The main weather models show a weakening of the polar vortex at the beginning of February. Could it add to the cold on France? Explanations.
France has fully entered winter since the beginning of the week. It snowed in the south-west, particularly in Paris and Brittany. This Sunday morning, frosts were almost generalized across the regions. The weather will remain cold next week at least until Thursday.
Could it be much colder in February? The media asks this question by highlighting the weakening of the polar vortex. La Dépêche takes stock.
What is the polar vortex?
The polar vortex is a huge cold zone that arises over the North Pole at an altitude of about 30 km in the stratosphere: it is a band between 15 and 50 km above sea level of our heads. In the heart of winter, strong winds circulate rapidly from west to east, keeping the polar vortex in place until spring, explains Météo France.
Does he really get weak?
A weakening of the stratospheric polar vortex is confirmed by meteorologists. In this situation, a phenomenon called “sudden stratospheric warming” causes temperatures to rise at altitude, alters the circulation of strong winds around the polar vortex, and allows cold air to reach regions unaccustomed to freezing cold, and therefore potentially towards Europe.
?GFS scenario for early February. Pronounced warming of the stratospheric polar vortex, its destabilization and increase in the potential for #cold.
Good. The appointment is too far away. Impossible to determine what will happen. It will remain relevant to watch. pic.twitter.com/3BhBqlQkIL— Guillaume Jauseau (@GJauseau) January 18, 2023
What is planned for February 2023?
It is still impossible to say whether a freezing cold could ravage France in February. “It is far too early to know which exact part of the hemisphere will be affected by a risk of a cold spell,” Gaëtan Heymes, forecaster at Météo France, told La Dépêche. “France is tiny on this scale”.
What are the four-week weather trends?
These weather trends are just a guide. They may be confirmed or invalidated depending on more accurate forecasts. The Weather Channel indicates that the week of January 23-29 will be cold with dry weather. From January 30 to February 5 the weather looks calm with a gradual thaw. Beginning February 6, an ocean current could bring showers and temperatures above normal for the season, with the exception of the Mediterranean Sea.
Has this phenomenon occurred in the past?
France experienced this situation in February 2012. Extremely cold continental air masses had caused temperatures of -10°C to -14°C in several regions, locally up to -18°C. Days without a thaw, including in the south, had occurred with sustained winds and snowfall at low altitudes.