A Winter Storm WARNING has now been extended to include all of southern Alberta.
Hazardous winter conditions are expected.
Periods of heavy snow will begin tonight, with total amounts of 10 to 20 cm by Tuesday evening in the Lethbridge and Medicine Hat areas.
Snowfall with total accumulations of 30 to 50 cm is forecast by Tuesday evening in the southwest including Pincher Creek, Waterton, Claresholm areas.
Poor visibility will also occur as strong northerly winds develop on Tuesday morning. Gusts to 80 km/h are expected to produce blowing snow until late Tuesday afternoon.
Consider postponing non-essential travel until conditions improve. Rapidly accumulating snow could make travel difficult over some locations. Visibility will be suddenly reduced to near zero at times in heavy snow and blowing snow.