From heat records to snow in a few days: unprecedented differences "for more than 30 years", according to Météo France

This Thursday, we could see Parisians in swimsuits in the parks.

A few were perhaps looking at the weather forecast on their phones ... and then noticed that snow was forecast for this Tuesday.

“Today: 25 degrees full sun.

Next Tuesday and Wednesday: snow and -1?

Who cares about our face there, what is this time?

On Twitter, Florentin did not hide his astonishment at these forecasts.

"What do you mean, it's snowing next Tuesday?"

It's impossible !

"," Snow in Paris on Tuesday, reassure me it's April Fool's Day?

", Other Internet users are also alarmed, when one last has fun:" So if I understood correctly, today I tanned and Tuesday I'm going to snowball?

"

Even if it is rare, this loss of about twenty degrees in five days is not, however, worrying, explains to Parisian François Jobard, meteorologist at Météo France.

“Spring is the season par excellence for these rapid changes,” he assures us.

What are the oldest monthly records broken on Wednesday?

FRANÇOIS JOBARD.

It is impossible to name them all… In total, more than 230 temperature records for the month of March were recorded.

In the oldest stations, such as Paris Montsouris, which opened in 1873, we noted 26.0 ° C against 25.7 ° C on March 25, 1955, or in Besançon (Doubs), we measured 25.1 ° C for the first time since its installation in 1885. The highest record is for Colmar (Haut-Rhin), with 27.3 ° C, just in front of the station of Saint-Maur (Val-de-Marne) which was inaugurated in 1872 and where we noted 27.2 ° C against 26.2 ° C in 1903. It is truly exceptional!

How is such a heat wave explained?

It is comparable to a summer heat wave.

We have a very powerful anticyclone, which has settled over a good part of Western Europe, in a sustainable way, with warm air at altitude and in the lower layers.

In addition to that, we have a southerly current which heats the air mass with lasting sunshine.

All this is conducive to heat records.

It is no coincidence that these records are broken at the end of March, because we gain two hours of sun, practically, between March 1 and 31.

Hey, I have tears in my eyes today it's 25 degrees, full sun and next Tuesday it's snowing?

What is this crazy country pic.twitter.com/hBViLzbqeC

- Ekips🐍 (@ProfesseurAss) March 31, 2021

Should this be seen as a new sign of global warming?

Even if we cannot attribute this particular event, as usual, to global warming, we will tend to break more heat records than before.

We have air masses that are warmer than several decades ago, for identical meteorological situations.

We can be surprised, sometimes, by the disconcerting ease with which we beat so many heat records ...

Morning essentials newsletter

A tour of the news to start the day

Subscribe to the newsletterAll newsletters

READ ALSO>

Climate: 2020, the hottest year ever recorded in France

With, however, snow expected very soon ...

On Monday, a disturbance coming from the British Isles in a northerly current will cause temperatures to drop sharply, with, behind, showers and sleet in Normandy.

A significant risk of snow is forecast as far as the plains, from Monday night to Tuesday.

The conditions will be right to observe flakes and snowfall will occur in the form of showers.

For the regions of the Atlantic and Mediterranean coasts, the probabilities are lower.

Almost all other regions will be affected.

But it is too early to say if this snow will hold on the ground.

Has such a sudden change between heat and snow ever been observed?

Yes, we find the same configuration at the end of March 1989: 25 ° C in Alsace on March 29-30 and there was 4 cm of snow in the Paris region on April 4.

Otherwise, we have to go back to March 25, 1955. Spring is the season par excellence of these rapid changes.

They are not uncommon, although it is true that in recent decades it is less common than before.

For more than 30 years, we had not observed 25 ° C in Paris during this period.

Over the last 60 years, there have been 38 days of snow in Paris in April.

But it is less and less often.

These heat in March are more exceptional than seeing snow in April.

But in the future, it will be more likely to see 25 ° C in March, than snow in April ...

What are the consequences of this sequence to be feared?

We broke heat records for several days and now there will be frost. Fruit trees bloom earlier than average. It is a paradox of global warming: vegetation starts earlier and is more vulnerable. We have milder winters and beginnings of spring, but still frosts that are less severe than before. In the years 1970-1980, the fruit trees waited for the month of May to bloom. Many farmers and producers dread it for next week. We can have -4 ° C locally, it can be catastrophic for orchards and horticulturalists.