The main incidences occurred in the districts of Beja and Faro which were under an orange weather warning on the 15th of November. The municipalities most affected by the bad weather and where the highest number of incidents recorded (148) due to flooding, was in Olhão and Tavira, in the Algarve.

According to Renascença, the DINA phenomenon is what is said to have caused the horrific flooding we have seen in Spain recently. In just one day, more than 400 litres fell per square meter in Valencia which is twice the maximum ever recorded in mainland Portugal. It rained as much in one day as is normal for the Valencia region to rain in an entire year, with the annual rainfall in Valencia being around 500mm. CNN Portugal announced on the 17 November that the death toll from floods in Spain had risen to 226 people, according to the latest official government figures, which also reported 13 missing.

Credits: Supplied Image; Author: PORTUGAL DECODED ;

The Isolated High Level Depression (DINA) or DANA in Spanish is a meteorological phenomenon that occurs every year, it is important to note that this is not the name of a storm but an intensified version of a “cold drop” (gota fria) which occurs when a mass of warm air collides with a stagnant mass of cold air at an altitude of around 9,000 meters.

A specialist from the Portuguese Institute of the Sea and Atmosphere (IPMA), Ângela Lourenço told Renascença that the cause of the floods in Spain were due to the fall of high volumes of precipitation “in a very short space of time” and that in Portugal “these episodes are not so common.

Another meteorologist at the Portuguese Institute of the Sea and Atmosphere (IPMA) Nuno Lopes told Diário de Notícias on the 14 November, that he refused to compare the heavy rain we have experience in Portugal last week with the extreme floods in Valencia.

In relation to the phenomenon that occurred in Spain, he added that “Comparing the weather in Portugal with what happened in Valencia makes no sense. There is a classic depression influencing the weather but it has different characteristics and is a different air mass. It cannot even be compared in terms of impact”.

Valencia was Valencia, it was a completely exceptional event, in an area where exceptional events usually occur, but this was completely off the scale. In Portugal, we have a situation that has occurred before, in other years. What is expected is that "in the coming days" there will be heavy showers which, according to forecasts, may "occasionally" be accompanied by hail and thunderstorms, especially in the southern areas.

Nuno Lopes adds: "Sometimes, people have no idea what heavy rainfall is, which can happen in 5 or 10 minutes, but 5 or 10 minutes of heavy or very heavy rainfall can be enough to cause flooding in more fragile areas or places with weak drainage, especially in urban areas, because there is no capacity to drain rain water."

History of Flash Flooding

Portugal has experienced devasting floods in the past, with the deadliest natural hazard since the 1755 Lisbon earthquake being the 25 and 26 November 1967 flash flood, which affected the heavily populated metropolitan area of Lisbon as this is where the rain was most intense (over 120mm). Without a proper warning system, according to Ramos and Reis (2002), 700 people lost their lives as a consequence of the floods. Additionally, thousands lost their homes and extensive damage was caused.

Precautions to take during heavy rain

Heavy and persistent rain put districts on alert due to bad weather last week but what should you do in case of heavy rain and risk of flooding? The main checklist includes avoiding crossing flooded areas, paying attention to riverside areas, unblocking drains, being careful of loose objects due to the wind and to take special care when driving or just avoid it generally.

Additionally, if possible stay home and move to higher grounds in the event of flooding, stay away from the sea or parking near to it and keep an eye on civil protection warnings to stay informed. Useful information can be found here: https://www.safecommunitiesportugal.com/find-information/environment-and-weather/storms-and-flooding/

Author

Following undertaking her university degree in English with American Literature in the UK, Cristina da Costa Brookes moved back to Portugal to pursue a career in Journalism, where she has worked at The Portugal News for 3 years. Cristina’s passion lies with Arts & Culture as well as sharing all important community-related news.

Cristina da Costa Brookes