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 precipitation could occur, according to the National Meteorological Agency (AEMET), which issued a “special warning”.
According to the agency’s spokesperson, Rubén del Campo, the instability will increase and the cold air mass is expected to leave rains that could be heavy or very heavy and persistent in the Balearic Islands, in the Levant region and in southern Andalusia, although this is still the case. it is unclear whether it is a DANA or a cold storm (BFA).
In both cases, these are systems isolated from the general atmospheric circulation, explains Del Campo, but the differences between the two phenomena are due to “complex technical problems”, while the effects are similar. In this particular case, moreover, the final position of this mass is more difficult to predict than what happened in Valencia two weeks ago.
What are these differences and what are they due to? Here 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 greater freedom of movement, explains Francisco Martín León, meteorologist and coordinator of RAM (Magazine meteorology fans) at elDiario.es. “It grows in western Norway and reaches the Gulf of Cádiz in two days, but in models it does so erratically; This generates uncertainty, because with each pass, the model of the European Center for Medium-Range Forecasts (ECMWF) places it in different places, explains Martín León.
Is it like the previous one?
“The training course is similar to that of DANA in Valencia,” explains Ángel Rivera, state meteorologist. “It’s not typical, before they come from the Azores to the Gulf of Cádiz, and these cold air masses come from the north.” Its gestation is also linked to the general instability of the jet circulation, both polar and tropical, probably caused by the increase in temperature, he says.
Is it as dangerous as DANA?
We can never say that one is more dangerous than the other, each has its characteristics, emphasizes Martín León. “But the Mediterranean is still warm, because previous storms have failed to cool it, that is, there is still energy with temperatures that can develop heavy precipitation or storm trains.” “It seems like she has less energy than the other one,” Rivera says. “It’s not that supervised, the high-level engine may not be as efficient, but with the DANAS you always have to be very careful.”
It will bring more cold
This time, underlines AEMET, 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 regions will there be more rain?
Although it is still impossible to know how much water it will leave and in which places, AEMET predicts rains over a good part of the northern third of the peninsula, abundant in the east of the Cantabrian Sea, from Tuesday. And most importantly: there will be thunderstorms which could be very heavy 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, which could cause 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 frosts in mountainous areas.
“From Thursday, the uncertainty over the forecasts increases sharply,” warns the AEMET spokesperson. “The areas that receive the most rain will depend on the position of the low pressure area and this cannot yet be determined precisely. The areas with the greatest probability of intense precipitation on Thursday will be the Levant region and southern Andalusia, but this, as we say, will have to be confirmed. “Apparently this has the advantage that from Thursday it seems to move towards the west and the areas of heavy precipitation decrease,” explains Ángel Rivera. “But there remains an easterly wind situation, which also gives the possibility of sometimes heavy rain, due to this convergence of winds, so we should not let our guard down.
So is it a DANA or what is it?
Ángel Rivera believes that it is a DANA that will become a cold storm starting from Thursday, but considers that it is a technical aspect 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 the mid and high levels of the troposphere, the cold storm also manifests itself at low levels.”
There is a technical debate among meteorologists about whether calling all of these phenomena “DANA” will ultimately produce confusion among the general public, similar to that which was intended to be avoided with the use of the term “cold drop”. The key is that “cold drop” always refers to torrential rain and DANA is just the isolated cold air mass at high levels, which may or may not produce torrential rain. And perhaps the problem is that it is always associated with destruction and its use increases the feeling of “false alarm”.
“I’ve always been against names, because they end up complicating things,” says Ángel Rivera, who coined the term DANA in the 1980s. “When we went from ‘gotacold’ to DANA, we didn’t have never thought that would be the case. to have this distribution, there were no social networks,” he says. “I would talk more about situations wind or rain, because a memory ends up being associated with an alarm.
