A tornado warning has been issued for a part of southwestern Manitoba as much of the region is under a severe thunderstorm watch for Tuesday night while storms roll in from Saskatchewan and North Dakota.

Large hail, strong winds and heavy rains are expected, Environment and Climate Change Canada says.

Thunderstorms over parts of southeastern Saskatchewan and southern Manitoba are in the forecast until late Tuesday evening and potentially into Wednesday. They appeared non-severe at the time of the watch’s release shortly after noon CT, the weather agency said.

Forecasters predict the thunderstorms will unleash 30 to 50 millimetres of rain per hour, with wind gusts around 90 to 120 kilometres an hour, Environment Canada says.

The watch covers the province’s southwestern corner, stretching up near Russell and toward Lake Manitoba’s southwestern shores, past the outskirts of Winnipeg and ending near Steinbach. The cities of Brandon, Portage la Prairie, Morden and Winkler are included in the watch.

The storms are expected to intensify as they move northeast into Manitoba from Saskatchewan and North Dakota, with hail from four to six centimetres, strong gusty winds and heavy rainfall, the watch says.

A tornado or two “cannot be ruled out” as it’s unclear whether the storms will remain isolated or cluster together, the weather agency says.

People in the affected areas should be prepared for severe weather and are advised to take cover in a basement or interior room if threatening weather approaches. Those who are outside should take cover from flying debris or hail.

Severe thunderstorm watches are issued when conditions are likely to cause thunderstorms capable of producing damaging hail, wind or rain.