Five departments will have to pay attention to the sky in the coming days. Météo-France has indeed placed them this Sunday in orange vigilance “rain-flood” or “floods” in a bulletin issued at 6 am.
The Pyrénées Atlantiques, Hautes-Pyrénées, Haute-Garonne and Ariège are affected by “rain-flood” vigilance. The North, for its part, is on “flood” vigilance for the Helpe Minor river.
A rainy episode until Tuesday
This rain-snow episode, which persists this Sunday in the Pyrenean departments, will initially be weak to moderate (rainfall intensities between 2 and 5 mm / hour), with a rain-snow limit at around 1200-1300 m. altitude. Then, the rains will become more sustained in the evening and at night from Sunday to Monday (rainfall intensities close to 10 mm / hour or even a little more).
This strengthening will be accompanied by a significant warmth from west to east on the Pyrenean chain (rain-snow limit becoming greater than 2,000 m in altitude), the rains then replacing snow in the mountains. The episode will continue like this until Monday followingnoon. Subsequently, the trend will be downward in rainfall intensity, except over the eastern part of the mountain range. The rainy episode should not end until Tuesday during the day.
Traffic probably difficult
The accumulations of precipitation will in fact be substantial over all the Pyrenean departments. On the episode (in 48 hours between Sunday and Monday), we expect accumulations of the order of 40 to 80 mm in the plain, 100 to 130 mm in the foothills, 150 to 200 mm in the mountains, locally 250 mm. Precipitation might cause flooding, unusual flooding of streams and ditches, and overflow of sewerage systems.
Road traffic conditions may be made difficult on the entire secondary network and some disturbances may affect rail transport outside the “main line” network. Finally, power cuts may also occur.
