It’s called trough and it arrives this Thursday to finally cool us off in this suffocating summer, and to be able to enjoy more bearable nights, even cold ones, in some areas. After enduring the hottest month on Earth since there are records, August begins with a heat truce in half of Spain.
A truce that will be brief but intense thanks to the arrival of this meteorological phenomenon called trough that The temperatures will plummet during Thursday and Friday in a good part of the country. So much so that, as Rubén del Campo, spokesman for the State Meteorological Agency (Aemet), points out, “the drop in maximum temperatures will be between 5 and 10 degrees compared to normal this month, so they will be more typical end of May or beginning of June”.
In certain areas, the drop could reach 12 degrees. “It is a significant drop in temperatures. Andn some places, such as the northeast of the Peninsula, it will be an extraordinary descent, and they will be quite low for this time of year. They really are rare,” he says.
The bad news, he adds, is that at the southern end of the peninsula in the south of Extremadura and especially in Andalusia, it will continue to be very hot and you will barely notice that thermal relief. “It is likely that the highs will not drop below 37 or 38 ºC in the Guadalquivir valley, nor 35 ºC in the province of Badajoz,” says Mar Gómez, a meteorologist for eltiempo.es. “In Córdoba they will go from 41 ºC on Wednesday to 40 ºC on Thursday and 39 ºC on Friday, so they will continue with a very warm environment,” says Del Campo.
But what is a trough and why are temperatures going to drop so drastically? “It is a region of the atmosphere in which the pressure is lower with respect to the neighboring regions. that are located at the same level, and normally appears in the middle and upper levels of the troposphere. Why are they produced? We know that the atmospheric circulation in these latitudes is governed by the polar jet stream, which is a current of very intense winds that circulate at high levels of the troposphere, from west to east. Sometimes this jet stream undulates, waves are formed, and cold air remains in the valleys of these waves, giving rise to these troughs. At the crests of these waves, warm air remains that gives rise to ridges,” explains the Aemet spokesman.