The storm "Gloria" is the third Mediterranean storm in nine months that breaks historical records

"Gloria" has broken records of all kinds: snow thickness, significant wave height in the western Mediterranean, maximum rainfall collected in 24 hours during the month of January and lightning strikes on a day in the same month.

What has happened in recent years in the Mediterranean area is consistent with the different scenarios of climate change that have been taking place for decades, which warn of increasingly frequent and intense adverse phenomena, although assigning responsibilities to climate change to a single adverse event It requires a more complex and extensive study of attribution.

The Spanish Mediterranean area suffers, for several years, unprecedented storms. This is supported by not only the data recorded by the weather station network of the Meteorology Statal Agency, under the Ministry for Ecological Transition and Demographic Challenge, but, going back in time beyond these records, there are no candidates that allow comparison using historical sources.

These storms, defined as historical for breaking records of one or several meteorological phenomena in large areas consecutively, take us until January 2017 and their intense snowfall in the interior of the Valencian Community and in neighboring provinces, which left tens of thousands of people incommunicado and without basic services, going through the summer of 2018, which broke the summer record of electric shocks, and October 2018, when the tragic flood of Sant Llorenç (Mallorca) occurred in which there were 13 dead; That same month the absolute record of maximum rainfall intensity was recorded in one hour in Vinaròs, with 159.2 l / m2 accumulated.

Three historical episodes

As of 2019, the frequency and intensity of these adverse phenomena categorized as historical seems to have skyrocketed, by registering 3 of them in just 9 months. This trend starts last Holy Week (April 18-22), with a historical unprecedented storm for a month of April in the southeast of the peninsula. Thus, in some coastal areas of Alicante, region of Murcia and southern tip of Valencia, it rained, in just 5 days, 5 times more than it usually rains in a typical April month and twice what it usually rains in A standard spring

Five months later, in September 2019 (September 11 to 15) there is an episode in which 7 people lost their lives as a result of torrential rains. By volume of precipitation, it has been the most important precipitation episode in the Region of Murcia of at least the last 50 years, in extension, intensity and persistence and in the Alicante region of Vega Baja, the one with the highest accumulated rainfall in the regional average of all known, at least since 1879, with 39% more rainfall than the next in volume, which was November 1987.

The extraordinary records of rain, above 300 liters / square meter, broke absolute records of precipitation in a day with much difference from the previous marks in observatories with more than 50 years of data, such as Alcantarilla, Murcia, Cartagena and Ontinyent , and even centenarians like Orihuela.

More recently, this month "Gloria" broke all kinds of records.

"Gloria": a single storm that breaks all kinds of records

"Gloria" was the name with which AEMET baptized a storm that, after reaching the Mediterranean area from the Atlantic, activated notices of the relevant level to deserve to be named. And although "Gloria" took the glory and authorship of the storm that affected us from January 19 to 25, in reality it was a storm, as such, nor was it created by an explosive cyclogenesis process (it did not deepen much and very quickly) Nor was it especially deep. It took two more ingredients to promote one of the most special storms since there are records in the Mediterranean area: over England an anomalous anticyclone was positioned both in intensity (greater than 1050 hPa in its center, the highest value recorded by the service British weather since 1957) as in extension Ministry for Ecological Transition and Demographic Challengewhich, in conjunction with "Gloria", created a very important pressure gradient from which very strong east winds were derived. In addition, our concept map is completed with the entry into the area, prior to the arrival of "Gloria", of humid air of subtropical origin that was subsequently channeled through the storm. Thus, while "Gloria" injected moist air, the anticyclone helped to incorporate colder air from the continent. The result was a very complete winter storm, with bad sea, persistent rains, strong winds, abundant snow, extreme minimums and numerous electric shocks, and unique for accumulating records of all kinds within the same event. In its final phase, the strong instability, caused by the flow of humid air, moved from the Gulf of Cádiz and the Alboran Sea towards the coast generating a line of storms responsible for the intense and persistent rains, which occasionally accompanied by hail (like the one in Marbella and Mijas), they affected the night from Friday 24 to Saturday 25 mainly to the province of Malaga.

Higher waves

If we focus on records, as a result of the maritime storm a historical maximum was obtained, the highest data measured in the western Mediterranean, recorded by the Valencia buoy that marked 8.44 meters of significant height on January 20, a value that exceeds the previous record of 8.15 meters measured by the buoy of Mahón in January 2003 and that remains widely above the previous record registered in that buoy of 6.45 m in 2017. Since the significant height is not more than the average of the third of the elevation of the highest waves, it is estimated that with a record of this value the waves have been able to exceed 13 meters of maximum height. That same day the Dragonera buoy, in the Balearic Islands, also marked a historical maximum with a significant height of 7.97 meters, surpassing its previous record of 6.33 meters in January 2017; At that same time, the buoy, which also records maximum height data in real time, measured a wave of 14.2 meters. In addition, the 21 was the day of January with the highest number of electric shocks, 3,035 lightning strikes within the Valencian Community since the discharge network began to operate, in the 1990s. Ministry for Ecological Transition and Demographic Challenge

"Gloria" has also been characterized by leaving heavy rainfall. Thus, in approximately 5 days (from 00:00 UTC on day 19 to 15:00 UTC on January 23, 2020) 7 stations accumulated more than 300 l / m2, of which one exceeded 400 l / m2: Barx (Valencia) with 433 l / m2, where what has fallen has been four times normal for a whole month of January. In the final phase of the episode, the 21 l / m2 fallen in just 1 hour at the Malaga airport stand out, which show the intensity with which the rainfall in that area fell, or the 264.6 l / m2 collected between on January 22 and 25 in Coín (Málaga). But if we focus on records, the 21st day was key. Thus, innumerable rain records associated with a month of January have been broken: 27 liters / square meter were collected in Barcelonaairport more than the previous record of almost 75 years ago, in Tortosa (Tarragona) twice the previous record was collected Almost 90 years ago, in Daroca (Zaragoza), an observatory with more than 100 years of data, it was practically doubled than the previous record recorded almost 70 years ago, the same date as the record that was broken that same day in Zaragoza.

And finally, of the heavy snowfall we are left with a fact: on the 21st, 86 cm of snow thickness was recorded in Vilafranca (Castellón), exceeding the historical maximum of the series, of 80 cm accumulated on March 7, 1968.

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