This year's month of July is remembered for the devastating storms that, especially in its second half, rumbled and caused enormous damage primarily in agriculture, infrastructure, cars, uprooted trees and even claimed human lives, the portal writes. Climate 101.
The storm that developed on July 13 in Slovenia lasted over 12 hours, affected 5 countries (including Serbia) and traveled between 1200 and 1500 km. We classify this storm as one of the longest-lived storms monitored in Europe.
Another record was broken on July 24 when a storm hit the Italian town of Azzano Decimo where a hailstone was found with a confirmed diameter of as much as 19 cm. This is a new European record, and otherwise very close to the world record (20,3 cm).
How does a supercell storm work?
Supercell storms represent a special type of long-lived storm cloud that, due to its specific dynamics, and as we can guess from its name, produces particularly intense products such as heavy rain showers, stormy winds, large hailstones, electrical discharges and even tornadoes.
In the southern part of Europe, and therefore in our regions, for a long time there were conditions for the formation of these storms, such as very warm and unstable air full of water vapor, which is the "fuel" for storms.
Supercell clouds are particularly interesting because of all the types of storms they are able to consume this "fuel" most efficiently. That is why these storms broke some records in the previous weeks.
What's next for us?
Will climate change cause more frequent storms of this type? What we can say for sure now is the following: the planet is warming, and for every 1 degree Celsius there will be 7% more water vapor in the air on average.
This means that the clouds will have more "fuel" to do more damage. What will be the regime of these phenomena in the future, in terms of whether they will appear more often or will be more intense, we still cannot definitively say.
It is important to understand that small changes in the mean such as a 1 degree increase in the mean temperature, which is the limit we have already crossed, cause large changes in the extreme values.
Such episodes are dealt with by the theory of extremes within statistics and represent a science in itself. This is the basic feature of climate change, although "much" will not change in average values, what is characterized by extreme phenomena will change significantly.
Extreme values reflected in heat waves and extreme situations, such as episodes of tropical nights, have already been attributed to climate change, so we can expect the same in the future when it comes to storms, and scientific results already show an increasing trend when it comes to shocks. wind, city size and electrical discharges.
How is it created?
Imagine you were given a challenge to empty a water bottle as fast as possible. If you just turn the bottle upside down, the water will periodically flow, then it won't flow, then it will flow, etc.
Those who know the trick will rotate the water in the bottle in such a way as to create a vortex in it so that the water flowing out is simultaneously replaced by the air flowing into the bottle. The second method turns out to be significantly faster, so we conclude that it is also more efficient.
We can apply a similar analogy to observing different types of storms. The recipe for forming any type of storm is practically the same.
First, the air on the ground floor needs to warm up a lot, which was certainly the case in the previous weeks, and we know that warm air is rarer than cold air, so such heated air tends to move upwards and we say that it has become unstable.
Second, if there is enough "fuel" in that air, i.e. water vapor, there are conditions for the creation of a storm. Namely, thermodynamics tells us that every time water vapor condenses into water or when water freezes, heat is released, and these are processes that certainly happen in clouds, so the development of a storm gets an additional impulse.
The question that arises is whether the storm can effectively use the energy it has available to produce all those harmful products we mentioned earlier? It is by answering this question that we differentiate between single-cell, multi-cell and supercell storms.
What does this storm have that others don't?
In a single-cell storm, the development takes place as follows: an updraft appears, water droplets and ice crystals are formed in it, and then at some point in the same area a downdraft appears with precipitation that weakens the already existing updraft.
In this way, the storm stops its own development and dies down. The entire lifetime of such a cloud is about an hour. Multicell storms consist of a larger number of individual cells that can be oriented in relation to each other so that they use available energy more efficiently and thus last longer.
Supercell storms have one feature that other storms do not. It is a strong wind deflection with height.
In that case, such a structure is formed that the ascending current, which rotates, and the descending current are spatially separated. Such a structure enables a continuous supply of "fuel", i.e. water vapour, from below and precipitation in a downdraft elsewhere, without these two processes opposing each other.
Storms that are formed in this way can live for a very long time (several hours), cause enormous damage, and the energy they have is on the order of the size of an atomic bomb.
Read the entire text at Climate 101.
