Heavy rainfall is expected within the next few days across much of Southern Alberta.

Ahead of the downpour, flood watches and high streamflow advisories have been issued for areas in the Foothills.

The Alberta River Forecast Centre issued flood watches for the Highwood River from the Town of High River to the Bow River Confluence as well as Fish Creek.

A high streamflow advisory is also in place for the Highwood River upstream of the Town of High River.

Their advisory says the Bow River Basin could see as much as 90-150mm of rain, with 110-130mm for the Highwood River Basin.

Alberta Rivers also issued a high stream flow advisory for the Sheep River.

High streamflow advisories are issued when stream levels are expected to rise rapidly, but no major flooding is expected.

Environment & Climate Change Canada meteorologist Terri Lang says it's tough to pin down exactly how much rainfall we'll see.

"Rainfall amounts are highly variable, especially in the foothills, it can be quite tricky to pin down some number. Certainly, rainfall amounts of 75mm are not out of the question with pockets of higher amounts possible by the time everything is said and done."

Last year's drought conditions could help absorb the rainfall into the ground, though according to Lang, it can do the opposite under the right conditions.

"Sometimes when it's been so dry for so long, the soil gets hardened and actually has difficulty absorbing the rain. It also depends on how fast the rain comes as well, a gentle rain is much easier to absorb than a heavy rain, as you can imagine."

Banff and Canmore are expected to be hit especially hard by the rainfall, with the snowpack expected to contribute to groundwater levels, and northeasterly winds creating more rainfall in upslope areas.

In terms of when the rain will subside, Lang says at the moment, it looks like we should see the last of it by the middle of the week.

"The rain will slowly taper off on Wednesday. We're going to get some really strong winds with that as well, something to keep in mind. It all should be said and done by Wednesday evening, or so."

She advises drivers to take it slow when driving through rain, with the rain and oil on the highways creating conditions for hydroplaning.