River flooding to persist well into spring 2019 over central US
This is an aerial of flooding taking place in Valley, Nebraska on March 16. People in the area were urged to "turn around, don't drown" when they encounter floodwaters blocking roads.
The recent bomb cyclone has set into motion the big surge of water that can keep most larger rivers above flood stage for many weeks this spring.
Rain and melting snow from the storm have already produced record-high water levels along portions of the Boyer and Floyd rivers in Iowa and the Big Blue and Loup rivers in Nebraska.
The Missouri River at Plattsmouth, Nebraska, (south of Omaha) has risen more than 3 feet above the record crest of 36.73 feet from late June 2011.
Dozens of other rivers are well out of their banks from northeastern Kansas, central Nebraska and southeastern South Dakota to southern Wisconsin and will remain so early this week.
These rivers and others flow into progressively larger rivers. Generally, the larger the waterway, the longer it takes for flooding to cycle through.
This year will be a notable flood year for much of the Mississippi, including its major tributaries such as the Ohio and Missouri rivers, factoring in flooding that has already occurred and what is likely to occur moving forward.
Heavy snowfall this winter and the upcoming spring thaw with episodes of heavy rain are escalating the river flooding concerns into the spring, including along the Mississippi, Missouri and lower Ohio rivers.
The Ohio River at Cairo, Illinois, has been above flood stage for many weeks and is expected to continue to fluctuate between major and moderate flood stage through the end of March.
However, the worst flooding may be yet to come for some areas along the upper and middle portions of the Mississippi River as much of the snow over the northern Plains, Upper Midwest and central High Plains melts.
A general 1-3 feet of snow is on the ground over the northern tier. Within that, there are 2-10 inches of water locked up in the snow from the Dakotas to northern Michigan as of the middle of March.
A road is flooded near Ceresco, Neb., Wednesday, March 13, 2019. (AP Photo/Nati Harnik)
At Rock Island, Illinois, there is a greater than 90 percent chance of major flooding along the Mississippi River during mid- to late April, according to National Weather Service hydrologists.
Significant flooding during the spring and early summer occurs roughly every three to five years along the Mississippi River.
However, widespread major flooding episodes occur roughly one to two times per decade along at least some portion of the mighty waterway.
Meanwhile, at Grand Forks, North Dakota, the Red River of the North has a nearly 90 percent chance of reaching major flood stage during the middle of April.
The Red River flows northward from a warmer climate to a colder climate like several rivers in Siberia. It is not uncommon for the headwaters to thaw before areas farther north. This can lead to significant lowland area flooding.
"From an agricultural standpoint, this is a 'wait and see' situation as to exactly how bad the flooding will be when planting time arrives," according to AccuWeather Agricultural Meteorologist Dale Mohler.
"Typically, even during years with widespread major river flooding, water only affects a fraction of agricultural lands," Mohler said. "However, there will likely be some patches well away from the rivers where water lingers in the fields for many weeks into the planting season."
In addition, the Mississippi River is used for transport of grains and other cargo. Tugboats can push multiple barges, more than a dozen, at one time. However, when river levels are high, the current is very strong. When this happens, the number of barges that can be pulled must be reduced and lowers the efficiency of the transportation method.
Farther south, multiple heavy rain events pushed river levels to moderate and major flood stage over portions of the Tennessee and lower Mississippi basins during the winter.
A school bus travels along a levee road near the Eagle Lake community near Vicksburg, Miss., Friday, March 1, 2019. (AP Photo/Rogelio V. Solis)
Looking ahead
"A break from major storms is forecast over much of the U.S. into Monday," according to AccuWeather Senior Meteorologist Brett Anderson.
This should help small rivers recede across the North Central states.
Some rain will return to the central Plains on Tuesday.
"While this storm will pale in comparison to last week's storm, there is the potential for 0.50 of an inch to 1 inch of rainfall in a narrow swath in the central Plains," according to AccuWeather Meteorologist Jim Andrews. "That could trigger new or aggravate problems if that rain targets the areas hit hardest by the flooding."
Larger rivers may rise slightly more than latest projections or their expected crests can be delayed.
"Already swollen smaller streams and rivers can also significantly rise," Andrews added.
Beyond the Tuesday storm, some additional rain may return around the start of the new weekend.
AccuWeather Lead Long-Range Meteorologist Paul Pastelok is concerned for another storm to follow and aggravate issues in the flood zones March 25-26.
Farther north, below-freezing temperatures at night will also help slow the rate of melting snow across the north this week.
However, with inevitable melting snow coming for the northern tier and large rivers already swollen from recent storms, a long-lasting flooding event is likely for many communities along the Mississippi River and others this spring.
Pastelok is concerned that more big storms with heavy rain may resume during late March to early April over the South Central states, which may renew or aggravate the flooding situation over the Tennessee and lower Mississippi valley region.
As a result, much of the length of the Mississippi River may experience flooding at the same time this spring.
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