1. After the snowy episode of November 21 and 22, 2024, can we hope for a few snowflakes for Christmas in Brittany?
Sébastien Decaux. “Until December 26-27, we can see a trend emerging. It can still move. The three models we consult are quite convergent. In Brittany, we would be in an anticyclonic border condition. We are on the eastern flank of the anticyclone with a slight west/northwest flow.
It's not particularly cold. It's even rather sweet. This would give daytime temperatures for December 24 and 25 probably close to 10 to 12 degrees in Brittany. No snow, no frost. Almost seasonal conditions.
Precipitation is not excluded but if there is any it will be rather weak and more on the coasts, less in the interior.
2. Do you remember if there was ever snow in Brittany recently at Christmas?
“December 24, I don’t remember. But on December 25, in 2004, yes. It had snowed in a northern part of Ille-et-Vilaine and the east of Côtes d'Armor in the evening. I was between Dol-de-Bretagne-Dinan and Saint-Malo (35). There was a layer of 5 to 8 cm on the ground.”
3. Snow at Christmas remains unusual…
“Yes, it’s very, very rare and it’s becoming more and more so.”
4. And for the rest of the winter, are there a lot of days of snow on average in Brittany?
“I made a map of the number of days of snow between 1981 and 2010. It was 8 to 9 in the Rennes basin, 6 to 7 days in Brest per year. Previously, at the stations, there were observers who noted what was happening every day. Today, everything is automated and snow observations are rarer. It is only in Quimper, Brest and Rennes that with the stations we can detect snowflakes.”
5. In the coming days, should we still expect cold days?
“This Friday, it will be very cold. We could be between -1 and 2 degrees… It will depend on the sectors. We expect mists, fogs, a little humidity. There are some weather models that see, Friday morning, like snowy drizzle with two or three flakes that could flutter but extremely weakly.
For this weekend, an anticyclone returns. It will be gray and we will have a gradual warm spell, which will not be very clear, with 6 to 9 degrees on Saturday and 8 to 10 degrees on Sunday.
Next week, the anticyclone weakens and we will find that good old windy South-West flow, with rain certainly from Wednesday or Thursday. But no real cold on the horizon.
At the end of next week, there will also be a good westerly wind on the coasts but no storms for the moment.”
