An intense low pressure system off the northern tip of Vancouver Island is expected to move across the Rockies after midnight. As the system redevelops in Southern Alberta many forecast regions will experience a brief risk of freezing rain. The precipitation will then quickly transition to snow as upslope flow develops about the low. Snowfall accumulations of 10 cm or more should be expected by Wednesday for the City of Calgary, Kananaskis, Okotoks, Airdrie, Cardston, Lethbridge, and Cypress Hills forecast regions. As the low moves eastwards strong northerly winds will develop behind it generating widespread blowing snow in the City of Calgary, Airdrie Drumheller, Brooks, Okotoks, Lethbridge, Cardston, Medicine Hat and Cypress Hills regions.