Predicted by the NOAA via the National Weather Service a week ahead of the first floods, anyway. No, it’s not the kind of long range forecasting we could use for adaptation planning, but it’s enough in advance for citizens to prepare by evacuating, sandbagging, or whatever damage mitigation actions would be appropriate.

Much of the flooding in the northern states was caused by a combination of torrential rains and snow being melted by that rain. The risks due to this snow factor were recognized weeks before the February 20 warning by the Weather Service. Here’s how the Environmental News Service described the situation on March 20:

Above-normal flood potential is evident in much of the Mississippi River basin, the Ohio River basin, the lower Missouri River basin, Pennsylvania, New Jersey, most of New York, all of New England, and portions of the West, including Colorado and Idaho.

Heavy winter snow combined with recent rain indicates parts of Wisconsin and Illinois should see minor to moderate flooding, with as much as a 20 to 30 percent chance of major flooding on some rivers in southern Wisconsin and northern Illinois.

Current snow depth in some areas of upstate New York and New England is more than a foot greater than usual for this time of the year, which increases the potential for flooding in the Connecticut River Valley.

Locations in the mountains of Colorado and Idaho have 150 to 200 percent of average water contained in snowpack leading to a higher than normal flood potential.

Snowfall has been normal or above normal across most of the West this winter, however, preexisting dryness in many areas will prevent most flooding in this region, according to the National Weather Service. Runoff from snow pack is expected to improve stream flows compared to last year for the West.

During that week more than 250 communities in a dozen states were experiencing flood conditions.