Buffalo, NY -- We get ice jams on the Niagara River when strong southwesterly winds flow down Lake Erie and push ice that's near the mouth of the river downstream.
The ice boom is at the mouth of the river and would normally stop the ice flow, but when winds are so strong and gusting more than 45 to 50 mph, the ice boom is actually designed to sink and let the ice pass, so the ice boom doesn't break.
So the strong winds push the ice down the Niagara River and often ice piles up on the east side of Grand Island where the river narrows, causing flooding behind the ice jam.
This is common, like right now, when the Lake Erie is just forming ice, since the new ice is more susceptible to moving. Once the lake freezes over the ice is solid so it doesn't move from strong wind events.
There was also some flooding along the Tonawanda Creek near the Niagara River in some parks, since the ice jam wouldn't let water out of the creek.
The flood threat is now over since the winds have weakened and ice isn't being pushed into the river anymore. But we could have another flood threat this weekend, widespread potentially, with a warm up and heavy rain.