Weather Tidbits: Ice Jam Formation
This Weather Tidbits describes how an ice jam is formed. Ice jams occur when warmer weather begins to break the ice apart; which will cause the ice flow to push downstream. The ice can become lodged in tight or curved areas creating the ice jam. The blockage reduces the flow of the river, resulting in flooding. Due to extreme temperature swings, ice jams are common from early winter with freeze-up jams to late spring with break-up jams. Freeze-up jams tend to produce from barely to minimum flooding; while break-up jams cause the most damage & flooding.