Environment Canada upgraded its blowing snow advisory Dec. 17 to a winter storm warning for all of Prince Edward Island.
The weather agency said a slow-moving low-pressure system will track across Cape Breton Monday night and then south of Newfoundland on Tuesday.
Snow will intensify Monday evening ahead of the system and persist through Tuesday. Snowfall amounts of 20 to 30 cm are expected.
Gusty easterly winds will change to northwesterly winds and become very strong Tuesday, leading to reduced visibility in blowing snow.
Higher than normal water levels and rough pounding surf are expected for north-facing coasts Tuesday.
Visibility will be suddenly reduced to near zero at times in heavy snow and blowing snow.
Environment Canada advises to consider postponing non-essential travel until conditions improve.
Northumberland Ferries Ltd. has cancelled all crossings between Wood Islands and Caribou, N.S. for Tuesday, Dec. 18.