Every morning with low temperatures a meteorologist wakes up knowing that he will have to “fight” misinformation and denial with data (and showing great patience). And so, in these days of remarkable decrease in temperatures compared to the anomalous heat (because it is good both to put things in relation and to remember what is anomalous and what is in line with the season) of the previous weeks, together with the snow there are also comments on global warming and the cold at the end of April. Then popularizers and meteorologists like Andrea Coriglianothey roll up their sleeves and work a bit with the many data available, to come up with interesting statistics that, at a glance, tell the reality of the facts.
On his Facebook page, the speaker says: “Today, after a long time, I recorded a cold day: the average daily temperature was 5.2 °C lower than the climatological average. To find a colder day, with a negative difference of 5.8 °C, I have to go back to December 10, 2021, that is, more than two years ago.
And now hold on tight…
Since December 10, 2021, there have been 42 hot days, i.e. those with positive anomalies equal to or greater than 5 °C.
In just over two years, 1 cold day and 42 hot days of this intensity. There’s really no match.”
And who is wondering the reasons for this “cold wave” can be answered in the image below, which represents the temperature at a height of 850 hectoPascals, which corresponds to approximately 1.5 kilometers compared to sea level (for those who are not passionate or accustomed to meteorology: in this field the height above the earth’s surface is measured with pressure, and is therefore expressed in Pascals, and not in metres).
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A post shared by Scott Duncan (@scottduncanwx)
The explanation of the transition “from summer warmth to late winter cold” is provided by Scott Duncan, a well-known Scottish meteorologist, accompanying the image, which we report here translated.
“Much of Europe experiences the full range that April has to offer in just a few days.
The amplified jet stream is a crucial element in bringing cold weather to Europe. Some parts of Europe set impressive heat records earlier in the month.
Values of 20 and even 30 degrees Celsius have been recorded. This heat was quickly followed by a strong coolingwhich brought us back to temperature levels more typical of late winter/early March.
April is a month that often sees the most volatile weather swings. Why? It is a month of transition between the seasons.
The Arctic is still cold and coming out of winter, but the sun is getting stronger and warm air masses are taking on summer characteristics at low latitudes. Europe can import both air masses with the right weather patterns.
This is why we can go from summer heat to late winter cold. Europe is no stranger to cold weather in April, a frequent guest in recent years.”
Tags: years cold day hot match lets fooled cold snow days
