A new mass of cold air will reach the peninsula from northern Europe starting this Tuesday and will cause a new storm in which heavy rainfall may occur, according to the State Meteorological Agency (AEMET), which has issued a “warning.” special”.
In the words of the agency’s spokesperson, Rubén del Campo, instability will increase and the cold air mass is expected to leave rains that could be strong or very strong and persistent in the Balearic Islands, an area of the Mediterranean coast and southern Andalusia, although It is not yet clear whether it is a DANA or a cold storm (BFA).
In both cases they are systems isolated from the general atmospheric circulation, explains Del Campo, but the differences between both phenomena are due to “complex technical issues”, while the effects are similar. In this particular case, furthermore, the final position of this mass is more difficult to predict than what occurred in Valencia two weeks ago.
What are these differences and what are they due to? These are the keys:
More freedom of movement
The destructive DANA of Valencia remained static in the Gulf of Cádiz and was “super isolated, surrounded by anticyclonic structures”, but this isolated cold storm has a greater degree of freedom when it comes to moving, explains Francisco Martín León, meteorologist and coordinator of RAM (Magazine of Meteorology Fans) to elDiario.es. “It is developing in western Norway and in two days it reaches the Gulf of Cádiz, but in the models it does so erratically; That generates uncertainty, because in each pass, the model of the European Center for Medium-Term Forecasting (ECMWF) places it in different places, says Martín León.
Is it like the previous one?
“The training path is similar to that of DANA in Valencia,” explains Ángel Rivera, state meteorologist. “It is not typical, before they came from the Azores to the Gulf of Cádiz, and these cold air masses come from the north.” Its gestation also has to do with the general instability of the circulation of the jets, both polar and tropical, something that is presumably caused by the increase in temperature, he says.
Is it as dangerous as DANA?
You can never say that one is more dangerous than the other, each one has its characteristics, points out Martín León. “But the Mediterranean is still warm, because the previous storms have not managed to cool it, that is, there is still energy with temperatures that can develop heavy precipitation or trains of storms.” “It seems like she has less energy than the other,” says Rivera. “It is not so boxed in, the high level motor may not be as efficient, but with the DANAS you always have to be very careful.”
It will bring more cold
This time, the AEMET points out, temperatures will drop significantly between Tuesday and Wednesday and with them the snow level, which could be around 800 or 1,000 meters in the north of the peninsula on Tuesday and Wednesday.
In which areas will there be more rain?
Although it is still impossible to know how much water it will leave and in what places, the AEMET predicts rain in a good part of the northern third of the peninsula, abundant in the eastern Cantabrian Sea, starting on Tuesday. And the most relevant thing: there will be stormy showers that could be very strong on the Mediterranean coasts of the Levant and in the Balearic archipelago. “30 or 40 liters per square meter could accumulate, especially in the Balearic Islands, in just one hour and this could lead to some flooding in low-lying areas,” warns Rubén del Campo. All this with snowfall in the Pyrenees, the Cantabrian Mountains and the north of the Iberian system, lower temperatures, northerly winds and frost in mountain areas.
“As of Thursday, the uncertainty in the forecast increases greatly,” warns the AEMET spokesperson. “The areas that will receive the most rain will depend on the position of the low pressure area and this cannot be determined precisely yet. The areas with the greatest probability of intense precipitation on Thursday will be the Levante area and southern Andalusia, but this, as we say, will have to be confirmed.” “Apparently, it has the advantage that starting Thursday it seems to be going west and areas of heavy rainfall decrease,” explains Ángel Rivera. “But there remains a situation of east wind, which gives the possibility of sometimes heavy rains as well, due to this convergence of winds, so it is advisable not to let our guard down.
So is it a DANA or what is it?
Ángel Rivera believes that it is a DANA that as of Thursday will become a cold storm, but believes that this is a technical aspect that is indifferent to the general public. The difference with a cold storm, explains Rubén del Campo, is that “while the low pressures associated with a DANA appear mainly at medium and high levels of the troposphere, the cold storm also manifests itself at low levels.”
Among meteorologists there is a technical debate about whether calling all these phenomena “DANA” will end up producing confusion in the general public similar to what was intended to be avoided with the use of the term “cold drop.” The key is that “cold drop” always refers to torrential rains and the DANA is only the cold air mass isolated at high levels, which may or may not produce torrential rains. And the problem may be that it is always associated with destruction and its use increases the feeling of “false alarm.”
“I have always been against names, because they end up complicating things,” says Ángel Rivera, who was among those who coined the term DANA in the 1980s. “When we changed from ‘gotacold’ to DANA, we never thought it would be to have that dissemination, there were no social networks,” he says. “I would talk more about situations of winds or rain, because it ends up being associated with a memory of an alarm.”
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