The National Weather Service says a snowy winter and recent wet weather means the St. Croix River may see significant flooding this spring. After two years of almost constant drought, the St. Croix’s watershed has been somewhat saturated over the past few months.
As of Feb. 27, the North Central River Forecast Center puts the chances of a major flood on the lower river at about 40 percent. There is a nearly 90 percent chance it will hit at least minor flood stage. If it does reach that level, measured at 687 feet above sea level, it will be the first time in four years.
The drought that gripped much of the country and Midwest, including the St. Croix River watershed, for the past two years has almost been erased. The National Drought Monitor shows only a small part of the watershed still abnormally dry,
So far this winter, about 70 inches of snow have fallen in central Minnesota, making it the sixth snowiest on record. Duluth, near the headwaters of the St. Croix, has received 93 inches, 41 percent above normal. Several rain events have added more water than normal to the snowpack, with the highest “snow water equivalent” since record-keeping began in 1893. The melt will be significant when the weather warms.
The water content of snow on the ground in the region is approaching the top 10 percent of all time, the federal meteorologists say.
In its outlook statement on Feb. 22, the National Weather Service’s hydrologists said the chances of flooding had increased significantly in recent days.
The flood potential for much of Minnesota into northwest Wisconsin has shifted to above normal for this spring. The widespread and somewhat heavy rain that fell on top of our significant snowpack in mid-February added a half-inch to one inch of water to the system. And when you factor in this week’s storm, it will bring the risk up above normal. Snow water content is generally between 3 and 5 inches, but some areas are up closer to 6 inches, especially in northwest Wisconsin. This ranks in the top 10% historically for this time of year. The soil had been rather dry going into winter, but with a shallow frost depth and the fact that at least some of that rain and snow melt may have infiltrated the soil, the ground may be wet enough that more runoff could occur. Plus, we still have 6-8 more weeks of wintry weather to endure, so there is an enhanced possibility for minor to moderate flooding yet this spring.– NCRFC Spring Hydrologic Outlook: Updated February 22nd, 2023
An extended cold stretch during March is expected to keep a lot of the moisture locked on the landscape. Once the weather begins to warm up, the water will start to move toward the St. Croix, and residents and communities will be keeping a close eye on conditions. Stay tuned to St. Croix 360 for updates.