The last week of meteorological summer will bring a change in weather patterns. While the beginning of the week will be characterized by stability, the arrival of a new DANA towards the end of August will bring intense storms to large regions and a drop in temperatures.
We tell you all the details about the DANA that will make us say goodbye to summer and which areas are most affected.
What is a DANA
We have always heard in the weather that there will be a DANA and that temperatures will drop, there will be bad weather, etc. But many people do not know what a DANA is. A DANA, an acronym for "Isolated Depression at High Levels," is a meteorological phenomenon that It occurs when a mass of cold air at altitude separates from the jet stream and becomes isolated at high levels of the atmosphere. This type of phenomenon can generate conditions of atmospheric instability, leading to heavy rains and severe storms, especially in areas of the Mediterranean.
The DANA is formed when a mass of cold air in the upper troposphere, Normally at altitudes above 5.000 metres, it becomes detached from the jet stream, a fast-moving flow of air that circulates from west to east.. When isolated, this cold air mass interacts with the warmer, more humid air found in lower layers, generating an increase in atmospheric instability. This instability triggers extreme weather events, such as intense rainfall in short periods of time, which can cause flooding and other adverse effects in the affected areas.
DANAs are usually more common in autumn, when the contrast between air and sea temperatures is more pronounced, although they can also occur in other seasons. Due to their unpredictable nature and the amount of water they can discharge in a short time, DANAs represent a significant risk in terms of civil protection and emergency management.
The DANA that will bid us farewell to summer
An increase in precipitation is expected on Thursday, although instability may persist until early September. Relative stability is forecast until Wednesday. The main trend in almost all of Spain will be atmospheric stability until Wednesday. There will be no significant weather events, except for some thunderstorms expected in the eastern part of the country on Tuesday afternoon.
These storms are expected to be mild and may arise in the Betic, Iberian and Pyrenean systems, the latter probably experiencing slightly more intense activity.
On Wednesday, although stability will prevail in most of the country, as the day progresses instability is expected to gradually emerge in a large region of the centre, extending from south to north. At the end of the day, some showers cannot be ruled out. The end of August will be marked by a DANA that will begin to form on Thursday.
The DANA is expected to develop on Wednesday and will be located off the Portuguese coast during the last hours of the day. According to the latest forecasts, this location will cause a significant increase in instability throughout Spain on Thursday.
Early on Thursday, forecasts indicate that a wide region stretching from Andalusia to the Basque Country will experience the development of showers and thunderstorms. The heaviest rainfall is expected to occur mainly in the central part of the country and in the regions of the upper Ebro valley.
Everything indicates that the central and western regions of the country, which extending from Cadiz to Bilbao passing through the Tajo Valley, will be the most affected. These storms have the potential to be severe, particularly with regard to the precipitation accumulations expected, either over a short period or throughout the day. In addition, there is also the possibility of strong wind gusts accompanying these storms.
Storms are expected to expand during midday and afternoon and may intensify as the day progresses. The affected regions will be predominantly the western half and the center, especially affecting areas of Castile and Leon, Castile-La Mancha, Madrid, La Rioja and Navarre.
How long do storms last?
On Friday, central regions of the country will experience repeated rainfall, especially in the early morning hours. In the afternoon, storms are expected to intensify, affecting the northern half of the country more significantly.
During the weekend, although the DANA is expected to diminish and recede, discussions about showers and thunderstorms in several regions of the country may still be relevant. The final evolution of the DANA remains uncertain, so it is difficult to pinpoint specific areas.
The latest forecasts, which involve a significant degree of uncertainty, indicate that Spain may continue to experience instability characterized by storms and showers. In the meantime, Temperatures are expected to remain within the typical ranges for this season.
I hope that with this information you can learn more about the DANA that will make us say goodbye to summer.