Key Questions

  • Answer:

    Loss of humidity and energy due to precipitation.


    I am assuming you are referring to a thunderstorm and not a wind storm.

    During storm formation, precipitation forms due to condensation. The water droplets that form from condensation will collide forming larger and larger droplets. In the cases of solid precipitation, a process called the Bergeron process occurs as well as accretion. In either case the precipitation gets larger and larger, until it reaches the point that the gravity acting upon it is greater than the forces that are holding it in the air (updrafts). At this point it falls as rain or snow.

    As the precipitation falls, it is removing water from that part of the storm cloud, as well as creating a downdraft. Obviously, since you need water to make cloud, having the water leave the area is going to stop and reverse cloud formation.

    The downdrafts caused by falling precipitation is going to work against the upward motion of air preventing addition storm formation.

    In the case of a large thunderstorm (supercell), the locations of the downdraft can be separate from the areas of updrafts, thus the downdrafts have almost no effect at all on storm dissipation. In the case of a multi-storm system (several thunderstorms in a row) the downdrafts from the leading thunderstorm can feed into the updrafts of the following storm, so in this situation the downdrafts also do not have much impact on storm dissipation.

  • Answer:

    A hurricane is a very intense tropical low pressure system with wind speeds above 63 kts.


    Water vapor is lower pressure than dry air. As a low pressure moves over the warm ocean, particularly over and long stretch of warm water (called the fetch), evaporating water is going to enter the atmosphere and make that low get stronger (deepen). The warm wet air will rise (as warm air does) and it will get cooler as it goes up (at the lapse rate). Eventually this air will be so cold that it cannot hold all off the water as vapor and there is condensation. This creates cloud.

    Now as the water goes from gas to liquid it releases energy (molecules in a gaseous state have more energy that those in the liquid state). This energy heats the air, which causes the already rising air to get warmer and keep rising. This in turn causes the air to cool and the water to condense, and this cycle feeds itself until the air rises to the point that it is no longer warmer than the surrounding air.

    If the wind through the various heights of the atmosphere are relatively equal, we end up with a situation that the developing storm is able to continue developing at all levels of the atmosphere because it is not getting "blown" over by higher winds aloft. With water vapor being injected into the system from the warm ocean and allowed to freely rise in the column because there is no heights were it is removed from the developing storm by higher winds, the storm can build to much much bigger dimensions.

    By the time the process is done, depending on how long the warm water fetch is and how warm the water is, you can end up with a storm that has more energy in it than 10,000 nuclear bombs. Try flying your kite in that!

  • Answer:



    In very general terms storms are cause by instability in the atmosphere. We all know warm air rises and cooler air therefore sinks. In any situation where you have cold air under warm air things are stable. When you have war air under cooler air you have a situation where the atmosphere is unstable, basically it wants to flip itself over so that the warm air is above the cold air.