17 ] convergence at the surface, [ 18 ] divergence ...

  5. Pressure system - Wikipedia

    en.wikipedia.org/wiki/Pressure_system

    A low-pressure area is a region where the atmospheric pressure at sea level is below that of surrounding locations. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the troposphere. [1] The formation process of a low-pressure area is known as cyclogenesis. [2]

  6. Mesoscale convective system - Wikipedia

    en.wikipedia.org/wiki/Mesoscale_convective_system

    A tropical cyclone is a fairly symmetric storm system characterized by a low pressure center and numerous thunderstorms that produce strong winds and flooding rain. A tropical cyclone feeds on the heat released when moist air rises, resulting in condensation of water vapour contained in the moist air.

  7. Rain shadow - Wikipedia

    en.wikipedia.org/wiki/Rain_shadow

    The condition exists because warm moist air rises by orographic lifting to the top of a mountain range. As atmospheric pressure decreases with increasing altitude, the air has expanded and adiabatically cooled to the point that the air reaches its adiabatic dew point (which is not the same as its constant pressure dew point commonly reported in ...

  8. Warm front - Wikipedia

    en.wikipedia.org/wiki/Warm_front

    The warm air mass behind a warm front is not only warmer, but often (but not always) also higher in humidity than the colder air preceding it. Because of a warm air mass’s higher temperature and thus lesser density, mixing between the two air masses is unlikely. Being light, the warm air mass is unable to displace the cooler air mass and ...

  9. Hadley cell - Wikipedia

    en.wikipedia.org/wiki/Hadley_cell

    Hadley's model of the global atmospheric circulation being characterized by hemisphere-wide circulation cells was also challenged by weather observations showing a zone of high pressure in the subtropics and a belt of low pressure at around 60° latitude. This pressure distribution would imply a poleward flow near the surface in the mid ...