Cold drop or meteorological Dana: what is it, how it is formed and consequences

Cold drop or meteorological Dana: what is it, how it is formed and consequences

By Dr. Kyle Muller

Surely you have ever heard someone mention the term of cold drop or Dana (isolated depression at high levels), especially if you live in Spain or are aware of the news there. What does “the cold drop” mean? A cold drop or Dana is a large mass of low temperature air that has separated from a polar jet. This atmospheric phenomenon causes meteorological instability, a decrease in temperatures and produces storms and floods. In this ecology article, we will talk about What is cold drop or Dana Meteorologicalhow it is formed and its consequenceswhich can become devastating.

What is a meteorological dana or cold drop

According to the State Meteorology Agency, a cold drop or Dana (Isolated depression at high levels) is one Great mass of air at low temperature that has separated from a polar jet. This, when you meet warmer climate areasinteracts with the highest temperature air in the area and It originates storms of all kinds and meteorological instability, being able to cause, among other things, winds of up to 100 km/hey.

It is more common to occur in coastal areas next to warm waters, since the air loaded with moisture that ascends from these warm seas promotes the formation of these cold drops when it meets polar jets. This is the case of, for example, the Mediterranean coast. In addition, Dana can have quite large diameters, up to several hundred kilometers.

Cold drop or meteorological dana: what is it, how it is formed and consequences - what is a weather or cold drop

How the meteorological dana or cold drop is formed

To talk about the formation of the cold drop, the concept of Polar jet. This is one Very cold air current which occurs around one of the two poles on the planet. It is a current with a great force and little thickness, hence its name of jet, which can travel to more than 180 km/h. They are given to an altitude of between 7 and 12 km above sea level and its shape tends to wind based on concrete climatic conditions.

When one of these polar jets comes into contact with the Warm winds From areas such as the Mediterranean, it occurs to sometimes a part of that stream “breaks” or separates from the original current. When this happens, that mass of cold air is trapped between warmer currents, giving the call cold drop or dana.

Of course, this does not always happen, and certain atmospheric circumstances are necessary for a part of that polar jet to separate. It is more common for these circumstances to be given, for example, in summer, since the horizontal thermal gradient is less and is easier for the polar jet to give rise to more turns and meanders in his career, which makes it easier for one of them to end up closing and isolate himself. For example, on the Mediterranean coast, the vast majority of these phenomena are registered between September and November.

Effects of cold drop or Dana

The Dana does not have a fixed duration and its effects are prolonged until the cold air is mixed with the surrounding warm air and dissolves or, until the cold air bag is reinstated to the polar jet from which it separated.

Among the effects of cold drop or Dana are included torrential rains that can cause the River overflow and water channels, Floods, thunderstorms and high speed winds and force, which on the coasts can be accompanied by dangerous swell.

Here you can learn about torrential rain: causes, consequences and what to do.

Cold drop or meteorological dana: what is it, how it is formed and consequences - effects of cold drop or dana

Caution measures in case of cold drop or Dana

Given the effects of a cold drop, a whole package of measures to be taken is recommended if you are in a cold drop zone:

  • Before torrential rains it is necessary get away from any water channelespecially if it is close to low areas.
  • It is also necessary go down.
  • Avoid crossing flooded areassince there is no way of knowing the true depth of water or its strength until it is too late to avoid it.
  • In case of thunderstorms, it is better to stay inside the car or near buildings And if you are in open field, then we have to avoid trees and metal constructions, such as a fence, which can conduct the electricity of a lightning to a lot of distance. Here you can read about the thunderstorms: what are, how types and consequences are formed.
  • Faced with strong winds, you always have to get away from the coast, reinforce the doors and windows and get away from cornices and balconies on the street, since old or weak constructions can give in.

Cold drop or Dana in Spain

Dana is a recurring weather phenomenon in the Mediterranean basin, especially during the months of September, October and November. In Spain, cold drop most frequently affects regions center, east and south of the country. The State Meteorology Agency (AEMET) issues alerts and notices before the imminence of this phenomenon, classifying them by risk levels (yellow, orange or red) depending on the planned intensity of rainfall and possible damage.

In recent years, cold drop has left a significant mark on the meteorological history of Spain, causing floods, overflows of rivers, numerous material damage and deaths.

  • 2019: A weather Dana affected the Valencian Community and Murcia, causing floods.
  • 2021: caused damage to the cities of Toledo and Lepe.
  • 2023: At the beginning of September, a great magnitude affected much of the Iberian Peninsula, with accumulated record precipitation in some areas and serious floods in Madrid, Castilla-La Mancha and other regions.
  • 2024: It is one of the most devastating events in recent years. On October 29, an exceptional intensity hit the Valencian Community, especially the province of Valencia, causing historical floods and more than 200 fatalities.(1) The precipitation accumulated in a few hours exceeded all the previous records, causing the overflow of rivers and ravines and the collapse of infrastructure. The city of Valencia and its surroundings suffered catastrophic damage, with hundreds of deaths and missing.

To expand this information about the weather Dana, we recommend knowing better the causes and consequences of floods and why trees attract rays.

If you want to read more articles similar to Cold drop or meteorological Dana: what is it, how it is formed and consequenceswe recommend that you enter our category of meteorological phenomena.

References
  1. Eldiario.es. (November 12, 2024). The number of deaths in the Dana in Valencia grows to 215 while 17 missing people are left. Available at: https://www.eldiario.es/comunitat-valenciana/crece-numero-fallecidos-dana-valencia-215-quedan-17-personas-desaparecidas_1_11814509.html
Kyle Muller
About the author
Dr. Kyle Muller
Dr. Kyle Mueller is a Research Analyst at the Harris County Juvenile Probation Department in Houston, Texas. He earned his Ph.D. in Criminal Justice from Texas State University in 2019, where his dissertation was supervised by Dr. Scott Bowman. Dr. Mueller's research focuses on juvenile justice policies and evidence-based interventions aimed at reducing recidivism among youth offenders. His work has been instrumental in shaping data-driven strategies within the juvenile justice system, emphasizing rehabilitation and community engagement.
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