Warming will increase after the weekend
The first element of consensus today is the gradual return of warmer weather after the July 4th and 5th weekend.
After a few breathable days, the anticyclone should rise again over Western Europe, contributing to the rise of subtropical air from the Iberian Peninsula and Maghreb. Temperatures will therefore begin to rise again across much of France, first in the south and then towards the center of the country.
In this regard, the main forecasting models are relatively well agreed upon.
Two different scenarios for next week
Especially from Monday, July 6th, differences become apparent.
The US GFS model currently favors a particularly hot scenario. He sees a new wave of Saharan air quickly reaching France with anomalies locally exceeding +15-+17°C at an altitude of about 1500 meters. In this configuration, temperatures in many regions could again reach or even exceed 35°C, with the risk of a heat wave if the heat wave continues for several days.
GFS air mass anomaly © LKM
Conversely, the European CEP (IFS) model suggests a more moderate scenario. The heat will be present, especially in the southern half and center of the country, but the influence of the ocean will be more persistent near the English Channel and in the north-west. Then extreme heat will be less common and likely shorter lasting.
The differences relate to intensity… but most of all, duration.
Contrary to what we may read on some social media, the patterns are not completely opposite.
Now everyone expects the temperature to rise further. On the other hand, they still differ greatly in three main ways:
– heating intensity
– its geographical distribution
– its duration
However, it is these three criteria that qualify an episode as a heat wave or heat wave.
It is therefore too early at this stage to announce with certainty a new episode comparable to the one we have just experienced.
COEP heat © LKM
Can we already talk about a heat wave?
Even if some scenarios are becoming more favorable for another heat wave, it is still too early to talk about a heat wave for the week ahead.
The reliability of the model decreases significantly after five to seven days, especially when the forecast depends on the precise location of centers of action and Atlantic depressions.
On the other hand, the signal for continued very hot weather, especially in the south and west from the beginning of next week, is gradually strengthening. The next few days will determine whether this heat wave becomes a new heat wave in the country.