Cisco Sonar - Ice formation on Bear Lake

Debating as to whether Bear Lake will freeze it's always a matter of great discussion. When I first arrived 50 years ago it would typically freeze four out of five years. In the last 20 years the weather has moderated and freezing patterns have changed. Now it becomes ice covered less frequently.

Typically, as the surface of the lake approached 32° F, the fog would disappear. If we had a high pressure and no wind the lake would begin to skim from the shore. It would start over the shallow water in the north end and proceeded down the west side. Ice will then freeze off Gus Rich Point and Rendezvous Beach. As the cold continued, the entire lake would freeze but there will be open water off the Eden deltas due to the canyon winds. At any time, a storm and wind could break up the lake but the time to refreeze is shortened because of the millions of ice cubes floating around. For the lake to freeze totally overnight, the best scenario was a heavy snowstorm followed by sub- zero temperatures and dead calm. We haven't experienced that weather pattern recently, but the lake continues to freeze, so is the difference due to climate change? There are many different factors involved other than the air temperature. Factors like lake elevation, summer temperatures, heat budget, and weather during the fall and early winter.

I now think there's another factor involved that we have not considered in the past, lake elevation management. Frequently in the fall, water from Bear Lake is released into the Bear River for flood control and to make room for spring runoff. The warm surface water withdrawn from the lake with colder water remaining while with no lake inflow. If we get a cold winter with lots of snow, then it may be more likely to freeze.

This year the opposite is happening. PacifiCorp has not released any water out of the lake this fall. They are diverting warm (relatively thinking) Bear River inflow into Bear Lake to reach a target elevation in the spring. I don’t recall this scenario being used before. It should result in more warm water remaining in the lake.

If my theory is correct, Bear Lake will not freeze this year. If it does, then my theory is wrong. This is how we learn in science.