Haute-Garonne: a meteorologist explains why this Friday snow is expected in Toulouse
Météo France forecaster in the South-West direction, Thibault Guinaldo announces a continuous drop in temperatures until next Monday, with snowfall on Friday afternoon both in the Toulouse plain and on the Pyrenean peaks.
Internet users are announcing a sudden drop in temperatures in the coming days, what will happen in the Toulouse region?
In Toulouse, temperatures will drop by ten degrees by Friday. This descent of cold air is associated with a rainy depression, therefore there should also be snowfall everywhere and not only on the Pyrenees. This snowy phenomenon will affect all of France to varying degrees. In terms of temperatures, in Toulouse, on Monday, we had 20°C and on Friday we expect around 10°C for the maximum.
And what will the temperatures be in the morning?
In the Toulouse plain, we will end up with minimums around 3°C. Saturday we will be at 2°C and Sunday at 0 or 1°C. And in the afternoon, the barometer will be around 10 degrees. In the mountains, it will of course be colder.
So it will snow again on the Pyrenean peaks?
Yes. The rain-snow limit will be between 300 and 500 meters, which means that beyond 500 meters, we will have snowfall. For the moment, we consider that from 1,000 meters, we will have between 20 and 30 cm of snow. Knowing that the wind will turn with the end of the autan wind and the arrival of a north to northwest flow, this is the direction it takes for the snow to enter the Luchonnais. This Friday, with strong winds, we risk having heavy accumulations of snow and we are not immune to the risk of snowdrifts and gusts on the summits. After the passage of the depression, a tail is set up, with precipitation and cold air. And in Toulouse, snowfall is expected on Friday, at the end of the afternoon, at the exit of the schools. For the moment, we would be on a bleaching of the grounds, without that not holding.
When will it start to get cold?
We are already witnessing a drop in temperatures and this until Friday. And their maintenance is planned beyond the weekend, until Monday.
What will be the consequences on the vegetation?
On coming out of a very mild and very dry period. In recent days, we have been 6°C above normal seasonal highs, so we have seen a start to budding and vegetation. The frost that will arrive at the weekend is likely to have consequences even if they will be less significant than last year, when the drop in temperatures was much more severe and colder. For the moment, we are expecting 3°C on Friday in the plains, and frost in the foothills. And just before the temperature drops, there will be a big influx of humidity. The arrival of frost on this humidity will cause damage to crops.
Is this meteorological episode exceptional?
We will say that it happens, as already last year or in April 1977, when a few centimeters of snow fell in Toulouse. It’s quite classic even if the problem here comes from the fact that this exceptional cold and late episode follows a long, very mild period. In addition, this year we have had a shortage of snow since December.
What is the role of climate change in this phenomenon?
Climate change plays on the phenomenon of early spring with higher temperatures and drought events, but also on the occurrence of more frequent extreme episodes. Consequently, the late frost will have more significant consequences on the plants in advance in their budding.
Will the expected rainfall reduce the risk of drought?
No, because we are going to have a single episode over several days. It should rain a little more. Groundwater levels are low, suggesting an early and severe drought for the summer.