Quebec municipalities already hit by flooding are bracing for more wet weather this weekend.

Environment Canada has issued a rainfall warning for much of southwestern Quebec. The warning is expected to remain in effect all weekend.

Officials said the ground is so saturated it has little ability to absorb further rainfall. So far, more than 120 cities and towns across the province are dealing with flooding.

For many, the situation will worsen over the weekend as rain continues to fall.

In the greater Montreal area, wet weather is expected to continue through the weekend. Anywhere between 20 millimetres and 40 millimetres of rain could fall by Sunday.

In the Laurentians north of Montreal, Environment Canada has forecast up to 50 millimetres of rain.

(CBC)

The weather is expected to worsen an already precarious situation for municipalities where water levels have risen significantly in the last week.

On Friday, Public Security Minister Martin Coiteux announced that the Armed Forces will be assisting in the flood zones.

Urgences Québec says more than 1,500 residences across the province have been affected by flooding this week.

Among the hardest hit municipalities are Île Bizard, Île Mercier, Pierrefonds, Sainte-Anne-de-Bellevue, Rigaud and Laval-sur-le Lac.

CBC weather specialist Frank Cavallaro responded to questions live on Facebook.

Frank Cavallaro explains how the rainfall warning will affect people in southern Quebec 4:16

Here is his forecast for the greater Montreal area:

Friday night: More rain and winds. Low near 8 C.

Saturday: Light rain with a risk of thundershowers. Some sunny periods, breezy. High 21 C.

Saturday night: Showers, risk of thundershowers.

Sunday: Scattered showers and cooler. High near 12 C.

Monday: Cloudy skies. High near 9 C.

Faces of the flood: Personal stories from Quebec's hardest-hit zones