Fluctuating temperatures before a sharper cooling
Meteorological winter officially began on December 1st in France. However, the atmosphere is not really wintery in our country, particularly in the South and West where mildness records were even broken this Sunday.
Temperatures are expected to fluctuate in our country in the coming days. A temporary cooling is in fact expected between Tuesday and Wednesday with the temporary shift of the flow to the North-West, bringing temperatures once again below normal for the period over a large part of the country, particularly between the North and the East.
Subsequently, a new mild spell should affect our country between Thursday and Friday with the once again temporary shift in the flow to the West/South-West.
Evolution of temperature anomalies at 2m over Europe between December 2 and 7, 2024 – Via TropicalTidBits
However, it is from the end of the week that the situation should evolve more clearly at altitude. The Azores anticyclone should in fact weaken towards the South, leaving the field open to a more low-pressure influence and above all a new shift in the flow aloft.
Indeed, a low pressure area should isolate itself during the weekend between Italy and Central Europe, inducing yet another change in flow at altitude. This should indeed shift to the North-West, then to the North and finally to the North-East by the start of next week.
Situation envisaged for Sunday December 8, 2024 in Europe – Modèle GFS via WX CHARTS
Thus, a much colder air mass coming from Northern Europe should be advected towards our country with this new shift in the flow at altitude with a much more wintry feeling increasing by the very end of the week.
Animation of temperatures at 850hPa over Europe from December 4 to 9, 2024 – Modèle GFS via WX CHARTS
For the moment, the situation does not seem favorable to the occurrence of a more or less notable snowy episode in the plains between the end of the weekend and the beginning of next week despite increasing cold air. High pressure should in fact assert itself over the Atlantic from the start of next week, which will mean that the air mass should quickly dry out while the cold will increase.
However, showers should still occur over a large part of the country during this period, accompanied by slush/sleet falling as far as the plains between this Sunday, December 8 and the beginning/middle of next week. The most notable snowfall should be observed on the reliefs, sometimes falling at low or even very low altitude (to be monitored).
Risk of snow in France between the end of the weekend and the middle of next week – Weather-Cities
This risk of snow will however remain to be confirmed in the coming days, small shifts in the main action centers still being possible given the distant deadline.
A persistent cold afterwards?
According to the latest models, this cold and wintry weather is expected to persist at least until the middle/end of next week in France with the establishment of a continental flow over our country.
Temperature anomalies at 2m over Europe for the week of December 9 to 15, 2024 – ECMWF
However, this cold should remain mostly dry due to the return of high pressure to our country. We will nevertheless monitor the possible isolation of cold drops in the Mediterranean, the positioning of which could condition the return of wetter conditions and therefore snow potential during the week of December 9 to 15.
The main forecast models are in fact not in agreement at the moment on the evolution of these potential cold drops. The European ECMWF model envisages, for example, an isolation of this cold drop on the Iberian Peninsula, inducing gentler but also wetter rises via the Mediterranean with a temporary snow potential going towards the Center of France.
Situation envisaged by the ECMWF model for the midweek of December 9 to 15, 2024 – via WX CHARTS
The American GFS model sees this cold drop isolating itself towards Italy, which would lead to much drier weather and also more lasting cold over the whole of France under the influence of the continental flow.
Situation envisaged by the GFS model for the midweek of December 9 to 15, 2024 – via WX CHARTS
The situation therefore remains uncertain for next week, depending on the exact placement of these potential cold drops over southern Europe. In any case, a temporary but fairly notable return of more wintry conditions is expected between this weekend and the beginning of next week with significant snow potential, particularly present on our hills.
