Here We Go Again
With the coronavirus outbreak curtailing world trade and the effects of the Phase I trade agreement between the U.S. and China still evolving, it wasn’t too much to hope that the weather would give barge operators a break.
But those hopes were, if not dashed, then at least subdued by the spring flood outlook released by the National Weather Service February 13.
Long-range flood outlooks issued by the NWS’s North Central and Missouri Basin River Forecast Centers said there is an above-average chance of widespread flooding this spring along stretches of the Mississippi River, Missouri River, Red River [of the north] and other tributaries in the northern and central U.S.
The flood potential for this spring is “well above normal” for the Upper Mississippi River drainage area. There is a persistent 50 percent or greater chance of major flooding along the Mississippi River down to Lock and Dam 19, and the same chance of moderate flooding from Lock and Dam 19 to St. Louis.
An extremely wet autumn—300 percent above normal precipitation in some areas—and super-saturated soils from the upper Midwest to the Lower Mississippi and Tennessee River valleys means there’s no absorption left. 2019 was the wettest year on record in five Midwestern states: Michigan, Minnesota, North Dakota, South Dakota and Wisconsin. 2019 was among the 10 wettest years in almost every state in the Mississippi, Missouri and Ohio valleys.
From Montana to the Southeast, soil moisture measurements are currently among the highest on record for mid-February. Rivers are still running high and above flood stage in some areas. Reservoirs are full, and some are still releasing 2019’s captured floodwaters.
Unlike last year, the Ohio River basin also has a higher risk of flooding, along with the Tennessee River valley.
In the upper Midwest, parts of the wet soil froze during a dry and cold November, and a later covering of snow insulated them from thawing. All this means any increase in rainfall will trigger immediate flooding. A brief warm spell in January and February has already produced ice jams and localized flooding along some tributaries of the Upper Mississippi. Along the Upper Mississippi, 49 gauges show a greater than 50 percent long-range risk of major flooding, and another 56 gauges show a greater than 50 percent of moderate flooding.
Snowpack in the upper Midwest is slightly below last year’s depths, but the water content of the snow is similar, according to NOAA’s Office of Water Prediction. March and April are usually the snowiest months in the Upper Midwest.
Last year, a “bomb cyclone” exacerbated all the existing conditions and made the floods worse. If unexpectedly heavy rains fall this year during the snowmelt period, they could create the conditions for flooding like last year’s, as could abrupt warm spells that release large amount of snow at once.
The only ray of hope held out for avoiding another spring flood season like last year’s came in the final caution by the NWS: “Conditions over the next 4-6 weeks will be key in determining just how the flooding situation will evolve.”
