These photos were taken roughly 26 hours apart. The first, yesterday at around 3:00pm. The second, today just after 5:00pm. In the intervening time the lower river has risen approximately six feet and a large ice jam has begun to form.
Normally there is a drop of six to eight feet over the dam. Last time an ice jam formed there was no difference between upper and lower river for about two weeks, and then the ice lasted in some places into April.
The packed ice is still moving slowly, but I expect the frigid temperatures, which hit Grand Rapids last night, will freeze everything solid before daybreak tomorrow.