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Some common sense of thunder and lightning

2018-09-03  |   Editor : houguangbing  

Lightning proverbs and lightning early warning. The folk often forecast the weather according to the thunder. "if thunder sings first, the rain will not last", this proverb means that if a thunder occurs before the rain, then the rain which is often called “hot thunderstorm”, is formed by some thermodynamic reasons such as being uneven heated locally. And its regional rainfall is small, the time is very short, and there is another saying, "rain of summer is very strange because here may rain while there may serene”. "Rain first following thunder will meet a strom, neither fast nor slow will see an unbroken spell of wet weather”, “ the thunder is grinding and the rain will pour down the river", these proverbs refer the process that first rain and then comes wind and frowst following the increasingly fierce rainstorm and unceasing thunder which indicates a downpour. If the thunder neither fast nor slow during the rain, there will be continuous rain. "Southwest thunder thunders, heavy rain pours down", indicates that when the thunder is from southwest direction, then the rain will be violent and last a long time. “Northwest thunder thunders, instant water drops”, indicates that when the thunder is from northwest, then the rain will come quicker and end faster, with gale and even hail because of some red cloud. "Northeast thunder thunders, the rainfall is not heavy", "southeast thunder thunders, no rain will down", all these proverbs are based on the direction of thunder to estimate the size of rainfalls.

Identify thunders by clouds. Lightning usually generated in cumulonimbus, or cumulonimbus thunder clouds, which is developed from fair-weather cumulus, cumulus and mane-like cumulus. Having understood the development of cumulus, then you can prepare in advance to prevent lightning after analysising which process it is when you are in the field and see the clouds. Fair- weather cumulus: it is formed when the air convection is not very strong (the vertical velocity is less than 5 meters per second). The shape of the cloud is flat, the top part is slightly arched, and the horizontal width is larger than the vertical thickness. There is a shadow in the middle of thick fair-weather cumulus clouds. Mainly cumulus clouds dispersedly appear when it is clear and sunshiny. This kind of clouds generally indicates that there is a stable gas layer above the cloud cluster, and at least in the next few hours, the weather is pretty good. Cumulus: it is formed when the air convection is very strong (the vertical velocity is up to 15~20 meters per second). In the mature stage, its thickness will reach 4000 ~ 5000 meters, which is greater than the horizontal width, so it is also known as the "tower cloud". Every powerful updraft ascends so that there are many bubble clouds on the top. Therefore, the overlapping of those bubbes form a circular arch in the headpiece of cumulus, like a big cauliflower. Because of dense clouds, cumulus is more lighttight than fair-weather cumulus. And the light is uneven distributed on cloud surface: the sun is shining on some parts that are very bright, while others, are pretty dark. The cumulus clouds sometimes cause shower in the middle and low latitudes. If in the morning, dense clouds show the unstable atmospheric stratification and in the afternoon, cumulus may often develop, and even thunderstorms produced. Cumulonimbus: after the dense clouds being formed, if the air convection is continuously strong, resulting in vigorous vertical development and above the height of freezing which lead to the original thick cauliflower-cumulus’s icing whose clear edges become blurred in some places. Then it is the cumulonimbus stage where always is accompanied with precipitation, including lightning, gust and showery precipitation, hail and other weather phenomena, sometimes tornadoes, and even have a strong external rotation flow in special areas -downbust, which can make the aircraft suffer a crash disaster.

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