The life cycle of a thunderstorm
BRIDGEPORT, W.Va (WDTV) - If you’ve looked outside on a few stormy summer afternoons, there’s a good chance that you’ve seen thunderstorms in all three stages of their life cycle- you probably just didn’t realize it.
There are three main parts to thunderstorm formation and dissipation, and the criteria for these stages depends mainly on the strengths of the updrafts and downdrafts within the storm. Every thunderstorm has an updraft and a downdraft, regardless of its size or type, but what even is an updraft or downdraft?
In the spring and summer, the sun heats up the ground rapidly during the day, causing air near the ground to warm up too. An updraft forms when this warm air rises from the ground up into the higher levels of the atmosphere. As the warm, moist air rises, water droplets are gathered together, and a cloud forms. The condensation process is one that releases heat, so the cloud gets colder and colder as it grows. This acts to strengthen and maintain the updraft until precipitation starts, since the temperature difference between the cloud and ground is increasing- the cloud is getting colder, but the ground is still hot.
Once rain begins to fall out of the cloud, it begins to cool the air at the bottom of the cloud and right beneath it. This cold air at the base of the cloud sinks, which creates a downdraft.
Now that we’ve covered the basics, we can understand how updrafts and downdrafts define the life cycle of thunderstorms.
The first stage is the developing, or cumulus, stage. Here, the updraft is dominant. The constant rapid rise of air helps the cumulus cloud to grow larger and larger, rising tall in the atmosphere, but rain hasn’t started yet. This is when we see those massive, fluffy, anvil shaped clouds that look ominous but not much storm action has happened.
The second stage is the mature (or mature cumulus) stage. Here, the updraft and downdraft are both strong. The contrast between the cold cloud and warm ground continues to fuel the updraft, but the onset of precipitation has begun to cool the air under the cloud, causing a strong, sinking downdraft to develop as well. You may even feel strong, cool winds as the cold air sinks rapidly (this is known as a gust front).
The final third stage is the dissipating stage. Here, the downdraft is dominant. Eventually, the air beneath the storm gets too chilly for the updraft to continue rising, so the downdraft acts to “cut off” the updraft. At this point, the thunderstorm begins to fall apart. Often, this can be seen as a huge expansion at the top of the cloud, since the structure of the cloud is no longer being sustained by an updraft. The clouds and storm begin to dissipate into the atmosphere.
As you know, getting caught out in a thunderstorm is a dangerous thing! Head indoors when you hear thunder or see lightning. From behind your window, happy storm watching!
You can always find more weather facts and updates on social media @annawxgirl or @WDTV5Weather.
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