(ilmeteo.it) How was the year that is ending from an atmospheric point of view? iLMeteo.it has reviewed the meteorological data of 2021 to reconstruct the “weather – climatic trends” that have characterized our last 12 months. “A catalog in” weather pills “that tell the past year and help to better understand the phenomena underway, including climate change” says Antonio Sanò, founder of iLMeteo.it “A 2021 that was a year characterized by events at times exceptional: heat peaks, intense precipitations concentrated in very short periods of time, hailstorms that are distinguished by size, tornadoes that are certainly not infrequent and fascinating but frightening sea horns. In short, for those who persist in saying that there are no more mid-seasons: the reality is that we live for a prolonged mid-season, but colored by extraordinary excesses ”.
“It is difficult to attribute to climate change a direct link with hailstorms and tornadoes, as their nature is convective and very localized – specifies Mattia Gussoni meteorologist of the portal – This does not exclude, however, that there is an influence , if only for the simple empirical equation warmer, more precipitable water in the atmosphere, more energy for thunderstorms. This is the fundamental point: with the heat the potential energy involved also increases and above all the thermal contrasts are particularly enhanced, creating a deadly mix for the development of massive storm cells, even up to 10/15 km high. A fundamental role was played by the still very warm sea (up to + 2 ° C above the reference averages of this period), which in fact released enormous quantities of water vapor which then went to condense into clouds and causing then torrential rains “.
Never so much snow
2021 began with an “undecided” winter, which manifested itself with temperatures over 1 degree above the average compared to the thirty-year period 1980-2010 and which even, taking into account all the winters from the beginning of registration, appears to have been the eighth warmest winter in history (iLMeteo.it elaborations on CNR-ISAC data). And the snow? In spite of the stop and go of the ski resorts due to the anti-covid measures, the snow fell softly and copiously “It had been years – says Gussoni – that there was no such abundant snowfall in the Alps”. The record of the last 50 years was recorded in the Central-Eastern Alps and especially in the Tuscan-Emilian Apennines, with a total of over 7 meters recorded at the Segheria Refuge (RE).
Easter Monday with the sun in a cold spring
And if the winter was mild, we can’t say the same about spring 2021. Temperatures below average, with values down by 0.42 ° C and exceptional snowfalls in the Alps between April and May. Note of color: Easter Monday in contrast, no rain, on the contrary the day represented a respite from rain and bad weather, offering the opportunity for trips out of town with mild climate and sunny weather. Truce, however, of short duration: already in the following days a phase with a more winter flavor began with the arrival of a cold front coming from Greenland.
48.8 ° C, the hottest day
The protagonist of the summer was the African anticyclone which repeatedly led to intense heat waves in the Central South and on the islands. This year is the hottest day ever with the mercury column that reaches 48.8 ° C on 11 August in Syracuse. “Not only hot, however – the meteorologist Gussoni still remembers – we will remember the summer of 2021 also for the exceptional storm breaks accompanied by really extreme weather events”. In the last ten days of July, hailstones as big as apples hit the Turin and Mantua areas: ice balls with a diameter of 6 centimeters. In the same period in the Garda area a violent whirlwind struck, which uncovered a middle school and a hotel. Also in mid-July, a tornado in Veneto struck the Asiago plateau. Disruptions also in the Ossola Valley (Piedmont) due to a flood and at Milan Malpensa airport, where an Emirates Boeing aircraft returned in emergency due to a hailstorm that damaged the glass and fuselage.
Never so much rain
Autumn 2021 is also full of exceptional phenomena. Record rainfall (elaborations by iLMeteo.it on Arpa Liguria data) between 3 and 5 October in Liguria, where in the hinterland of Savona, in a fraction of Cairo Montenotte, in the sun 6 hours recorded 496 mm of rain, while Rossiglione, in the Genoese area, in 12 hours 740.6 mm of rain fell. South Italy is no better, where the water has exceeded the warning levels: in 72 hours Catania has accumulated, according to SIAS data, 268.4 mm of rain (the equivalent of 3 months of rain). In the nearby Lentini, always in the same period of time, a total of 341.8 mm accumulated. In Linguaglossa Etna Nord, the total rainfall in 72 hours exceeds 500 mm. All the fault of Medicane, Mediterranean Hurricane, the hurricane that hit Sicily at the end of October. In 48 hours, weather stations recorded 700 to 1,000 millimeters of rain: what generally falls in eight to nine months in those areas. But that’s not all because, it should be said, Sicily returns to the eye of the storm on November 16 when the passage of a dangerous cyclonic vortex unleashes not only torrential rains and hailstorms, but also 15 tornadoes “a truly remarkable event – says Gussoni – worthy of the American plains “.
(ilmeteo.it)