Weather Tidbits: Ice Jams

This edition of weather tidbits will be discussing ice jams. Long cold spells can cause rivers and lakes to freeze up. A thaw with rising temperatures can break the ice into chunks which can then become jammed within various portions of the water body, especially within sheltered inlets. The broken-up ice will flow downstream with the river current. But if there is a large accumulation of the broken ice at a point where the path is too narrow due to, for example, terrain, the water flow will be blocked. This blockage will reduce the flow of the river and cause the water level to rise. Ice jams can act as a dam, and thus can result in serious flooding if the water rises high enough.