A few gales and hailstorms will also be possible, according to the Royal Meteorological Institute (IRM), which has placed the country on yellow alert for the day. The situation will hardly improve on Friday since a new storm warning has already been issued. The warning could even change to orange vigilance.
This afternoon, the heaviest showers will give accumulations of 10 to 20 l / m2, specifies the MRI. Over the hours, an improvement will take shape in the west of the country, a few gaps will light up the sky, while the risk of thunderstorms will shift to the east. The maxima will vary between 19 degrees by the sea and 28 degrees in Belgian Lorraine. The wind will be light to moderate.
In the evening, it is mainly in the eastern half of Belgium that the stormy showers will still rage. After a relative calm at the end of the evening or at the beginning of the night, new showers still accompanied by thunderstorms will develop locally south of the Sambre and Meuse furrow. Clearings will be present the first hours. Then, the clouds will become the majority with even the possibility of formation of a fog bank. The minima will be between 10 and 15 degrees, under light winds from various directions.
On Friday, new heavy rains and thundery showers will return quickly from France. “It will be necessary to be particularly attentive to the evolution of the situation because the quantities of precipitation could be much more important in comparison with the first episodes”, warns the IRM.
We will thus be able to exceed, in certain regions, 40 l/m2 in a single hour during the most severe rainy or stormy episodes. Strong gusts of wind may also occur, so the warning may change to orange vigilance. The maxima will vary between 17 degrees by the sea and 27 degrees in Belgian Lorraine, under a weak to moderate westerly wind.
At night from Friday to Saturday, the last rains will quickly evacuate through Germany and the Netherlands and the sky will clear at first. Then, we will witness the formation of low clouds.
Saturday will sound calm, sunny periods will alternate with cloudy periods and the thermometer, falling, will show between 16 and 20 degrees.